CaveVan Forum
VW T4 "Eurovans" => Winnebago "Full Campers" => Topic started by: Cole on July 15, 2015, 10:09:49 am
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There seems to be some mystery out there about what the aux battery does exactly in the Winnebago camper, how its hooked up, and what the upgrade options are.
Lets bring all the minds and resources together to create a great thread of information and resources on the topic.
If anyone has good links, diagrams or pictures please post them. If we have enough I will update this first post with all the resources for future owners to find.
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Cole, I'm about to finish my 2001 EVC upgrade (hopefully this weekend or early next week). Will let you know (with plenty of pictures) when it's completed.
-albertr
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That would be great. Since I don't have a Winnebago I don't have much direct experience with them. I would love to see lots of good information all piled in one easy place for people. As it stands now it's kinda hard to find it all.
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Cole, I'm willing to share my information as well. I still have the OEM battery box so can measure the dimensions and can tell you what've did for replacement. A lot depends on what loads the user has and expects to see, so maybe we can figure out a way to organize things based upon different "typical" loading scenarios. I pretty busy for the next month or so, so I may not be able to do much until things settle down here a bit.
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Don't know if David at 1705.net is registered, but he has a number of electrical upgrades on his site. One is the battery cutoff switch. I followed his instructions and took additional photos for reference.
See http://1705.net
I am thinking of tackling his converter upgrade. I am a relatively decent carpenter, okay with plumbing, but electrical schematics confound me. Others say "just follow the schematic" but that does not work. I had difficulty connecting his photos to a schematic, so I emailed back and forth with him to get the Winnebago "after" schematic done. I can share that, but it would really be helpful if someone has more detailed step-by-step photos.
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BobB thanks for the link to 1705.net. AlbertR has out me on the trail of dirty 12v power as a reason that my vitrifrigo may be cycling too frequently. Definitely going to do that converter upgrade, and replace the bad relay on my furnace while I am at it.
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sdunn
I can send/post the schematic I did (David did review it). The only caveat - David told me that the published Winnebago schematic may not agree with what's actually installed on your vehicle.
If you do the conversion, please take step by step photos for those of us who are electrically challenged. ;)
Also thinking I should upgrade battery to AGM at same time.
The biggest issue I have found with existing setup (and I don't think that will change with a new one) is charging when dry camping for extended time. This past June, we spent 2 weeks at Ocracoke NPS campground (no hookups). Driving into the village (3 miles each way) every other day or even every day was not enough to charge the battery. LEDs worked fine, but when I turned on water, the lights dimmed. I am thinking of adding the Westy Solar package. Yes, I could put together my own, but the Westy (80W system made by Zamp) has (1) carry case (2) controller panel is not on the solar panels, but designed to be mounted inside my EVC (3) includes extra long (50') cord (4) includes direct battery connectors, not just alligator clips and (5) has quick disconnect plugs to the panel.
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My EVC is still in the shop, but it wasn't able to keep the deep cycle battery charged while running the fridge on the last trip up to gold country….about 8 hours of driving…and for the rest of the trip is was low. Just got the car so it may just be an old battery. I'll be checking whether the deep cycle battery is good, or just replace it with a couple of golf cart batteries and check/change out the converter. I'm the same way as Bob with electrical…but basic stuff is doable.
-Need to add a battery cutoff switch (but that's just a splice).
-Also, I'd like to make one or both of the outlets on the plug in front of the stove run off the battery so the kids can plug in chargers, etc. for their devices. Depends on where the electrical is wired and how hard it is. I could just add another plug somewhere.
-I've got a nice solar panel my neighbor (who installs solar) gave me. A Siemans SP75 75watt panel. I'm considering mounting on the roof but right now I've got many other projects in the works. I also know I need some kind of controller to modify the output voltage, don't know what I need for that, but I haven't started researching yet. My neighbor will tell me what I need as well when it gets time.
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DRotblatt,
I did the cutoff switch per David's instructions on http://1705.net - straightforward and the particular switch he used is very well made (used on many boats). I found that the best tool to cut the hole in battery box was the saw blade on a swiss army knife - drill some starter holes and then hand saw around.
I am pretty sure the 12V outlet on the panel above the stove (only one on my EVC - you have 2? "both of the outlets") is off the house battery. Shows it that way on the schematic; it is where I plug my digital meter in to get a quick read of SOC. There is another at the rear of the EVC. The dash 12V outlet is off the engine battery.
Check GoPower - they have many accessories for solar panels - connectors, controllers, etc.
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Thanks Bob! Cutoff switch is a no brainer and many cheap options. But I do like the way David did it...easy access.
The EVC's in the shop still, so I can't look at it now, but I'm referring to the double plug below the stove - a standard 110V household plug. I believe that the book said that that ran on shore power only. There is a 12V plug (like a cigarette lighter) near it, and it's good to know that runs off the house battery. For my last trip, I plugged in an inverter and ran it off the 12V plug, but it would be nice to be able to plug in some 110V items (computers, etc) without the hassle of an inverter.
I just purchased two 6V golf cart batteries, and I'm shopping inverters. I'll install it in after I get back from my trip this coming weekend.
