CaveVan Forum
VW T4 "Eurovans" => Westfalia => Topic started by: Cole on July 15, 2015, 10:08:06 am
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There seems to be some mystery out there about what the aux battery does, 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.
The Weekender (poptop) is the only version of the short wheelbase van in the USA to get an AUX battery.
It's located under the driver's seat and was intended to power the rear cabin lights, two rear 12v outlets (except on 1993), and the cool box that was located under the rear facing driver's side passenger seat.
The battery is connected to the vehicle charging system (alternator) by a relay. When the key is on the aux battery, main battery and alternator are all connected and charging. When the key is off, the two batteries are separated so that you don't drain the main starting battery while camping.
One of the mistakes people tend to make is using the radio while camped. The radio is connected to the main start battery and NOT the aux battery. You need to make some wiring modifications to change this.
Because many people remove the cool box, the aux battery goes largely unused. It's a fairly expensive battery to let waste away. For this reason, I think most average users would get more use out of a "solar generator" system like a Yeti 400. (provides 12v/120v outlets, etc.)
The driver's side seat base has a built in battery tray. It will accept a larger battery.Though the stock one is already too tall to run a seat swivel. So you need a shorter battery to do that.
If you also wanted to add a second house(aux) battery under the passenger seat you would need to source a second driver's side seat base for a factory like fit.
One of my favorite threads on house/Aux battery systems is this one from Expedition Portal. Lots of good basic info and diagrams there. Especially if you wanted to add solar to the van.
http://www.expeditionportal.com/forum/threads/77503-How-to-make-a-cheap-isolated-dual-battery-setup-for-50
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Ok, i bite and post.
I have recently installed the following:
- Solar panel (100w) on the roof (removable)
- Morningstar charge controller
- replaced aux battery with AGM SLA 1180 Interstate (65Ah) under the driver seat
- added second aux battery (same type) in parallel under the passenger seat
- added additional power outlets
- replaced rear facing driver side seat with ARB compressor fridge.
- added main fuse to protect sine wave inverter and ALL outlets that are driven off the aux battery
On order:
- Low voltage disconnect thingamagig to protect the newly added outlet under passenger seat.
Issues encountered:
- when changing battery to SLA 1180 you need to update the ground wire under the driver seat (original is too short)
- you also need to create / fabricate a strap/bracket to secure the battery. It does not have a lip like the OEM flooded
- when adding battery under passenger seat you need to run 4AWG wires between the seats. No issue in our van but if you have no rubber mat you need to figure out how to do that without tripping
- Also, you need a battery retaining system under the passenger seat. You can try to find an OEM battery tray or fabricate something.
- Its much easier to work it when you remove the seats. For that you ideally need a very low profile hex allen wrench with a small ratchet. the front bolts are half covered by the seat and its a bit of a pain to remove / reinstall.
- If you add fuses etc., make sure you make the wires long enough that you can access the fuse holders from the front of the seat once everything is reinstalled.
After much futzing it all seems to be working fine.
Details here:
http://www.vauweh.com
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Im in the process of putting in an aux battery. I've pretty much got it all wired up, but having some difficulty finding where to put the trigger wire for the isolator. Can anyone shed some light? I've tried a few circuits I figured wouldnt have power with key in off position, but each time I've found power there regardless (probably goes through a relay after the fuse box). Haven't been able to find much good info regarding the trigger wire either. If you know, please share, I'd appreciate it along any other fools that keep working on these vans. :)
Ill post my final project when its up and running.
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(https://farm9.staticflickr.com/8809/28364458801_277c4097df_z_d.jpg)
(https://farm8.staticflickr.com/7520/28351507462_6c7e5eede7_z_d.jpg)
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Cole, thanks for posting this -- helpful info.
I recently bought a Renogy solar panel suitcase (http://www.renogy.com/renogy-100-watt-12-volt-monocrystalline-foldable-solar-suitcase/) to supplement and charge our aux system when I'm in hardcore "parked, mobile office" mode. Took it on its maiden voyage this past weekend and like it so far -- simple, easy, and flexible in use.
Unrelated (and prior to) that, it's looking like our aux battery is needing replacement (it not been lasting long at all with the cooler on). My question for any and all: any recommendations re: battery type? i.e. should I be looking for a deep cycle battery / gel / etc.?
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If your seat base is not modified you have some options. Mostly your limitations are height and width.
I have replaced the OEM battery with an Interstate SLA 1180.
It fits nicely and is AGM. You will need to replace your ground wire with a longer one and need to rig up a simple way to secure it. Others have used slightly larger flooded batteries.
http://vauweh.com/wp/2015/07/21/more-on-batteries/
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Can I charge this auxiliary battery using an AC battery charger plugged into one of the cigarette lighter receptacles in the cabin? I'll be camping -- with no driving -- for a week, in a campground with AC, and I'd like to be able to use the battery for charging my electronics (iPad, phone) and running a DC fan (15 watt). I won't be using the battery to run a fridge or cooler. Just wondering if it's recommended to 'trickle charge' this battery if it's being used for camping, and the van won't be driven, for say a week or so.
