DC-DC charger overload tow vehicle alternator charging lithium batteries?

kottum

Could a DC-DC charger overload our 2021 Honda Ridgeline 155 watt alternator, charging our two 100ah Battle Born lithium batteries ?  Lower resistance than AGM or liquid cell batteries.

MarkAl

Depends on your charger. It will control charging the specific battery type and charge condition according to its rated limit.  155 watt alternator can probably output about 10 amps but that assumes nothing else in the car is pulling current - unlikely.  A 10 amp charger could be too much. I'd probably use one but worry. I have a much bigger one in my TV.

kottum

Kind of what I thought.  I better leave the Honda Ridgeline factory charge system alone, it should charge some but is limited by resistance of the long and small wire running from alternator to the Tab batteries.

WayneW

That’s probably a 155 amp, not watt, alternator which I think would handle something like a 20 or 30 amp dc-dc charger fine. You do have to run heavier gauge wire to/from the charger to get decent results. I used 8 gauge wire for my Renogy 20a dc-dc charger and it works great. My TV has a 115 amp stock alternator and it puts 20a to the charger at idle without any problems. 

Renogy has a limiting wire that you can hook up to cut output by half if you want. I have mine on a switch so I can choose what output I want, 10 or 20 amp.