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Inverter question. David used the "Progressive Dynamics Intelli-Power model PD 9245C". I found another site (http://xochi.com/evc/battery-charger/) with some nice EVC builds (http://xochi.com/evc/) that shows basically the same installation, but uses a different inverter: the "ProMariner ProSport Gen 3 Dual battery Charger", I assume model #43020. (http://promariner.com/products/waterproof-on-board-marine-battery-chargers/prosport-series/)
Any thoughts as to which of the two would work best? The ProSport looks easier to install, both have similar intelligent charging and close prices. The Intelli-Power is 45 amp while the promariner is 20 amp but will charge the starter battery as well (though I'd have to run a long cable...)
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Dan,
110V duplex plug near fridge (and one at rear of EVC, too, on mine) only works when plugged into shore power. There is no inverter in stock EVC; the Magnatek unit that came with it is only a "power converter" (i.e. charger and not a "smart" at that ) - converting 110V to 12v to charge batteries when on shore power (I think I have that right?)
IIRC the PDI that David uses is not an inverter, but a power converter (smart charger). Disconnect your shore power and you have no 110v. An inverter would allow you to disconnect shore power and still run 110v off your 12v battery bank. I believe the ProMariner is also just a power converter, but that company also makes combination charger/ inverters
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I'm using yet another charger/inverter - Magnum MMS-1012, but I don't use its build-in 1kW inverter. I'm using a separate 0.3kW inverter - MorningStar SureSine-300. Morningstar has much less power loses comparing to Magnum during inversion process and 300W is sufficient for my needs (charging two laptops).
I use Magnum as a transfer switch/battery charger/ battery monitor. I have Magnum BMK (battery monitor kit) and RC-50 (remote control) which give me ability to always see SOC of the battery. That's one important number I need to know on a long camping trip.
Will publish a review of my electrical setup soon with more info.
-albertr
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Bob, thanks for the clarification, I didn't quite get it. Looked it up: Converter=AC->DC, Inverter=DC->AC. So the stock magnatek unit is a dumb primitive converter (which may no longer work), and the upgrades give you a smart better filtered converter. To get 110v during you drive you have to add an additional inverter. Got it. For now the converter upgrade is what I am going to do. The ProMariner is a smart power converter like David's PDI.
Alvetr, I looked up the magnum MMS-1012 and it looks cool and is both an inverter and converter. But at 5X the cost of the other chargers it's out of my price range. Love to see a write-up on it tho!
Anyone know anything about the ProMariner?
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I think we need some definitions here:
DC: direct current is electricity that flows in one direction. This is the the 12 volt system in the EVC. Always has a positive and negative.
AC: alternating current is electricity that alternates directions by constantly switching polarity usually 50 or 60 times a second (50 or 60 Hz). This is the "shore power" that you plug into. In North America this is 120 Volt. There is a "hot" wire that brings the electricity from where it is generated to the device and a neutral wire that completes the circuit but the electricity does not flow from one to the other as it is constantly switching.
Inverter: changes DC electricity to AC electricity.
Converter: changes AC electricity to DC electricity
Charger: a type of converter that is designed to charge batteries.
"Dumb" chargers are just converters that supply voltage a bit higher than the nominal battery voltage so that the charge flows into the battery. For a 12 volt system these should put out about 13.5 volts. This is what comes in the stock EVC.
"Smart" chargers will vary their voltage based upon the current draw. Drained batteries will draw more current than almost full batteries. These are much better for your batteries than the dumb chargers and with some attention and proper use, your batteries should last quite a long time 5-10 years or more.
If you want to plug a computer or TV or Blender into your EVC when not connected to shore power you will need an inverter to change the 12 VDC to AC. Actually, computers and most electronic devices run on DC and the charger you plug is a converter so if you plug in a computer into your inverter equipped EVC, the whole system changes from DC to AC and back to DC again!
The smart chargers may get confused if there are other draws on the system besides the battery it is designed to charge if the draw is large enough. If you plopped a nice smart charger straight into a stock EVC and ran the dometic fridge (technically an absorption refrigerator) in DC mode while plugged into shore power, the charger would see a draw of 10 amps or so and would assume the battery is very low even if your battery is completely topped off. If your draws are relatively low like electronic devices, LED lights, or a good compressor run refrigerator (e.g. TruckFridge or Vitrifrigo) then the smart should work as intended.
If you want to upgrade the stock EVC converter to smart charger for your AUX battery, then you should think about the entire electrical system and all the draws that you could have on it. There are converter/chargers out there that supply a 12 VDC power source as well as a battery charger but then you would have to change the wiring in your van to install it properly.
I got a dual smart charger that can charge both Aux battery and starter battery independently (ProMariner 20amp dual charger). It's a long run to the starter battery but was not too difficult to accomplish. I also replaced the stock fridge with a 2.5 amp TruckFridge to reduce my potential draw to something that would not alter the behavior of the charger.
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42pvan - Thanks - We should "sticky" those definitions somewhere so we are all using the same language!
albertr - saw photos elsewhere here of your battery setup - looking forward to a full review/description.
Drotblatt - The site xochi.com/evc/battery-charger/ was posted over on the Yahoo EVC group, but link now fails. It goes through a review of the Promariner. I have attached a pdf copy I saved a long time ago for your reference. Electricity is not my strong suit - Do not know if author is on this site, but recommend finding out (maybe log/join Yahoo EVC group) and contacting him for any updates.
