Deep Cycle Battery, Holding Charge?

Andyfender

Petty Officer 2nd Class
Joined
Oct 17, 2009
Messages
136
I have a 27 group deep cycle battery that I use for my trolling motor. It is roughly 4-5 years old. Two weeks ago it was fully charged at 12.43 volts. I have not used the boat in two weeks. I checked the battery tonight and the volts were 1.43. I also checked my starting battery and that was reading a full charge. Do I need a new deep cycle battery?

Thanks,

Andy
 

Brewman61

Ensign
Joined
Jun 10, 2010
Messages
996
Re: Deep Cycle Battery, Holding Charge?

Possibly. 5 years isn't too bad for a heavily used battery.
Any chance it's hooked up to something that may have drained it?
 

NYBo

Admiral
Joined
Oct 23, 2008
Messages
7,107
Re: Deep Cycle Battery, Holding Charge?

If it's only hooked to the trolling motor, it's a goner, unless your trolling has something drawing power when not in use.
 

Stachi

Lieutenant Commander
Joined
Jul 14, 2009
Messages
1,671
Re: Deep Cycle Battery, Holding Charge?

less than 2 volts...that girl is dead...find your parasitic drain , if you have one , and replace the old girl...best way to find a drain... remove negative battery cable, attach one lead of a voltmeter to the negative post on battery , the other lead to the negative battery cable , set the volt/ohm meter to dc volts, key in off position, and see what it reads...digital meter is best for this...if it reads 0 , you have no parasitic drain... if it reads anything above zero, pull one fuse at a time and check the meter...when you find the fuse that returns the meter to zero,the circuit that is fed by that fuse is your culprit... disconnect anything in that circuit , one at a time and check the meter until you find what is causing the drain.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,588
Re: Deep Cycle Battery, Holding Charge?

less than 2 volts...that girl is dead...find your parasitic drain , if you have one , and replace the old girl...best way to find a drain... remove negative battery cable, attach one lead of a voltmeter to the negative post on battery , the other lead to the negative battery cable , set the volt/ohm meter to dc volts, key in off position, and see what it reads...digital meter is best for this...if it reads 0 , you have no parasitic drain... if it reads anything above zero, pull one fuse at a time and check the meter...when you find the fuse that returns the meter to zero,the circuit that is fed by that fuse is your culprit... disconnect anything in that circuit , one at a time and check the meter until you find what is causing the drain.
Curious..why wouldn't you put it on the current measurement and actually measure the current draw. If its a few milliamps, you really don't need to worry about it but it will fail your test.
 

Barnacle_Bill

Admiral
Joined
Feb 8, 2004
Messages
6,469
Re: Deep Cycle Battery, Holding Charge?

4-5 years is a long time for a deep cycle battery. I would be willing to bet it would flunk a load test.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,588
Re: Deep Cycle Battery, Holding Charge?

If the battery was even 1 year old but deeply discharged a lot or not kept fully charged it could be failing. A lot depends on how the battery was cared for. I agree...do a load test on the battery. That is the best way to determine its condition.
 

E_Man

Petty Officer 2nd Class
Joined
Jun 12, 2006
Messages
127
Re: Deep Cycle Battery, Holding Charge?

I've got a Kirkland Costco battery that is in practically in new condition (besides the age) from 2006 that also doesn't seem to hold a charge. It has been stored in the garage every day and its always over 20 degrees Celsius.

I'm trying to figure out if my generator on the motor (Johnson RDS-25D) isn't recharging it or its the battery itself. I even had it refilled with the appropriate acid at Canadian Tire. I'm very knowledgeable with electronics but I don't know where/what to check. Anyone have an idea?

Thanks.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,588
Re: Deep Cycle Battery, Holding Charge?

Did you keep it fully charged while storing? How many times did you completely dishcharge the battery?
 

E_Man

Petty Officer 2nd Class
Joined
Jun 12, 2006
Messages
127
Re: Deep Cycle Battery, Holding Charge?

I believe it was always charged when stored, but you never know if I forgot the sonar on here and there. Again, I'd like to perform some sort of a test to see if its the generator or battery...

Did you keep it fully charged while storing? How many times did you completely dishcharge the battery?
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,588
Re: Deep Cycle Battery, Holding Charge?

Charge it fully. Take off the charger, wait 30 minutes, and measure the voltage. Should be around 12.6V if fully charged. Then either load test it yourself or take it somewhere to load test it.
 

Andyfender

Petty Officer 2nd Class
Joined
Oct 17, 2009
Messages
136
Re: Deep Cycle Battery, Holding Charge?

I took it to the auto parts store where the battery has been charging. When the battery reaches full charge they will test it out.

Andy
 
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