[sdunn]

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

[sdunn]

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.

 



 

[sdunn]

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

[sdunn]

And the battery box closed up

[sdunn]

Monitor and battery switch installed on back of passenger side cabinet:

[sdunn]

Solar connector takes the place of the old battery box vent (LifePO4 needs no venting)

[sdunn]

Slot for new 4AWG battery cable across the floor. I covered with flat aluminum stock, fastened to the wood subfloor

[albertr]

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

[BobB]

What are you doing/using for a Battery Management System (BMS) for the Lithiums cells?

[sdunn]

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

[BobB]

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/

[albertr]

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

[BobB]

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. 

[sdunn]

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.

[sdunn]

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.