Split charger 2 batteries

hi all. I’m fitting a split charger. The vehicle has 2 12v batteries, 1 for the engine and one for a disabled lift i have removed. they are wired together so i thought to use the live feed off the second battery which was going to the lift for the split relay. Does it matter that there’s 2 batteries? does that make it 24v? please any help appreciated

Hi Peter,
I am in a similar situation with my repurposed paratransport van: trying to unravel the riddle of the house battery. Does your house battery feed back to the engine or is it a “one way flow”?

hi nancy. I don’t know if it feeds back to the engine. I assume its the same as any other car battery system which is one way flow. I think the best route for me is to removethe second battery and do it as normal

what van do you have? mines a 2004 ford transit

I have a 2006 Ford E350 high top.

So much to learn, used be that this was my go-to site to begin to explain the batteries, https://cheaprvliving.com/kb/ . It’s changed & it’s not as simple to find the answers as it was but there are answers there. Lot’s of answers on the cheaprvliving youtube channel too.

I did a search on “hooking batteries in series vs parallel”… if you hook the two batteries “parallel”, (+ to +), you are keeping the same voltage and doubling the capacity.
If you hook them in “series”, (+ to -), you are doubling the voltage and keeping the same capacity of amp hours.

@peter_goodman If the vehicle has two batteries, and one is for the lift…it could be likely that there is already a split charger fitted to the vehicle which is designed to keep the lift battery separate from the starting circuit but still able to charge. In turn, it is unlikely that the starting battery will be connected to the lift circuit to prevent it discharging through use of the lift.