Very close to finished with the wiring project. Couple more days and it'll be wrapped up. I'll do a write-up of what I've done when I'm finished.
Tried to charge up my LiFePO4 battery bank with a regular battery tender I had around the house. When charging up my AGMs, it would bring voltage up to ~14.2, which is about what my alt will put out, so I figured it would serve as a test. Unfortunately it seems these types of battery tenders are amperage controlled, not voltage controlled, so it was only charging the LiFePO4 bank at ~13.5 volts, but a full 5a, which was the tender's rating.
Data below. It looked like it was working despite the low voltage, as lithium banks should be charged at about 14.6v. Amperage was going into the battery bank (as registered by my battery monitor, and BMS), but after disconnecting the tender, the cells would balance themselves and the amp hours would drop.
Anyway, this proves you can't use a regular battery tender charge a LiFePO4 battery bank, at least not like the ones
@J Mack and I have.
Lifepo4 battery bank
13.2 at rest
13.4 charging at 58ah at 5a at 12:50pm
13.4 charging at 61ah at 5a at 1:26pm
13.4 charging at 66.5ah at 4.8a at 2:30pm
13.4 charging at 74ah at 4.9a at 4:00pm
**Hour break to cool off the tender**
**within this hour, the BMS registered amp hour charge level had dropped ~12ah despite there being no loads**
**I attribute this to cell balancing that occurs naturally when the cells are in series**
13.5 charging at 62.3ah at 5a at 5:10pm
13.5 charging through agms at 66.6ah at 3.5a at 6:03pm
13.4 charging at 66ah at 5a at 7:11
13.5 charging at 75.10ah at 5ah at 9pm
~3.3v cell voltage
*Disconnected for the night*
**Left connected to truck**
Settled at 64ah in the morning but cells are more balanced (voltage even across them)