Still have plans to upgrade my converter to a PDI per David, then see about new battery. Don't think an inverter required at this time. Phones, tablet and laptop can all be charged directly on 12V. No TV, microwaves or coffeemaker. Keeping it simple. Some point in future is new fridge, but when we dry camp we use old fashioned cooler (Engel) with ice. A block can last several days.
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I've just published the review of my solar panels setup: http://www.iral.com/~albertr/EVC/solar/solar.html
Will try to publish review of my battery/charger later today.
-albertr
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Sorry about delay, here's writeup on my battery/charger setup: http://www.iral.com/~albertr/EVC/battery/battery.html
Let me know if there're any questions.
-albertr
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42pvan...thanks, a good explanation. Question: if the norcold fridge is on (drawing 10 amps as you said), and the smart charger then thinks the battery is low and tries to charge it, is that a bad thing? Isn't it just helping to run the fridge, or will it put out too much power and overcharge the battery as well?
Bob...I don't have trouble with the link to xochi.com. Here it is:
http://xochi.com/evc/battery-charger/
http://xochi.com/evc/ works as well, but Xochi.com does not have any links to the evc section. The owner has probably changed his website and deleted the links.
albertr...I look forward to checking out the info on the solar as well as charger!
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DRotblatt... I'm not entirely sure what the Norcold actually draws but 10 amps seems about right as it has 20 amp fuses and the fridge uses heat to run. The smart chargers have 3-4 stages. For drained batteries they charge at >14.8V for rapid charging. When the battery gets close to full, the charger reduces voltage to 14.1-14.8V to complete the charge. After charging is complete, the charger reduces voltage to 13.0-13.8V to just maintain the charge. A fourth stage is on some chargers that, after charging is complete and it has been in the third stage for several days, increases voltage to >14.8V for a short period (a few minutes) to increase temperature of the acid in the battery so that the water moves around to prevent stratification and remove accumulated sulfate in the cells. So is it a bad thing to overcharge the battery? For short periods of time, no, it is really a good thing. If overcharged for too long though, you can ruin a battery by boiling off the acid and exposing the cells to air.
This is all for typical lead-acid batteries, and I'm not familiar enough with other battery types to say anything about those but I believe the process is similar.
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Thanks!
I looked up the amperage of the Norcold; it pulls 11.5-15 amps (page 2):
http://static1.1.sqspcdn.com/static/f/817849/14776484/1319418046177/3163service_manual.pdf?token=aNr7X8d%2FTWxtMXcVgHDXs06tdVU%3D
I guess the question is if the fridge is running, and it trips on the charger, how much power is it putting out vs what the fridge is pulling? At some point I'll change the fridge, so it won't matter. Until then, I guess the answer is to carry some distilled water and check the battery periodically to make sure there is no boil off of the fluid.
BTW: i have Lead Acid batteries - just bought two Interstate 6V golf cart batteries from Costco the other day. Will be installing them over the next two weeks.
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I went with a fairly simple approach, which may or may not work for others. We bought an 80 watt Sunforce panel on Amazon a few years ago on a whim. As luck would have it, the panel fit the width of the EVC perfectly. I spent many months trying to figure out how to mount it without putting holes in my roof. A friend helped fashion some brackets that we attached to the side of the roof without going through the roof. I opted for a permanent mount and sacrificed optimal sun positioning so as not to hassle with kids and dogs knocking over the panel. Plus, again as luck would have it, the skylight in my garage is positioned right over the panel, so I actually get a charged while parked. (Living in the sunny Southwest helps.)
Also, while there are certainly advantages to the higher quality controllers, I went with a $20-$25 Sunforce controller that seems to work just fine. Also opted to run the wires along the outside of the rear hatch to under the battery compartment then up through an existing hole the previous owner put in for a since-removed rear view camera. Again, wanted to avoid any holes.
While this simple set up may not be for everyone, I've found it to be a trouble- and hassle-free design that didn't break the bank. The house battery is always charged -- I only plug into shore power the night before a trip to cool the fridge -- and I never have to set up or move the panel.
Happy camping,
John
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Was looking at the PDI charger David recommended, but - as others have noted - the area where the Magnatek has water lines, etc. Since I do not want to get into relocation of the charger, I am thinking a "waterproof" marine charger, like the ProMariner might be best.
The ProMariner Prosport 12 dual battery charger comes highly recommended. So my questions are:
1. I am not going to include my engine battery in this upgrade - going to keep house systems separate from VW. - Will dual charger still work? I assume you just don't use the extra terminals?
2. How much charger amps? and what are real-world implications of different charging amps - time to charge the battery? Magnatek is 20A, PDI recommended by David is 45A, Promariner recommended is 12A. Or could go with their 20A one.
Any help appreciated. FYI - I am not electrically inclined.
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One thing to mention when charging the batteries - the max current batteries can absorb during bulk charging. I went with 50A charger because AGM batteries can take alot of current. If you are to use some other type of batteries you might want to take a look at that.
-albertr
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Right now I have an old flooded battery Thinking of getting a high quality AGM, like Lifeline, but probably not a really big battery; just the size to replace the one in the original box for now.
So keep it at 20A and under?
I did notice you have something like a 300AH bank + you upgraded to a 30 Amp plug? I am still using original 15 amp.
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Well, 120V*15A/14.3V=125A! Imho, much more than I need to charge my batteries. I did upgrade to a 30A shoreline socket, but that was not because I needed 30A AC, but rather because my Winnebago socket was rusted out and I had to replace it.
