battery charging

[snake21]

hi friends,i have a 100a\h sealed deep cycle battery which i bought to set up my small 12v system.i have kept that for about 3 month and now the voltage has dropped to 12.75v.i really need to charge that manually.can someone tell me how to do that please.please provide me with a diy solution

thanks

[zap]

I wouldn't worry too much at 12.75v even though it's nice to see them sit at 13.2v

Do you have a car with a 12v system?  If you don't have a 12v charger then that's an easy way to charge up the deep cycle battery.

Let the car take the battery up to 14v while you monitor it.  Don't let the car's charging system determine the finish voltage because it will probably be too high.
A 100ah deep cycle should be able to tolerate a little more than 14v but if you have the manufactures info on the battery then follow that for a charging voltage.

[wpowokal]

What source do you have for recharging the battery, 12.75 does not sound too low, best advise is to Google the battery makers to obtain charging details. sealed batteries are much less tolerant to excessive voltage than flooded batteries. Probably a simple auto battery charger will suffice if you watch the voltage.

allan

[snake21]

ok,i will have a look at the battery specs and post it as soon as possible.

thanks for replying friends

[ruddycrazy]

G'day Snake,
                  Have a look on the battery and see if there is a voltage per cell rating, any decent SLA will have one. The main problem with deep cycle SLA's is over voltage which will over time dryout the electrolyte and cause the battery to start to bulge on the sides. How do I know this, those 30 off 6 volt 110ah batteries I got from the scrapyard 6 years ago didn't like 28.8 volts put into them. I do run a 24 volt array too, later I found 27.58 volts was the float voltage and I'll bet yours will be around 13.7 or 13.8. go higher over long periods and you'll see your battery dryout and become a 60c a kilo scrap item.

Cheers Bryan