Dying Deep Cycle Battery 24 V

[captpierre]

I think one of my 12V trolling motor batteries is dead or on the way out.

 

This is their 7th season. The MinKota on-board charger says one is charged, the other one says "check connection".

 

I checked and the connection is good. The motor doesn't have the power it used to.

 

They are hooked up (series or parallel) to generate 24 V.

 

What is the best/easiest way to check their health?

 

If one is crapping out, should I replace both? I guess 7 yrs is all ya get

 

thanks, Peter

[vance]

7 years for a battery shows that you look after them,personally if they are the same age I would replace both of them just to save the aggravation of having another weak battery show up this year.

 

vance

[DRIFTER_016]

Check the fuse in the line from the charger to that battery.

Had one of mine pop this spring and that was the issue.

[lew]

The MinKota on-board charger says one is charged, the other one says "check connection".

 

My MinKota does the exact same thing if I have a very long day on the water and the batteries drop below a certain level. I then need to hook up a regular portable charger to bring them above the low level, then hook up the on-board again.

 

Pain in the neck because what good is an expensive charger if it won't charge low batteries. I called MinKota and was told that's a normal thing.

 

My last boat had a Guest charger and I never once had the problem and next year I think I'll go back to Guest again.

[Garnet]

You need a load tester. $49 from CTC.

 

Start with your battery's discharged.

 

Plug your charger in and immediately test both battery's. Your load tester should say 13.5 - 14-2 if it's lower than this your charger isn't working.

 

Let your battery's charge to full, now load test them. Fully charged should be 13.2 flip the switch. Just read the meter self explains.

 

The condition Lew describe happens frequently to lawn mower battery's. You can hook battery to a vehicle give them a blast.

 

7 years for any battery is a very long time. I would move on.

[Lape0019]

Simple solution would be to take the leads from the charger that is on the battery that is charged and place it the battery that says check connection. If the battery mysteriously charges, the fuse it probably shot. If not, you probably need a new battery but 7 years is awesome to get out of any battery.

 

I would replace them both at the same time. It will help to insure that your motor runs properly and you wouldn't get much more out of the other battery anyway.

[captpierre]

So, checked the fuse to the "bad'-check the connection" battery. 30 amp Buss fuse may be blown. (not in the middle but end of metal strip not attached)

 

Put a CT charger on that battery. Charger amp needle goes to full for 10 seconds then shuts off on own. The cycle repeats.

 

The same charger on the other battery charges nicely.

 

Sounds like battery is toast. Brought both home to take to my mechanic for assessment.

 

Thanks Guys for your comments. Will likely have to relace the one. Hoping not tp replace the other but after 7 yrs probably should.

 

Hate to part with the coin.

[DRIFTER_016]

Sounds like the battery may have boiled dry.

Need a new one.

[Roy]

You might also want to consider that a multi-bank charger will only charge to as much as the weakest battery in the group can take. That's why it's preferable to replace all batteries in the group at the same time. I once had to boost my starter battery with one of my TM batteries to get going. The only way I was able to get the TM batteries back up to equal status was to take the weak one off the onboard circuit and charge it separately...then put both on the onboard system.

[captpierre]

You might also want to consider that a multi-bank charger will only charge to as much as the weakest battery in the group can take. That's why it's preferable to replace all batteries in the group at the same time. I once had to boost my starter battery with one of my TM batteries to get going. The only way I was able to get the TM batteries back up to equal status was to take the weak one off the onboard circuit and charge it separately...then put both on the onboard system.

 

Thanks. Didn't know that.

 

better get 2--will try Costco