Here's a short writeup on my shoreline socket saga:
http://www.iral.com/~albertr/EVC/rust/shorelinesocket.html
The replacement I found in stainless steel was rated for 30A AC. I don't really need that much, but this Furrion socket looked nice.
I would check with your battery manufacturer on max current your battery can take... it would help to spec out the charger.
-albertr
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I have a ProMariner dual battery 20amp. I happen to have it wired to both the starter and house batteries but when I first put it in I only had it connected to the house battery and it works fine. You need to hook both sets of wires on the ProMariner to your house battery. If you just leave the extras unhooked the charger won't work because it first checks to make sure it is connected properly to good batteries.
With a good charger, I believe that a high amperage won't hurt your battery. The only problem is when the charger continues to supply high current when the battery is close to fully charged. A general sort of rule of thumb is that your charge current should not exceed your rated amp hours divided by 5. For my set up, with 225 amp hours I would not want to go above 45 amps (225/5). Some also recommend to divide by 10 rather than 5 so I should not exceed 22.5 amps. I think you would be fine to stay within these guidelines as long as you get a good 3 or 4 stage charger. More amps equals shorter charge times, and less amps increases charge time.
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Have not yet selected a battery, but for looked up info in Lifeline Technical Manual. They state "Due to the low impedance design, Lifeline batteries can tolerate in-rush current levels as high as 5C (500A for a 100Ah battery)"
This agrees with some other info I found that charging rate for flooded cell batteries is 8C or 10C and AGM's (like Lifeline) are 5C.
So I will do my homework - figure out my energy needs, select a battery (probably AGM), read the manufacturer's technical literature on charging, and then choose the charger.
Thanks for advice.
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Well, I did my homework.
Calculated my energy needs and came up with 2 basic scenarios, with and without a 12v fridge.
In all scenarios - Electric water pump runs sparingly and a 12v fan running all night. We currently do not have a 12v fridge, but use an Engel ice chest and it serves our needs for now. All our lights are now LEDs, and our iPhones, tablets can be charged about every 3rd day. We carry enough camera rechargeable batteries to last 2 weeks until we hook up to 110v. No inverter needed at this time. No microwave, no TV, no stereo running all the time.
Without refrigeration - 10 AH/day
With (future) refrigeration - 30AH/day
I assumed a 2.5A 12v fridge like a Truckfridge with a duty cycle of 8 hours per day.
Other assumptions / guesses
I don’t want to rip the entire back out. So the existing battery box stays for now. Current battery is 13”x7”x9+” high (could fit 10”)
If i am going to spend money it will be a high quality battery. Several Lifeline AGMs fit this space but I am thinking of the GPL-31XT with a 20 hours rate of 125AH. Might as get get most AH I can.
I think this will be fine for the Without Refrigeration scenario. We generally stay only 2-3 days at one place, driving around during the day and then on to the next place, so I figure that should be enough charging, if we don’t plug in. Obviously, with a fridge, the load really means I need to plug in more often or I might get solar for additional energy input. OR bigger battery bank. Fridge is off a bit for now, $ wise.
GPL-31XT Charging Instructions and Voltages:
Bulk Charge Voltages: 14.20 - 14.60v
Absorption Charge Voltages: 14.20 - 14.60volts
Float Charge Voltages: 13.10 - 13.40v
The GPL-31XT is designed for charging amperages up to 312.5 amps or 250% of the rated Amp Hour Capacity due to low battery internal resistance.
So which charger?
I was looking at the Prosport Gen3 chargers and the PDI 9200 series, that others have put into their EVC and been happy with. Also within budget. However, I noticed they have 2 very different charging profiles:
Prosport (profile for Flooded and AGM the same)
ProSport Charging: During this mode the “Charging” indicator will be red. ProSport will use all of its available charging amps (as controlled by temperature) until the battery voltage is raised to 14.6VDC (Flooded lead-acid factory setting).
ProSport Conditioning: During this mode the “Conditioning” status indicator will be amber. Batteries will hold at 14.6 VDC (factory set for Flooded lead-acid batteries) to complete charging while conditioning each battery connected. Upon completion the ProSport will go into its maintain mode.
ProSport Ready / Maintain: During this mode the “Ready/Maintain” status indicator will be green and remain on with the blue “power” LED indicating that your batteries are fully charged while being maintained at a precision 13.4 volts (factory set for Flooded lead-acid batteries) and are ready to go when you are.
ProSport Storage Recondition Mode: During this mode the ProSport “Recondition Mode” green indicator will illuminate with a slow fade in and out pulse indicating that while your batteries/boat are in storage the ProSport will automatically recondition all batteries for up to 3 hours once a month extending battery life and maximizing on the water battery power performance.
PDI 9200 Series
14.4 Volts (Boost Mode) – Returned the battery to 90% of full charge in approximately 8 hours. The battery reached full charge in approximately 11 hours.
13.6 Volts (Normal Mode) – Required 40 hours to return the battery to 90% of full charge and 78 hours to reach full charge.
13.2 Volts (Storage Mode) – Required 60 hours to return the battery to 90% of full charge and 100 hours to reach full charge.
EQUALIZATION MODE: When in storage mode the microprocessor automatically increases the output voltage to 14.4 volts for 15 minutes every 21 hours. This will help to reduce the buildup of sulfation on the battery plates.
