# Onboard charger and deep cycle batteries



## lemaymiami (Feb 9, 2007)

You might want to do a bit of research about on board chargers that "five amp charger" might have contributed to the death of the batts you have... For my 24volt installation we went with two wet cells - group 27 batteries along with a PowerMania 10 amp charger. I couldn't be happier (and should have done it long ago...).

Hope this helps... Aren't boats fun?


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## Lowtidelowlife (Aug 19, 2014)

Promariner 20 has always done me solid. I know there’s smaller tenders out there. But this one has been an idiot proof system.


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## RABillstein (Jan 10, 2019)

I was hoping to keep the charger, and find two batteries that work well with it. Both of y'all recommend a new charger. Can you please elaborate why the Minn Kota MK-210D won't suffice for flooded lead acid batteries?


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## jay.bush1434 (Dec 27, 2014)

I'm not sure where you read that Odyssey batteries needed a 15 amp charger. Odyssey sells a 6 amp charger for their batteries. Only difference between the 6 amp and the 12 amp charger is how long it takes to recharge the batteries. Lead acid batteries are the least picky when it comes recharging.
My best guess, other than the age of the batteries, is that you have 2 different size batteries hooked up to the same charger. If this is the case, your charger probably overcharged the group 24 battery and caused one or more of the cells to short out. A 27 will take longer to fully recharge than a 24, the chargers detect the charge level and will keep charging until the charge level comes up.
You'll be fine with 2 PC 1200's and your current charger.


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## RABillstein (Jan 10, 2019)

@jay.bush1434 Thanks for the reply. I heard about the issue of low amperage with the PC1200s on a few different forums. I then dug deeper on the Odyssey website and found their literature that recommend at least 15amps for the PC1200s. I have read that the issue with lower than recommended amperage with AGMs is sulfation. The sulfation, which will occur with repeated low amperage chargings contributes to reduced capacity and an early death of the battery.


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## firecat1981 (Nov 27, 2007)

Does your onboard charger have a conditioning and maintenance cycle. If so then don't worry about it.


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## RABillstein (Jan 10, 2019)

@firecat1981 It does. Don't worry about what specifically?


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## firecat1981 (Nov 27, 2007)

It will do the job just fine.


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## jay.bush1434 (Dec 27, 2014)

What I learned from having PC1200's on my boat (3 of them) and reading on the Odyssey website, is that the batteries don't like to be partially discharged and then discharged more without a full recharging. It will shorten their life. 
I have a Powermainia onboard charger for my trolling motor batteries and then just use the engine alternator output to recharge the house/start battery.


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## lemaymiami (Feb 9, 2007)

That's how I'm set up with one additional small item... One of my troller batteries is also hooked into the battery switch that my starting battery is on (the way it was before we added that third battery to go to a 24 volt power source for the trolling motor). That way if my starting batt isn't properly charged I can combine the two batts (the group 27 and the group 24 starting battery) for a quick start then turn the switch back so that the starting batt is a stand alone again... 

What I didn't know was that although my two group 27's were combined to produce 24 volts - you could still pull power off of either one of them - and it would be at only 12 volts inspite of them being hooked together... Who knew?


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