Charging LiFePO4 with your alternator

jcdostie

Member
Hi
What do I need to charge from my alternator’s truck (200A 12V) to my Lithium Batteries ?

Tks
JC


Envoyé de mon iPhone en utilisant Tapatalk
 

AbleGuy

Wayfaring Stranger
I just recently met a guy boondocking who is working out of his customized camper, who had built, installed and configured his own LiOn battery system for working via computers while on the road for the next year. He even built his own batteries.

He patiently took time to (try) to explain to me exactly how the system worked and although I understood very little of what he said 🤔, it did stand out to me that he stressed you can’t charge lithium batteries from your vehicle’s alternator like you would regular rv batteries.

Anyway, maybe check these guys out?
 

1cambo

Member
I just recently met a guy boondocking who is working out of his customized camper, who had built, installed and configured his own LiOn battery system for working via computers while on the road for the next year. He even built his own batteries.

He patiently took time to (try) to explain to me exactly how the system worked and although I understood very little of what he said 🤔, it did stand out to me that he stressed you can’t charge lithium batteries from your vehicle’s alternator like you would regular rv batteries.

Anyway, maybe check these guys out?
One thing not talked about or addressed is the fact the engine pulley is much larger than the one used on the test motor so the alternator is driven faster than the engine there for cooled more.
 
From what I understand you can wire the alternator directly to your LifePO4 and you will get great bulk charging. Without a separate product you won't get absorption or float charge stages but if you have solar that should take care of that. Really only need an isolator to disconnect the "house" battery from the starter battery when the truck isn't running
 
Any DC to DC converter will reduce the amount of Amps the battery can receive unless you spend big bucks to get something that allows for 150a or so.
 

Peter_n_Margaret

Adventurer
he stressed you can’t charge lithium batteries from your vehicle’s alternator like you would regular rv batteries.
Just don't tell those who are doing it :)
Check the capability of the BMS, particularly with "drop in" lithiums (which I would avoid).
Li will accept almost any charge rate offered, so it is important that the alternator can actually deliver its actual output without overheating.
Also check the output voltage. 14.4V is typical and that is OK, but I would not want more. That can be fixed if necessary.
And switch off the charge when the Li is close to full.
Cheers,
Peter
OKA196 motorhome
 
Last edited:

Korey H

Well-known member
We used a li-bim combiner as referenced in this battle born article. We self built 840ah with eve cells.


It of course does not take full advantage of the alternator… as referenced above the concern is that the lithium will take all the energy the alternator can produce leading to an overheat. You can find a couple lithium specific alternators I believe.

One thing I do like about the li-bim is that I can reverse combine them and to jump start the rig from the habitat battery. Kinda cool since there’s way more juice plus solar in the habitat.

Essentially yes you can charge from the alternator but have to be aware and cautious about over taxing the alternator.

I’m certainly no pro but have enjoyed the process of learning in our self build battery and system. 840ah lithium, 1460w solar. Our build here in the forum under c5500 mobile command and on IG @wehartstravel

I learned so much from Will Prowse as well as Nate Yarborough @exploristlife (awesome inexpensive wire plans).


Sent from my iPhone using Tapatalk
 

carterd

Member
Some good info in this thread. A battery to battery charger (Redarc, Sterling) is probably in order.

 
Last edited:
Top