Charging LiFePO4 with your alternator
- Thread starter jcdostie
- Start date
iggi
Ian
12V 20A DC to DC On-Board Battery Charger
The best 12v battery charger. Free shipping. The DC-DC Battery Chargers are the most effective method to charge your home batteries from the starter battery
www.renogy.com
AbleGuy
Officious Intermeddler
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?
www.victronenergy.com
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?
Careful - Alternator Charging Lithium - Victron Energy
Charging lithium batteries from an alternator, be that in a boat or vehicle, presents some challenges when compared to the straightforward nature of charging lead based batteries. The video in this blog highlights these lithium challenges and shows you what can happen when things go wrong –...
www.victronenergy.com
Korey H
Well-known member
Check out the Will Prowse vids on YouTube and his associated website.
Sent from my iPhone using Tapatalk
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.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?
Careful - Alternator Charging Lithium - Victron Energy
Charging lithium batteries from an alternator, be that in a boat or vehicle, presents some challenges when compared to the straightforward nature of charging lead based batteries. The video in this blog highlights these lithium challenges and shows you what can happen when things go wrong –...
tmckenna13
Member
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
tmckenna13
Member
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
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
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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.
battlebornbatteries.com
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
Battery Isolator with Lithium and Lead Acid Connections
A Battery Isolator is vital when making the decision to tie your batteries together. Our team explains how to do this correctly.
battlebornbatteries.com
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
Some good info in this thread. A battery to battery charger (Redarc, Sterling) is probably in order.
expeditionportal.com
Second Alternator Charging Lithium Battery Bank
I'm hoping someone smarter than me (shouldn't be too hard to find!) can help me out. I'm looking at a 2021 Ford E450 chassis, with factory second alternator (157 amp/hr). I want to use the second alternator to charge 4X 100 amp/hr battleborn lithium batteries, which will have their own...
expeditionportal.com
Last edited:
jcdostie
Member
Now that I have finished the construction and run it for almost 3 years, you cannot hook directly to your alternator. I installed a DC-DC charger limites to 60Ah. Because the LiFePO4 batteries are like a black hole. They will absorb every current available (almost, depends on the BMS). So, when the truck is idling, the alternator will overheat. It tries to deliver the max Ah possible.
JC
JC
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