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(https://c8.staticflickr.com/9/8369/29911998551_2039e5718e_c.jpg)
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Hi all,
Cole, nice job on installing those Yetis. Do you also use the house battery beneath your drivers seat or are you using the Yetis for all your house power needs? Also, do you think one could be fit beneath the driver side jumper seat if the cooler is removed? Thanks, Wes
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Most of the vans that got Yetis in them were either MV to Weekender top conversion vans. So they didn't have factory house batteries or they got shortened front seat bases with swivels which takes away the room for the factory house battery.
The Yeti 400 is about 8.5" tall.
The just released Yeti Lithium 400 is about 5.75" tall. So it may fit more places. I'm about to get one for a van I'm building so I should be able to let you know soon
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(https://uploads.tapatalk-cdn.com/20170706/03cc81d86f79760524e6aa0a36dfb19d.jpg)
Upgraded my aux battery with a Napa agm group 94R. It's 80ah and requires no modification for it to fit. At $210 it's a bit cheaper than the Interstate; especially when you consider you don't need to buy a hold down or new ground wire.
Sent from my iPhone using Tapatalk
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I'm upgrading and just bought a lithium battery for mine. It's a "drop-in" lithium which means it's internal "Battery Management System" is designed to work ok with a lead-acid oriented system.
I did a lot of research on drop-in LiFePo4 batteries (the type to use) and finally settled on the 100 ah "Battle Born Battery".
Both "Bay Marine Supply" and "Northern Az Wind and solar" sell it and both currently offer a discount over the US-based mfr's price, though you do have to ask Bay Marine for the discount. Bay Marine is a GREAT company to deal with, by the way, very helpful and the best prices around. Nothing against NAWS either, good folks.
100 AH might not sound like any great advantage considering the high initial cost ($850 shipped with discount), but these lithiums should give much more real usage for the AH rating, size and weight.
- you can draw lifepo4 batteries down all the way if you want with little issue, so 100 ah lifepo4 has more useable power than 200 ah lead. Most sources indicate that 100% DOD is not an issue when needed, but that 80% DOD will give the most cycles
- they hold their voltage up until the very end, so your fridge won't be cutting out early.
- they charge much faster to 100% and will soak up more amps when available, so smaller panels or shorter drives will still get you your full capacity back sooner. You don't have to "spoon-feed" them juice over long periods like the AGMs and other lead based batteries.
- unlike lead, they don't care if they don't get fully charged.
- minimal self-discharge
-longer life in storage
-many more cycles
Caveats: Just like lead, keep 'em cool to make 'em last. Don't charge when the the battery is frozen. Internal electronics on the Battle Born take care of the freeze factor. Mounting inside van keeps 'em cool.
Extensive comparison on value/capacity of lithiums vs AGM
https://www.victronenergy.com/blog/2015/03/30/batteries-lithium-ion-vs-agm/ (https://www.victronenergy.com/blog/2015/03/30/batteries-lithium-ion-vs-agm/)
I'm doing a solar setup as well myself, which I'll detail once I get it installed, but thought I would give a heads up now for anybody who is about to buy and unaware that lithium is maturing as an available tech and seems especially appropriate for smaller vehicles where small and light really do count. IF you have the $$$ for initial outlay, they might actually be more economical over the years.
From everything I have seen, these will probably give a long enough run-time for a fridge with no solar, just alternator charging if you are not boondocking for long periods. And though the alternator should charge the "drop-ins" decently as-is, because lithiums like different voltage levels than lead and mainly, no float charge, it seems that changing the relay over to something designed to work with lithium will get the longest life. The Victron Cyrix Li-charge is the one I'll using as recommended by Alan at Bay Marine:
https://baymarinesupply.com/victron-cyrix-li-intelligent-battery-combiners-for-lithium-systems.html (https://baymarinesupply.com/victron-cyrix-li-intelligent-battery-combiners-for-lithium-systems.html) I had originally ordered the Li-CT, but he called and convinced me to go with the Li-Charge as it's uni-directional and less issues than the bi-directional Li-CT
cheers
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Most of the vans that got Yetis in them were either MV to Weekender top conversion vans. So they didn't have factory house batteries or they got shortened front seat bases with swivels which takes away the room for the factory house battery.
The Yeti 400 is about 8.5" tall.
The just released Yeti Lithium 400 is about 5.75" tall. So it may fit more places. I'm about to get one for a van I'm building so I should be able to let you know soon
Hi Cole,
I currently own a '93 EV weekender. The house battery is toast and needs to be replaced if I want any power to the rear of the van. I am very interested in upgrading/modifying to solar/solar generator like the YETI's you installed previously. I also just purchased a 12V Fantastic vent fan and want to install it in the roof. When you install the Goal Zero YETIS are they tied into the existing house battery electrical system? I want to know if I can run the vent fan directly off the YETI or if it would be wiser to replace the house battery and tie in solar separately.
