On board charger

[WallyGader]

Just found out my on board charger only charges one battery now after storage. Anyone have some insight before I just buy one, looking at just a 2 bank 5 amp or 10 amp per bank charge. Any reasoning to get one over the other? Running a 24v 80lb minnkota.

[Nastynate]

The Pro Mariner's seem to be the best. Just remember you need 10amps minimum per deep cycle battery. So at least a 10amp per bank charger.

[gunner55]

I agree 2/10 charger minimum & there are a few brands with good reviews.We have a 2/10 MK that's been on our boat for 6 or 7 yrs.If you want to save a little $ checkout the rebuilt Dual Pro's at Pro fishing Supply

[h8go4s]

Are you sure it's the charger and not the battery? Most onboard chargers won't charge a really low battery, you have to charge it up with a regular automotive charger first. But if it's that dead you might need a new battery.

[WallyGader]

Thanks for the input, will try charging battery up and seeing if that works. Otherwise I will look into the pro mariners.

[chris63]

Explain your theory of onboard charger won't charge a "low"battery,please.c63

[Hawg]

I was always told that you take the amp rating of your battery and divide it by the amps your charger does and that is the number of hours to charge from dead to full. That's right isn't it, within reason anyway? I sure wouldn't buy less than 10 amp charger, the price isn't that much different.

[h8go4s]

Explain your theory of onboard charger won't charge a "low"battery,please.c63

It's not my theory. It's a fact. Here's a quote from the DualPro troubleshooting page:

"Q: When I plug my PCS charger in to begin charging my batteries, the red lights will not turn on but the unit has a slight hum to it. It has been a long time since I last used the charger. Is there a problem with the charger or my batteries?

A: No, if batteries are left for extended periods of time without being charged, the voltage of the batteries will continually fall. If your PCS charger observes abnormally low voltage on one or all of your batteries, it will not allow itself to charge until the voltage is raised by another means. The easiest way to do this is by using a basic manual charger for a short amount of time while leaving PCS charger connected to the batteries and plugged in."

Here's the source:

http://www.dualpro.com/support/faq-troubleshooting/

[Hawg]

But that would only happen if you left a load on them for the winter without a maintainer of any kind wouldn't it? I've run my batteries pretty darn dead and the on board has always worked. I can see where a battery that's been dead and frozen all winter would need a shock to wake it up but it's probably beyond help at that point. That sounds more like a disclaimer than a real scenario but if a person is that careless they shouldn't own anything with a motor anyway. I bought a 3 bank ProMariner from Fleet for a lot less than the worthless piece of ____ I had that was from Minn Kota. Dual Pro is a great one too.

[BobT]

The internal circuitry of the charger is probably designed to detect a defective battery and using the battery's output voltage may be one way of doing this. If the voltage is too low, it might be thinking the battery is shot and therefore it won't output a charge to protect itself from overload.

[delcecchi]

short circuit protection for the charger.

[Gorby]

But that would only happen if you left a load on them for the winter without a maintainer of any kind wouldn't it? I've run my batteries pretty darn dead and the on board has always worked. I can see where a battery that's been dead and frozen all winter would need a shock to wake it up but it's probably beyond help at that point. That sounds more like a disclaimer than a real scenario but if a person is that careless they shouldn't own anything with a motor anyway. I bought a 3 bank ProMariner from Fleet for a lot less than the worthless piece of ____ I had that was from Minn Kota. Dual Pro is a great one too.

​I have had this happen its not that hard to do. you use your boat late season to the last minute. Bring it to storage quick to try and beat the salt on the roads and you forget to put the charger on. in a non heated storage unit batteries will take a beating in the winter. when you have a busy life it will happen, but a good jump with a car battery charger and it will wake it from its slumber.