I have 280ah of cells at 24 volts. Just going to run a 650 watt fridge and 90 watt TV, while driving. Alternator puts out 250 amps at 24 volts.
With all due respect to Captain Obvious, I also like to dive in first and then check to see what's in the water.
(Actually, I usually do some math so I have an idea of what I'm getting into. But when not trying to keep a business in the black, it can be OK to do something not perfectly optimized or right-sized, if you can afford to overbuild.)
Now that you've made your first purchase, all others have to be more carefully considered so they are compatible with the first one.
Next order of business for you, since you have a bunch of lithium cells and probably have an itchy wire-stripper finger, is do NOT connect those cells to anything until you have a BMS to protect them from over/under charge.
Read up on BMS, top-balancing, terminal bolt torque (stripped threads), poor contact to aluminum terminals.
Balancing may be optional. BMS will disconnect loads/charger to make sure the cells stay within correct voltage range.
If your cells have female threads in aluminum, you need to be careful with them. If they have studs, should be less of an issue.
Poor contact will make busbars get hot at high current, probably show up as low cell voltages on BMS.
Also, will your bus ever be in locations that freeze? If so, make sure BMS provides low temperature cut-out for charging.
That's one hell of an alternator. But can it deliver 250A continuous, or will that burn it up after a while?
Is 250A (almost 1C) acceptable for those cells? (even if so, it will not be at
40 degrees F, slightly above low-temperature cutout). <-edit
Read up on limiting/regulating current from an alternator. Maybe it should go through a charge controller with settings for LiFePO4. Maybe it should just have a long wire to add resistance, reduce peak current.
Unless you only drive one hour between camping sites and then consume 6 kWh, you don't need or want 250A charge current.
