Charging 2 batteries in parallel

[Amac88]

For those that have been running 2 cranking batteries in parallel. What is your preferred charge method, same bank or separate?

[bassfisher444]

You shouldn't have 2 cranking batteries in parallel.

[Amac88]

You shouldn't have 2 cranking batteries in parallel.

Clarification, dual purpose. Cranking and running graphs, livewells, etc.

[bassfisher444]

The outboard motor should only be hooked to one battery.

[Amac88]

The outboard motor should only be hooked to one battery.

Thanks, I see this setup commonly done? Just wasn't sure how many were charging the battery, wanted to get a census.

[TXZ21]

Maybe I shouldn't be doing it, but I have been running this set up for a little over a year now with no issues. 2 Ionic 125ah paralleled running everything, and cranking. Using a MK 550PCL 5 bank charger. 1 bank each for the 125ah Ionics, and 1 bank each for the 3 50ah TM batteries. Works great.

[Meleagris1]

Lots of guys running like this for many years now - I ran two ionic 125s in parallel on my PHX and used one bank on my MK460PC to charge them. I also had a quick connect on them so I could piggyback chargers if they were low - if below 50% they could take a while on one bank. On my current boat I’m running two Millertech 190ah in parallel for 380ah total with an on board Millertech 12/36 2 bank charger to them and quick connect for a second charger if needed.

[walleye3456]

Two ionics in parallel, charger hooked to positive of one battery and negative of other. It takes some time to charge when they are low but they always are full by the next day.

[Coke]

The outboard motor should only be hooked to one battery.

If the 2 batteries are hooked up in parallel (not in series), it is still only a 12v system, but will be able to provide power for a longer time.

[bassfisher444]

If the 2 batteries are hooked up in parallel (not in series), it is still only a 12v system, but will be able to provide power for a longer time.

Correct, but Mercury doesn't recommend doing that with their motors.

[Rick McFaul]

I run (2) X2 AGMS in parallel and (2) 36V Lithiums in parallel. They are all connected to the Power Pole Charge. This system works great and there is duplicity just in case one of the batteries has an issue.

[ThomasD]

Correct, but Mercury doesn't recommend doing that with their motors.

Mercury didn't recommend Lithiums either until their parent company Brunswick bought a lithium battery company.

[CHECrappie]

I run (2) X2 AGMS in parallel and (2) 36V Lithiums in parallel. They are all connected to the Power Pole Charge. This system works great and there is duplicity just in case one of the batteries has an issue.

Same here. I have a 100 AH lithium start with another 50 amp lithium parallel. Power pole Charge charges them great.