Deep cycle battery question

[Hooked]

Hi there, I have a deep cycle battery I was charging the other day. I have my charger set to 15A charge. The thing is the meter would go up to around 10amps, stay there for a minute then go to 0. This repeated itself over and over again. I left it and returned later to find that it was complete.

I put my multi-meter on it and read 13.01 Amps. Is this a regular output on a charged batter? Kinda thinking it might be toast with the fluctuation issue I witnessed while charing. This batter did give me some issues charging last summer too. It's not even 2 years old and has not been used all that much. Any input would be appreciated.

[Dutch]

The needle jumping around means the battery is fully charged, I think. That's what happens with some other chargers I have seen.

 

13 amp reading on a fully charged battery is normal.

 

If in doubt, take to a battery shop for a load test.

[Hooked]

The needle jumping around means the battery is fully charged, I think. That's what happens with some other chargers I have seen.

 

13 amp reading on a fully charged battery is normal.

 

If in doubt, take to a battery shop for a load test.

 

Thanks Dutch, I think I'll take it in for that test. It most definitely shouldn't of been fully charged, was sitting there for 3 months.

[Woodsman]

I take it you actually mean it was reading 13 volts after charging with the charger disconnected. A little on the low side.

Leave the battery for a couple days & then check out what voltage it's at.

If it's dropped from 13 volts to any major degree then it is not holding a charge. Battery is gone.

BTW: Deep cycle batteries are better being charged by a lower amp charger (ie: 2 amps) over a longer period of time.

[ecmilley]

it' volts your are checking 13 is fine for a deep cycle, before you take it in have you checked the water levels? very important if you have exposed plates and charged it may as well get a new one and if it's been sitting that long it may be ok but i suggest charging at 2 amps initially for several hours before bumping up the charging rate the bouncing needle on the charger is usually an indicater of a battery plate shorting out or verty low state of charge

[Hooked]

Thanks for the info guys.

[NANUK]

Sounds like the battery is fully charged but you can always double check

Let the battery sit for a few hours without the charger to remove any surface charge.

Check with a good DC volt meter and/or with a Hydrometer (Always wear face protection and away from any combustibles.

 

This is for Deep cycle batteries.

VOLT METER...........CHARGE....................HYDROMETER

12.65v ..................100% ....................1.265

12.45v .................. 75% ....................1.225

12.24v .................. 50% ....................1.190

12.06v .................. 25% ....................1.155

11.89V .................Discharged.................1.120

 

Make sure the water level is above the plates, preferably about 1/4" below the neck of fill hole.

You can also take it to a battery shop for a load test as mentioned above, most will test it for free .

[Tybo]

When using a hydrometer you should rinse it out after every cell check.This way gives you the most stable readings.

[RSF]

Hi all,

Here's another simple method to determine the charge of a 12 volt battery, personally, I let it sit for an hour or so after charging before taking a meter reading:

 

VoltageState of Charge12.6+100%12.5 90%12.4280%12.3270%12.2060%12.0650%11.9 40%11.7530%11.5820%11.3110%10.5 0%

 

Avoid discharging the battery below the 40% level whenever possible