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I posted this on the ev_update yahoo group, but I went a different direction fixing my Aux battery after 17 years in my 2000MVWK. I got a $14 7AH lead-acid battery. I removed my cool box long ago, and I only use the Aux for the lights and sometimes running a 80W laptop inverter. 7AH will run out after about 4 hours of lights (theoretically, I haven't run the lights that long). I just pulled the connectors off the power port for the cool box and hooked them to the cheap battery.
The reason I did this fix is because the ancient Aux battery was pulling my Alternator voltage way down, and my main battery was only 75% full all the time. Replacing the old Aux brought the voltage up from low 13s to 14.2V...
This is not the perfect fix for everyone, but if you hardly use the Aux battery, but would still like lights occasionally, this should work quite well. I'll consider a Li-ion solution if they're cheaper when this one goes bad (probably in 3-7 years).
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Can you share some pics of how you connected this smaller auxiliary battery? I'd like to do the same thing because I only need it for my house lights and would like to better understand how you used the connectors from the cooler. Thanks
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A picture is worth a thousand words, alas, I cannot post anything with attachments. log into the ev update yahoo group.
All I did was move the spade wire connectors from the socket to the battery, red to red, brown wire to ground.
The old battery positive terminal connector needs to be isolated with tape or something.
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Finally getting around to posting some photos from last summer's install.
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My choice for a "drop-in" LiFEPO4 battery. $850 delivered is cheaper than Lead Acid per cycle and should outlast several sets of 100 amp lead-acid in one light battery.
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Ran 4ga from front battery as suggested. Prepped with padding, custom Simpson tie and duffle strap battery hold-down.
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Managed to get everything into that one compartment and mostly serviceable from front access panel. Very pleased with Victron components. Solar charge controller (MPPT 75/15) and Battery/system monitor (BMV702) both have bluetooth so I can monitor by app on my phone.
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Hi all. I just picked up a weekender (after a few years with an EVC) and am reading up on ideas related to all these topics. I'm curious if anyone has successfully installed a Yeti in place of the under seat cooler? This seems to me to be a very good place for it and would simplify connecting it up to the house battery (plan to eventually run solar).
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?? I thought that Yeti is basically just an upscale five day igloo cooler? Don't know how you'd power that, but there are chest style fridges some of which cost about the same as a yeti but actually have 12v compressors. I have one where the weekender seat fridge used to be. We got the shortest one to use it as a bench for the table.
Look at the Engels, Snomaster (low profile), Dometic. for a good fit.
Or off brands Edgestar /Winter on amazon to get a real fridge for virtuslly the same cost as one of those hyped up yeti coolers.
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Great thread on all the mods, I'll get there someday. :)
For now, I want to check the factory setup of my new EV -- what's the best way to test to be sure it's all working as it should?
Starting from the basics: When the ignition key is off or removed, can I assume the aux battery is working when the back internal lights work? Beyond that, what's next?
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Yep, if your house lights and lighter outlets in back are working when the engine of off, then it's all wired up and probably the battery is charging while running. Y ou can drop the little panel in the base of the driver's seat to see a few things, mostly fuses. Possibly you can check the house batter voltage by finding it's side of the relay.
I would pull the driver's seat to look at the house battery and check it's voltage and then run it down to whatever is 50% (not terribly familiar with lead acid) and see how many hours of use you are getting out of it.
The house battery can be upgraded in so many ways, it comes with the bare minimum. Also the wiring to that battery is thin.
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Thank you, SWSL. Just the sanity check of the lights gets me a long way. I've looked under the seat, just to visually inspect and make sure it's not a 25 year old mess of corrosion, battery acid and tootsie roll wrappers. It was surprisingly clean and the battery appeared relatively new...just had no idea how to know if the basics were working or not.
Once I get my dash put back in place after rebuilding the blender box, I'll test the battery further and start lining out the upgrades. There's always something! :o
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Once I get my dash put back in place after rebuilding the blender box,
I did mine a few months ago using the cut window approach from underneath. I figured that my well cared-for van would not need a heater core for some more years. Two months later, it went out. Now after all that contortion to avoid heavy disassembly I've got to take it all apart anyway.
So, do your heater core now! You won't regret it. Rockauto has best price I found.
For people that camp in the boonies a lot, have a "real" fridge and use solar, I highly recommend Battleborn batteries (or other quality LIFEPO4) for a house battery upgrade. Not just the increased capacity/weight-size ratio, but the quick charging profile, etc, etc., tremendously increased life in storage as well as life cycles in use. A good lithium battery should last ten years. Of course the value of a high performance house battery depends on your usage as well as budget for initial outlay. But worth considering before spending another $ on the old finicky lead acid tech. The Eurovan is a perfect candidate with the under seat location. Lithiums should be inside the vehicle, not outside it.
cheers