Lithium battery Install/Results

[Bob K]

Originally Posted by sthomas

Next, I wanted to test how well the stock converter would charge the lithium battery. I ran the battery down, then plugged the trailer in. I had the solar turned off, but the trailer still connected. Nothing was running in the trailer except the propane detector. Fridge is off.

You can see the battery started at 67% with a 0.29 load (propane detector I guess). I plugged the trailer in, and it started charging at 4.52A. After about 2 hours, it settled down to 3.99A. I let it sit overnight, and this morning it is showing 0 and battery is 93.74% charged. During the charging, I tested the actual V to be 13.37V.

I'm not very happy with the charge rate. The Converter says it will boost charge at 14.4V - but I didn't see anything close to that. I did not measure V at the converter, but I assume there is a 1V loss in the wiring.

I am happy with the final result of ~94% charged though. My solar panels can easily top the battery up if needed. I will probably only turn my panels on when I am off-grid.

Originally Posted by 16WhiteColly

Per google search, the stock 8735 will not charge them.

It does charge lithium batteries as shown by sthomas' results; however, we know that it's not designed to charge lithium and the results seem to be variable based on a particular battery and its particular charge voltage. We're working to discover what the unintended results are.

I'm excited about that WFCO 8735lis lithium charger. Looks to be a direct replacement.

[16WhiteColly]

Wow, that’s a double whammy having to buy another convertor after buying an expensive lithium battery.

[Grumpy]

Originally Posted by 16WhiteColly

Per google search, the stock 8735 will not charge them.

X-2 None of the stock converters that JAYCO uses will work properly on lithium batteries, only wet cell and AGM. All need modification or replacment for lithium.

[craigav]

My setup is still work in progress. With that in mind, the converter in my RV also will not charge the Lifepo4 batteries to 100%, it appears that the converter puts out more voltage when first turned on and then backs down ~13.4v after a few hours (maybe 4, I have not timed it).

In any case, it is better to not maintain a Lifepo4 battery at 100% SOC for long durations (forever) in order to obtain the longest life out of them, and with that in mind I purchased a PowerMax PM3-100 converter charger that has an adjustable voltage and ~100a output.

Here is my plan, use the Jayco converter most often and not change anything with it, which will keep the Lifepo4 batteries closer to ~50% (+ or - ~15%) and then leverage the PowerMax charge\converter for those times when I want the Lifepo4 batteries to charge all the way to 100%. I don't intend to charge them to 100% except when I know I will not be on shore power for any extended time period and seeing how I stay plugged in when at home or in a campground I don't have to keep the Lifepo4 batteries at 100% for any extended time period which should allow for a longer life out of them. I will charge them to 100% prior to any camping where I don't have shore power, and with the 100a charge rate it shouldn't take too long to charge them even off of the generator as I many times use for an hour (or so) in the morning and in the evening.

I also have a Renogy 40a dc2dc charger that I will use while travelling and attach a switch to it, same thoughts, only charge to 100% if I believe I will need the Lifepo4's to be at 100% that night or soon, otherwise I will turn off the dc2dc charger before the Lifepo4's reach 100%, back to somewhere nearer the 50% SOC range.

~CA

https://www.amazon.com/PowerMax-PM3-...3D&sr=1-2&th=1

[Bob K]

Originally Posted by Grumpy

X-2 None of the stock converters that JAYCO uses will work properly on lithium batteries, only wet cell and AGM. All need modification or replacment for lithium.

Correct, where "properly" means "won't get the batteries to 100% SOC." They'll get them to some lower level SOC.