Charging Lithiums in Parallel

[Meadows]

I posted this in the Electronics page but I know it doesn't get near as much activity as the lounge.....


I'm looking to get (2) 12V 125AH Ionics to run in parallel for my cranking/electronics and (2) 36V 50AH Li-Time batteries to run in parallel for my trolling motor.

I understand that I would ONLY need a two bank charger for this application. However, most of the 12/36V lithium capable chargers I see are only 10 amps per bank. Would this sufficiently charge the batteries since each battery would theoretically only be getting 5 amps each? Wouldn't it overheat the charger and take much longer for the batteries to charge?

Also, does anyone know of an on-board charger that provides more than 10 amps per bank in a 12/36V setup?

Thanks

[SteezMacQueen]

Yes it will work. I have two 125 Ionics paralleled for the main battery and one bank of a MinnKota 460PCL charging both batteries . Works great.

[Meadows]

Yes it will work. I have two 125 Ionics paralleled for the main battery and one bank of a MinnKota 460PCL charging both batteries . Works great.

How many amps per bank is that charger?

[dean c]

I know it’s not what you asked, and of course do what you want, but I think 2 125AH is serious overkill. 125AH will handle 4 graphs, scope, anchors, pumps, lights, starts, very well. I have a 160AH running all that and never seem to use more than 40-50 percent of the battery.

If you go with 2…maybe a Victron 15 amp as a separate charger. You can leave the quick connects on the battery and it’s a great little charger with a cool app.

https://www.amazon.com/Victron-Energ...1981319&sr=8-3

[I fish 4 Bass]

Try this. A board sponsor here sells these.

https://www.monstermarinelithium.com...rge-on-the-run

[Rich1]

Two 125ah batteries to 1 10a charger assuming the batteries are 75 percent discharged would take 19.5 hours to charge.

[Mcjenson]

https://powerhouselithium.com/produc...mart-charger-1

This is another option. A high power 35 amp single bank charger, and you can also pair it with their run and gun chargers to even charge the trolling batteries with it. Also can separate the 2 12V batteries so that one is electronics, one is for the motor and use another run and gun between the 2 12V batteries.

[DoctorJJ]

Two 125’s is not necessarily overkill depending on your setup. With 5 graphs (2 of which are 16”), 3 FFS units, a S3100 module, plus all the normal stuff on a bass boat, I needed 2 in parallel. Yes, one would work for most days but that 12+ hour overnight tournament where you catch one right off the bat and run your livewell all night, it would be dead. I love having 2 plus the 115 amp upgraded alternator on my Mercury, I have power for days.

[22RangerZ520R]

I have two 125ah Ionics parallel for cranking and electronics with the MK-550 5 bank charger. I have power hungry Apex units and I can go two full days without charging.

As mentioned above, just having one bank to try and charge both batteries would take a lot longer.

[SteezMacQueen]

How many amps per bank is that charger?

15

[78Staff]

I recently moved to two small Epoch chargers, one 12v for the 125ah and one 36v for dual 36v 60ah batteries, both 15amp chargers... Great setup, much lighter than my previous 3 bank Powerhouse and simpler to use, as I only need to charge the 36v's every 4-5 trips or so... They have disconnects so you can mount them in the boat or just plug them in when you need to charge. Give Andy at Drewcraft a call he can help sort you out...

https://drewcraftmarine.com/collecti...ttery-chargers

[Bill2e]

I run 2 each 100 AH Pro Guides and 2 each Pro Guide 50:AH 36 v for the TM

Both in parallel.

Charge with Power Pole Charge with no issues.