Is PDI “Normal” the same as Prosport “Conditioning”? If so, how will the lower PDI "normal" charge of 13.6 affect the batteries?
Any advice will be appreciated.
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Bob…I got the progressive dynamics PD9245CV, but haven't installed it yet. But can't answer your questions, I'm just assuming they would both work well, and this one worked for 42pvan (?).
FYI, I just put in two 6v golf batteries side by side (Costco, about 240AH). Very little modification to car. Had to cut one aluminum brace form the inside of the cover and replace with steel 1/8" flat bar, but otherwise fit where old battery is and leaves an inch or two more for storage then the old box. There was some modification to the battery box to add vent, drain and allow the top to fit. I'll be doing a write-up with pics after I get back from Central Calif trip (leaving tomorrow).
Excuse all the tools and crap in the pics...
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Dan,
Thanks for prompt response. Will be interested in your work with the PDI installation. Please post photos after you do it.
Where did you get box? Where did you get the battery disconnect switch? Looks like the kind on some sailboats (French - Beneteau, Jeanneau, Dufour)
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The parts I ordered/purchased are:
-2 6V golf cart batteries from Costco
-Stinger SGP38 80-AMP Battery Isolator and Relay from Amazon.com
-Battery box: http://www.allbatterysalesandservice.com/browse.cfm/4,573.html
-2 of Camco 47440 Black 5/16" Stud 18" Long 4-Gauge Marine Battery Cable and Lug Assembly Tinned from Amazon
-E Support Car Battery Isolator Disconnect Cut OFF Power Kill Switch (amazon.com)
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Dan,
oops. Just found that info under your name in the "Coach Battery Upgrade and Rewire Questions" Subject.
Thanks.
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Here's a write-up of my double 6V golf cart battery install in anyone is interested. I'll add the relay after I take a pic of it.
http://www.rotblattsculpture.com/eurovanbatteryin.html
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Does anyone have any strong opinions on how to mount the Solar Panels?
I'm preparing for a 4 month road trip and want to add solar to my rig to compliment my new 12v fridge. I'm thinking about mounting them on the roof rack using Yakima Canoe brackets so that I can somewhat easily remove the panels to move them into sunlight as needed.
Does anyone have any experience doing something like that?
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So, Cole- feel free to move this if its worthy of its own thread. I just would like to learn more about House Battery options before I go with a direct replacement of the original Trojan in my 03 EVC.
I read the related threads on upgrades and solar, etc etc. Still slightly confused on options for direct replacement. Basically, I am after 1 thing and that is longer run time of the stock systems while off the grid.
Im not looking to run solar
Im not looking to run TV's and blenders
So, my questions are;
Can I just fit a larger Trojan 12v?
I see many folks doing two 6v Golf Cart batteries... advantages over a single battery? and does the stock charging system need to be changed?
I see a master power switch mod- is this just to prevent any ghost draws on the battery?
Before I drop the money on a new Trojan, Im just looking at options since I hope to not have to do this again for a few years at least!
Cheers from Maine :) Josh
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Sorry about delay, here's writeup on my battery/charger setup: http://www.iral.com/~albertr/EVC/battery/battery.html
Let me know if there're any questions.
-albertr
Albert,
This is amazing stuff. I want to build something very much like this. What were the specific reasons you chose the Magnum instead of the Promariner Dual charger? Anything aside from the higher current? I like the dual (house and starting) battery charging aspect of the Promariner (aside from the price). If higher current was the main (only?) reason, then what have your charging times been after discharge? Enough of a difference to justify the price difference?
Also, looks like you lost quite a bit of storage space in the rear battery compartment? I use that room to carry chocks, grey water drain, jump start cables, some tools, hammer, cordless drill, etc. Did you find the reduction in storage room noticeable? Were you able to use the now empty magnetek area to stash some stuff?
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I've seen Magnum chargers used in camper conversion projects before. With cost of AGM batteries, saving money by picking less expensive charger was not important to me, so I went with Magnum simply because it's known to work.
I didn't actively use battery compartment for storing stuff before, but you are right, it had some useful storage space which was lost after my conversion.
-albertr
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Has anyone successfully converted house battery to LifePO4? I'm in the middle of replacing my failed Magnetek, have the whole back end of the van disassembled, and now I need to commit to the new build.
Options are *roughly*
2x 250ah 6v Flooded Lead Acid at about $150 each = $300; ruled out for laziness and safety
2x 250ah 6v AGM at a little under $300 each = $600; highly available well-known charging equipment
2x 100ah 6v LifePo4 at a little over $600 each; Plus maybe battery mgmt and a DC-DC LifePO4 charger
(there are those who claim 100ah of LifePO4 is more capacity than 250ah of AGM)
LifePO4 seems like it is clearly the future, but very bleeding edge right now. The expedition portal forums have people who are just starting to make the switch. Given the upfront cost, it takes a pretty big leap of faith.
The (supposed) upside is that LifePO4 has much deeper depth of discharge than AGM (down to 20% or less vs. 50%) and LifePO4 gives you full voltage until it is empty. And, WEIGHT is perhaps 1/3 that of AGM!
While I hesitate to drop $600 on the AGMs that I may regret in two years. Wondering if anyone has made this work.
