Battery pooched or charger not working correctly ?

Rob V

Rob V

Well-Known Member
I think my deep cycle trolling motor batteries have reached the end of their useful life (they’re 6 years old) and need to be replaced. With that said I would like to make sure my onboard two bank charger is working properly (it’s 10+/- years old too). What’s the easiest way to determine if my battery charger is doing it’s job properly/sufficiently ? Thanks in advance.
 
Your best bet is to hook up the charger and test the voltage across the battery posts with a digital volt meter set to DC volts, check both while charging and while off.
Fully charged to 100% and after allowing it to rest for 5-10mins with the charger off a good battery should read 12.6V and anything less then that after sitting for a bit would indicate the battery isn't getting fully charged or is getting weak.

With the charger turned on and actively charging you should see 14v to 14.7v across the battery posts of each battery being charged in your system. If you're getting 14+ volts charging then most likely the batteries are done. 6 years is pretty good life span from them depending how often you fish in a season. Its not so much age but how many times they've been deep cycled to below 50%. The more times they get down below 50% the faster they'll loose their capacity.
 
RJMP said:
Your best bet is to hook up the charger and test the voltage across the battery posts with a digital volt meter set to DC volts, check both while charging and while off.
Fully charged to 100% and after allowing it to rest for 5-10mins with the charger off a good battery should read 12.6V and anything less then that after sitting for a bit would indicate the battery isn't getting fully charged or is getting weak.

With the charger turned on and actively charging you should see 14v to 14.7v across the battery posts of each battery being charged in your system. If you're getting 14+ volts charging then most likely the batteries are done. 6 years is pretty good life span from them depending how often you fish in a season. Its not so much age but how many times they've been deep cycled to below 50%. The more times they get down below 50% the faster they'll loose their capacity.
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Thanks for the excellent info RJMP. I checked the voltage across the batteries with the charger working and I’m getting about 12.5 volts, which sounds like my charger may be dyeing ? How long can you expect a charger to last. Mines got to be 10 -12 years old now and I use it regularly during the season but not during the winter. It’s a GUEST charger which I understood to be a decent unit.
 
Rob V you're very welcome. Sounds like the charger may be the issue after all as 12.5 isn't even enough to push a charge into the cells. If you can borrow or try a different charger first it might save you having to change out the batteries this year. While I'm not familiar with that particular charger they do often fail over time like anything else electronic. It is however still possible for a bad battery to show low voltage while charging if they have issues internally so unfortunately the batteries can't be ruled out completely just yet. You can also try charging one battery separately with an automotive type battery charger to see if the voltage comes up under charging, if it does and afterwards holds steady at 12.6v after the charge finishes then that could help determine weak battery vs bad charger as well.
 
The batteries need to be tested correctly before you condemn the charger. A sulfated or shorted battery will not allow the charger to charge to its regulated output. Check the charger output in volts while hooked to a battery that is known to be good and checks out to have a soc ( state of charge) of 12.7V to no less than 12.2V at rest. This will allow the charger to reach its potential output of 14.5v respectively.
The batteries in question should have the specific gravity tested with a hydrometer. A sealed battery cannot be tested, however if you can remove the cell caps each cell of a charged battery should have a sg of 1.28 and no less than 1.22. If the sg is in range that means the battery is not sulfated or at least not bad. Now it needs to be load tested. A load test will determine the amperage the battery has in storage and is capable of putting out. If a battery does not pass these tests it is junk and your charger may not have been capable of its potential. If you are unclear of performing these tests go to a jobber or Canadian tire. They generally have the needed test equipment for battery warranty purposes.
A good quality lead acid batteries life expectancy is not any more than you have gotten out of yours. Pounding around in a boat, poor quality batteries such as interstate, ever ready (walmart) and such, tend to break the lead plates loose.
Good quality batteries such as east Penn, napa, or Trogan are built to a higher construction standard and will take much more of a beating and contain much more lead. A good AGM (a glass mat) battery such as optima is even better but very pricy. The lead is wrapped in fiberglass and the acid is held by the fiberglass.
In any way shape or form good batteries, proper charging and maintenance is worth it. When In question proper testing will give you the answers needed to make an informed decision. Hope this helps.
 
@Letsfish , do you have a few hours to spend with my '06 Dodge Caravan?:D. There are a growing number of lights on the dash which are a worry.
 
Letsfish said:
The batteries need to be tested correctly before you condemn the charger. A sulfated or shorted battery will not allow the charger to charge to its regulated output. Check the charger output in volts while hooked to a battery that is known to be good and checks out to have a soc ( state of charge) of 12.7V to no less than 12.2V at rest. This will allow the charger to reach its potential output of 14.5v respectively.
The batteries in question should have the specific gravity tested with a hydrometer. A sealed battery cannot be tested, however if you can remove the cell caps each cell of a charged battery should have a sg of 1.28 and no less than 1.22. If the sg is in range that means the battery is not sulfated or at least not bad. Now it needs to be load tested. A load test will determine the amperage the battery has in storage and is capable of putting out. If a battery does not pass these tests it is junk and your charger may not have been capable of its potential. If you are unclear of performing these tests go to a jobber or Canadian tire. They generally have the needed test equipment for battery warranty purposes.
A good quality lead acid batteries life expectancy is not any more than you have gotten out of yours. Pounding around in a boat, poor quality batteries such as interstate, ever ready (walmart) and such, tend to break the lead plates loose.
Good quality batteries such as east Penn, napa, or Trogan are built to a higher construction standard and will take much more of a beating and contain much more lead. A good AGM (a glass mat) battery such as optima is even better but very pricy. The lead is wrapped in fiberglass and the acid is held by the fiberglass.
In any way shape or form good batteries, proper charging and maintenance is worth it. When In question proper testing will give you the answers needed to make an informed decision. Hope this helps.
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Thanks for the great info. I discovered that one of the in line fuses on one of the leads on my charger was blown. Problem 1 addressed. Now I’m trying to charge the batteries and the charger won’t finish them off. So It would be my guess the batteries are either at or near the end of their useful life and I”m going to get them tested.
 
Rob V said:
Thanks for the great info. I discovered that one of the in line fuses on one of the leads on my charger was blown. Problem 1 addressed. Now I’m trying to charge the batteries and the charger won’t finish them off. So It would be my guess the batteries are either at or near the end of their useful life and I”m going to get them tested.
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6 years is a good go for any battery. I would just go new. Carquest sells delco but branded carquest. Napa sells eat Penn branded Napa. Napa would be my first choice because trogan and optima are very pricey.
 
the batteries i have are DeKa’s and obviously I’m happy with the life I got out of them. They’re made by East Penn also I believe and come with a 24 month non-prorated replacement warranty. A couple bucks more than the Napa but a better warranty than NAPA offered according to the person i spoke with there over the phone.
 
Rob V said:
the batteries i have are DeKa’s and obviously I’m happy with the life I got out of them. They’re made by East Penn also I believe and come with a 24 month non-prorated replacement warranty. A couple bucks more than the Napa but a better warranty than NAPA offered according to the person i spoke with there over the phone.
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Absolutely. East Penn batteries are great. Go with the proven ones.
 
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