Triple Bank Charger

[arnettjs]

All,
I have a 1992 Cajun with a Johnson 115. All has been running well until yesterday. After fishing a good 5 hours, trolling around, the outboard wouldn't start. It was obviously a dead battery and I don't believe I left anything on (other than the two fish finders). There are three batteries (2 12-volt for the trolling, one 12-volt for cranking). It also has a Cabelas ProSport 12/24/36 triple bank charger.

I just put a voltmeter on the batteries w/o the outboard running. I have roughly 11.3 on all three. I topped off the cells (they weren't very low) and checked all connections. Plugging in the charger, the two trolling motor batteries jumped up to 12.5 and the cranking to 13.06.

I'm going to check them with the outboard running on ears but my question is this: How long do you (generally) leave the batteries on plugged in on that charger. I am sure there are a number of factors (such as age of battery, discharge state, etc.) but I've been keeping it plugged in for about 90 minutes or so. I'm thinking this isn't long enough. Note that my lake is small and I don't run the outboard very long (thus it probably doesn't charge the batteries much).

Sorry for the long post, wanted to give as much info as possible.

Thanks y'all!
Jeff

 

[Silvertip]

Re: Triple Bank Charger

90 minutes is not long enough to charge a battery -- any battery. On board chargers are designed to be plugged in and left on. Look at it this way. If your trolling motor draws 50 amps and you ran it wide open for 3 hours it would have consumed 150 amps worth of juice. If your charger is rated at 20 amps/bank you would need to have it connected for nearly 8 hours to top them off. You are killing your batteries. Plug it in when you get to the dock (or home) and leave it connected. Leaving batteries in a discharged state will kill them.

 

[arnettjs]

Re: Triple Bank Charger

OK, I completely understand that. However, I am concerned about draining the water in the cells. I used to leave it on full-time, like you are saying, but I remember the cells in all the batteries running almost bone dry. Suggestions?

Thank you very much!

 

[Silvertip]

Re: Triple Bank Charger

Then you may have a malfunctioning charger. What brand, model and how old? Fact is, you cannot replace 150 amps of power in 90 minutes with an on board charger. And how old are the batteries? You should have the starting battery load tested. Actually it would be good to have all three tested. Just because you charged them does not mean they "hold" a charge. 11.3 volts on a battery is nearly stone cold dead. Measuring voltage with the charger attached merely indicates the charger is supplying power. It has nothing to do with the condition of the battery. That's what load testing does -- it tests the battery under a heavy load.

 

[arnettjs]

Re: Triple Bank Charger

Great information, thank you very much. I have had the triple bank plugged in for 4 hours now and the batteries are 'leaking' a bit through the vent caps. That being said, I did fill a few of the cells up a bit much. I'm going to let it charge over night and see if the Cabelas ProSport 20 flashes "ready"....one of the lights on the panel. The charger is fairly new, though I didn't put it on (probably 2 years old tops). Agree completely on the length of time to put on the charger, makes absolute sense to me.

Thank you again, much appreciated.

 

[Splat]

Re: Triple Bank Charger

Some boiling over may be normal in the instance. THe charger is really going to kick the hell out of the batteries at or near it's max output to get them back to normal operating voltage. It may even be in a de sulfication mode.

HOWEVER boiling to the point where the plates are becoming uncovered will ruin the batteries, and signifies a problem with the charger.

Bill

 

[arnettjs]

Re: Triple Bank Charger

Very helpful information, thank you. One more thing: When I leave it plugged in for x hours (say 8), the charger gets really warm. Is this normal? Also, its my understanding that these chargers can be used for three different battery types. Is there a way to check/set for the appropriate type?

Thanks again,
Jeff

 

[rndn]

Re: Triple Bank Charger

The charger will get warm when being used. Just make sure you have it mounted so you have air flow all of the way around it. My Bass Pro 3 bank charger will charge gel or lead acid, not both. There is a jumper to be installed when charging gel batteries.
If by 3 types of batteries you mean starting, deep cycle, or combo, then yes most on board chargers will charge these 3 types at the same time.
I have left my on board charger plugged in for weeks on end without any water loss from the batteries.

 

[arnettjs]

Re: Triple Bank Charger

The airflow sounds like something I'm definitely doing wrong. My charger is mounted inside my battery compartment under the back deck (with the three batteries). It is mounted vertically, I believe that is correct. I am guessing that I need to open up the back deck so that I allow airflow. To this point, I have not been doing that, simply pulling out the pigtail and hooking up while leaving the battery compartment completely closed. When doing this, it does get very hot, both on the charger and inside the compartment itself.

 

[arnettjs]

Re: Triple Bank Charger

Just to close the loop, thank you for all the information. I raised up the back deck to allow plenty of airflow through the battery compartment, plugged in the 3-bank charger and let it run all night. Came back the next morning and found the blue "Ready" light on and all seems good. Much appreciation, glad I don't have to buy a new charger.

Thanks again,
Jeff