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Lithium batteries certainly look attractive. I went with AGM batteries simply because it was proven and known to work. I use two changers on regular basis (Morningstar and Magnum) and they both play nicely with each other (can have them both changing batteries at the same time). You might want to research chargers for LifePO4, is there any MPPT controller which supports charging LifePO4 batteries?
-albertr
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Well I decided to pull the trigger on LifePO4 - will post as the components come in and I install. While I flirted with a coach electrical system redesign, the dollars for what I had in mind started adding up too fast, so I backed off and am treating this strictly as a repair of the failed Magnetek and house battery. Even so, it is pricey. LifePO4 definitely has traction in the yacht world, and is gaining traction in the Class A motorhome world.
My goal is to be able to keep the Vitrifrigo cold, run the lights at night, and charge devices, for at least 3 days without starting the engine or accessing shore power. Design-wise the battery capacity can scale up later without throwing the first build out, but using Solar to recharge anything bigger than what I'm planning isn't practical.
So here's the plan: get a *usable* 144Ah (when new) out of the following:
4x 180Ah 3.2v LifePO4 cells wired in series
Progressive Dynamics PD9180AL 80 Amp, 12 volt, Lithium Ion Converter/Charger
Victron BMV700 Battery Monitor
BlueSea 6006200 Battery Switch
Zamp RoofSide Solar Port (hardwired into charge controller)
Zamp portable solar system (size TBD)
This design will require no metal cutting, and the LifePO4 cells are so small they will fit inside the OEM battery box. I'm buying cells (vs. a pack) to save money. There is much discussion as to whether you need a battery management system and balancing tools when you assemble these cells into packs. I'm buying from a supplier that serves the custom electric vehicle market, and they are confident that for what I'm doing I can just wire them up in series and hook up to a charger. More to come! This is my early-summer project
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Sounds great! Looking forward to your build and report.
-albertr
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For reference - I hadn't seen the Winnebago coach wiring diagram posted on this thread. It is almost 100% correct for my 99. Here it is.
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And so far my least favorite design attribute of the winnebago implementation: what the wiring diagram refers to simply as an 'isolated stud' - this is the common post that ties together the output from the alternator and charger with the positive battery cable and the 12v circuit breaker panel.
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The rub is that with the Lithium batteries, I can charge them at a very high DC amperage (as high as 300a DC / roughly 30a AC), so I want a faster charger when I'm on shore power, so the Progressive Dynamics charger I'm installing is 80a DC. But the OEM battery fusing is 40a DC. One cable in & out. So what would be nice is to have a switch between charge and discharge, and fuse accordingly, but that adds cost and operational complexity, tradeoffs, etc.
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OK - it's all together and seems to work. I need to perform a couple of run-down tests. Loving the Victron monitor - pricey, but really cool tracking of amp-hours in and out of battery. I have been trying to post the build process with pics but the cavevan server keeps errorring out. I have notified Cole
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I can start with some resources. For the Eurovan mods, these are all excellent:
http://www.rotblattsculpture.com/eurovanbatteryin.html
http://1705.net/archives/466
http://xochi.com/evc/battery-charger/
Plus AlbertR's material in this very thread.
Specific to Lithium cells,
http://www.technomadia.com/lithium/ - START HERE - these folks are early adopters of LifePO4 for coach batteries, and true DIY-ers. They have other resources on their site
http://store.evtv.me/index.php - This is where I bought my 180ah cells. Their core business is EV conversion support, but they will happily sell you just a few cells and they have great documentation.
http://www.bestconverter.com/PD9180AL-80-Amp-12-volt-Lithium-Ion-ConverterCharger_p_607.html#.V23ix5MrJsM This is the converter i settled on. Works great
http://shop.pkys.com/Victron-Energy-BMV700-Precision-Battery-Monitor_p_2810.html?gclid=COXEuumHws0CFVBffgodsh4E6g This is the battery monitor. BTW, Peter Kennedy Yacht Services (PKYS) despite the name, has very competitive prices.
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The finished battery box, with the lithium cells. If it looks like a lot of wiring, it's because I wanted a bus for both the positive and negative connections (to be able to cut off the solar generation with the same master battery switch and for possible future accessories) and the battery switch adds a cable or two. Plus there is a shunt inside the box for the monitor - sits between the negative battery terminal and the chassis ground, and has a connection to the positive terminal
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And the battery box closed up
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Monitor and battery switch installed on back of passenger side cabinet:
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Solar connector takes the place of the old battery box vent (LifePO4 needs no venting)
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Slot for new 4AWG battery cable across the floor. I covered with flat aluminum stock, fastened to the wood subfloor
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Good information! Which solar controller you are planning to use for LifePO4 batteries?
On a side note, I would strongly advise against using flexible/bendable solar panels. I got the second panel overheating and burning, this time it managed to do some damage to EVC plastic roof. So, I'm in the process of redoing my solar setup to dump flexible panels and replace them with a single large glass panel.
-albertr
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What are you doing/using for a Battery Management System (BMS) for the Lithiums cells?
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For the Solar, I'm *very likely* going to use Zamp, which is what GoWesty resells. They are glass panels and kitted with an all-weather charge controller that is external to the van. That's why I can get away with just the connector on the van - everything else is externalized and portable. Not cheap though. I don't have to use Zamp, so I'll keep looking.
