How do I install a lithium bank

[SnowDrifter]

Coming in a little late

If you want to put lithium in your car, you need to do 2 things

1. Convert your alternator to external regulation
2. Ditch other batteries


1: lithium batteries have a different charge profile than lead-acid. They're Constant Current / Constant Voltage. Whereas lead/acid batteries charge up to a given voltage to accept a charge, then voltage is reduced once the charge is complete (float voltage or hot/cold alternator voltage). The general path to doing this is you gut the regulator, wire the plug directly to the brushes, and install something like a transpo 911-02r to handle alternator control. Aftermarket manufacturers like mechman or dc power make this quite easy on their units. But if you want to keep the stock alt, you'll need to do some homework here to determine if you need to modify a regulator, or if there's a part interchange that would function just as a brush holder

2. Said charge profiles and differences in resting voltages make it such that you shouldn't mix chemistries. Unless you want to discharge your lithiums every time you turn the key off, or when your alternator warms up. You can always get a dummy battery to take the place of the stock one - just an empty case with some terminals on it

[guidecca]

I'm trying to find out if there is a way to charge my lithium Iron Phosphate (LiFePO4) battery with a second optional 24v alternator.  I have a 2008 Ford Econoline E-250 van with four solar panels (400W) on the roof.  I want to add a 9000 BTU  mini split air conditioner on the rear bumper which will draw roughly 250 to 800 watts.  To power the mini split I need more power than the 400W on the roof and someone suggested adding a 24v alternator to charge the batteries while I'm driving.  Is there room in the engine compartment for a second alternator?   Any help is appreciated.