For battery management, I am going with the advice of EVTV, who says you don't really need one, and their applications (driving motors for cars) are much more strenuous than mine. having said that, I suspect that if you go to parallel strings (which I would have to if I wanted more than 180 amp-hours), I think it is more complicated to get all of the juice in and out of the battery bank. With my four-cell series setup, it is much more simple
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I will be interested in how your lithiums do with no BMS. Every article/blog I read (including some of your referenced ones) talks of BMS as a "must-have". Most 12V lithiums come with a BMS built in. Keep us posted.
The zamp kit from GoWesty seems great, but as far as I know the controller is for Lead acid batteries. Zamp now has a new controller just for lithiums - http://www.zampsolar.com/product/lithium-ready-dual-battery-charging-30-amp-solar-charge-controller/
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Zamp says that their controller supports Li and LifePO4, but it doesn't look that it has a separate connection for each battery cell. Not sure how it can balance cells without ability to charge them separately.
-albertr
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Albert,
Not sure, but I think the Zamp works connected to a single 12V battery bank (even if made up of several 12v batteries in parallel) - a BMS (or EMS as sometimes referred to) is necessary to balance the individual cells. The Zamp does not balance the LiFEPO4 cells, it just provides a chargin profile suitable for LiFEPO4 batteries. On some other forums, people have been connecting it to banks made up of 12V LiFePO4 units, each with integral BMS. Other than Technomadia, who made their 12v units up from individual 3.2 v cells, most have been buying 12V units from places like Stark.
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I'll let you know in a year ;)
Again, just going off of EVTV's recommendations, they claim that ongoing balancing is not necessary. They do recommend an initial "bottom balancing" of the cells before you string them together (basically draining them individually to a specific voltage), but after that, no special treatment, other than don't overcharge and don't drain to zero.
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This is EVTV's usage guide. Super useful in terms of understanding LifePO4 voltages, what "full" means, how low you can discharge prior to damage, etc. Battery monitor is critical if you are going to make this investment.
It is early days yet, but the difference between the lithium and my (admittedly compromised) deep-cycle is profound. In the old setup, the Vitrifrigo really couldn't maintain temperature on battery only (no doubt because the old deep-cycle struggled to maintain 12 volts). On the lithium, not only will it maintain, it will actually drop the temperature (right now sitting at 34F with ambient 78F) while using up about 3.5 amps per hour. I haven't run it down yet, but that would mean I can go 40 hours straight with no recharge. Adding in Solar should extend that by a TBD amount. I am thius pretty optimistic about my 3-day off-grid goal at this point.
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First rundown test:
Voltage at start: 13.23
Amp-Hours used: 28.4
Elapsed time: 8.5 hours
Voltage at end: 13.12
For now, 12.00 volts is going to be my "don't go below" number. Looking promising.
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Did you do the "bottom balancing"? how did that go?
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Albert,
Not sure, but I think the Zamp works connected to a single 12V battery bank (even if made up of several 12v batteries in parallel) - a BMS (or EMS as sometimes referred to) is necessary to balance the individual cells. The Zamp does not balance the LiFEPO4 cells, it just provides a chargin profile suitable for LiFEPO4 batteries. On some other forums, people have been connecting it to banks made up of 12V LiFePO4 units, each with integral BMS. Other than Technomadia, who made their 12v units up from individual 3.2 v cells, most have been buying 12V units from places like Stark.
I took a look at Stark Power and Smart Battery, and I'm not sure if they have a real system to balance cells either... Based on the pictures available on their websites it looks more like overvoltage/undervoltage/termal protection? Looks like they are building their batteries using many small cells, so if their battery comprises a few dozen of small cells (some connected in series, other connected in parallel), how much would the cost of complicated system to individually balance and maintain them?
I'm curious if these Chinese cells from EVTV are also build from many small cells connected in parallel?
On a side note, cheap Chinese LifePO4 18500 can be found for a couple of bucks a piece, if anyone can design and manufacture a controller which can monitor/balance/maintain/charge a few dozen of 18500 cells, it might be an interesting DYI project to build a LifePO4 battery out of them. Additional benefit would be very low cost of maintenance and repair. If controller has ability to automatically identify a bad/degraded cell, just swap it out with a brand new spare 18500! Can easily be done in the field.
-albertr
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BobB: Have not yet done the bottom balance. You can do it at any time so long as you have not damaged any of the cells. My pack is so small and easy to break down that I got impatient and wanted to see it perform. In an EV application, with perhaps dozens of these cells, once you assemble you are highly unlikely to break it back down, so probably important to do it upfront there. If I get capacity that I am happy with (and I can watch voltage very carefully) I may never do the balancing.
AlbertR: The CALB cells are single cells. 180 ah is currently the biggest available, although if you are set up to do business on Alibaba, I think I saw some 200 ah cells there. In a year I wouldn't be surprised to see 250AH widely available.
As near as I can tell, bigger is better with respect to AH/cell volume and $/AH. When I bought my 180s, EVTV had some 100AH cells on a closeout deal, but the 180s turned out to be very similar in $/AH, and I get the simplicity of a 4-cell pack.
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I took a look at Stark Power and Smart Battery, and I'm not sure if they have a real system to balance cells either... Based on the pictures available on their websites it looks more like overvoltage/undervoltage/termal protection? Looks like they are building their batteries using many small cells, so if their battery comprises a few dozen of small cells (some connected in series, other connected in parallel), how much would the cost of complicated system to individually balance and maintain them?
-albertr
Albert - on the Stark site they say:
"StarkPower “DEEP CYCLE” Models have a Battery Management System (BMS.) BMS monitors the key operational parameters during charging and discharging such as voltages, currents and internal temperatures.
There are three main objectives common to all Battery Management Systems (BMS):
Protect the cells in the battery from damage through overcharging or discharging too low.
Prolong the life of the battery with cell balancing.
Maintain the battery in a safe operating state."
This "BMS" or "no BMS" is an interesting discussion. On other RV forums I follow, it is always "must have BMS". Have never seen/read/heard the "no BMS" topic before. This discussion seems particular to forums/blogs on electric vehicles. Just wonder if the type of use/power demand for electric vehicles has anything to do with it. RV use is for lights, fans, fridge, run an inverter for some 120V appliance, etc.
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In my humble opinion, which is worth exactly what I charge for it ;) ....companies like Stark are making "drop-in replacement" batteries, which are designed to have *some* tolerance for operator neglect or just plain indifference. It may very well be the case that if you are going to sell a "drop it in and forget about it" product, the BMS is a very good idea.
Also, if I have a class A coach with a 500AH or higher pack, then that is a very large investment, and I may think that a BMS protects that investment. I've yet to see data that proves anything one way or the other.
At present, the premium for that kind of product is high (vs. DIY-ing it) and I'm willing to pay close attention to my pack in order to get the potential benefits at lower cost. I'd bet that anyone who is wants to build their own EV (convert an existing gas-fired car) is similarly willing to pay a lot of attention to what's happening "under the hood".
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Update on run down test:
To go from 13.23 starting voltage to 12.8 ("nameplate" voltage on the pack) I used up 71 amp hours. With the Vitrifrigo running non-stop at 3.5 amps, that would 20 hours of wall clock time. However the vitrifrigo is going to be much closer to 1.5 amps over a a 1 hour period, so I think that will give me roughly 40 hours of runtime with no solar re-charge.
Next step is to see how many amp hours are used up going from 12.8 to 12.0, which is going to be my cutoff. The vitrifrigo won't cut out until voltage gets to about 11.0, so I have to monitor and hit the battery switch to protect the pack.
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Update on the Zamp charge controllers & Lithium profiles for AlbertR. They are 'targeting' 'beginning of 2017' for having the Lithium profile on all of their controllers.
So, if I want one *now* it means mounting the non-weatherized lithium charge controller on the same plastic panel as my monitor & battery switch. I thought this could be an outcome, so I already have the splice between the Zamp plug on the outside and the battery busses. I just need to unplug and plug into the charge controller and I'm all set.
BTW, I stopped my rundown test at 12.5v and 91 amp-hours used. Hard to say exactly, but given what i saw, starting from a "full charge" of 13.6V, I should at least be within spitting distance of my predicted 144 amp-hour capacity. I'm going to call this whole thing a preliminary success. ;D ;D ;D
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I'm wondering if were considering adding some programmable BMS like the one below?
http://www.ebay.com/itm/Lifepo4-Li-ion-Lipo-1S-4S-BMS-Programmable-With-LCD-Monitoring-/151644551555
-albertr
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First field test for the LifePO4 battery. I sort of chickened out and added the solar before my first trip (200watts of Renogy suitcase solar; Genasun Lithium charge controller)
Long story short: Conditions were optimal (lots of sunshine, warm nights with no need to run the furnace), but with a load of the Vitrifrigo C60iac, interior lights, constant charging of laptop and 3 iDevices, I made more power than I consumed - the battery never dropped below 13.2 volts, even first thing in the morning.
Next test will be shorter days, and I'm going to add a 2000w inverter so that wife can run a blow dryer. I still expect to have essentially indefinite power.
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Hi Everyone,
I'm a newbie at this topic and I own a 1999 EVC. I will be asking some basic questions and if you have the time, please let me know and if you don't that is ok.
The first question I have is: If the EVC comes with a battery isolator, why are people purchasing the Stinger battery isolator? Is that to replace it? Or is the existing one not good enough? Or it won't handle the load?
Thank you,
Miquel
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What a good thread! Thanks to Albert for the write ups that I hadn't seen before. He ran into similar issues that I did (but planned his install a lot better than me!)
I ended up fitting 4 x 50W lexun flexible solar panels as they more or less exactly fit the width of the central roof section. Only gets me 200w of course in a series/parallel arrangement.
I started off with a larger panel but it wasn't large enough so it came off and the 200w array went on.
I also went from a Ctek D250SA solar charger + split charge controller to a victron energy Smart Solar MPPT 75/15 as this gives me load and solar monitoring over bluetooth. It has given me a much better picture of my loads and what I can get out of the 200w panels and has charge curves and battery protection customisable to lead acid/agm and lithium.
I also went from a 110AH lead acid to a 130AH lithium. The lead acid wasn't storing anywhere like the energy it should have. My monitoring has only run a few months so far but on a trip my daily usage can hit nearly 400Wh which is basically Vitrifrigo C60i fridge and the stock Suburban furnace + some LED lighting. That was about all the lead acid held in winter.. .
Next to go on is a Victron Battery monitor, this will give me better battery monitoring but will also disconnect the alternator charging when I hit a preset level to prevent overcharging.
At some point I intend to start writing up some of my own installations. . . . .
As a European, I actually ended up ripping out all the 110v stuff and have not had any reason to put mains back for what I do.
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