How do you charge SLA batteries?

[kramynot2000]

I'm in the midst of building a cannister light (with lots of help from PadiPro's files!) and I'm not sure how to go about charging the batteries. I tried Scott's method of stretching a 4" PVC pipe so I could fit 12v7ah batteries in it but really had no success. So, I opted for two 6v7ah batteries that I'll hook up in Series to get my 12 v. These fit perfectly in a 4" pipe.

Because these are sealed acid batteries, I was thinking I could just use the trickle charger that I have for my motorcycle batteries. Would that work? Also, can I keep the batteries hooked in series and then charge at 12v?

Thanks for all the help and all the information contained in the threads. They've really helped me along.

Tony
Sacramento

[pcscuba]

Go to you local auto parts store and get one of there shumaker chargers. There are several different types. I can't remember what the part # is but it was the smallest one they had and on the package said it was great for SLA batteries. I think it was about $25.00. I've used mine for a couple of months and it works great. It is designed to not overcharge your battery and just maintain a charge.

[kavka]

I use 4 batteries 6V,4Ah. That gives me 12v,8Ah and I'm charging them with normal car accu charger.

[nickjb]

Car battery chargers can damage SLAs. They aren't very well regulated. For charging SLAs you want a very constant voltage for optimum life.

A trickle charger should be OK but it will take a while to charge a 7Ah battery (15 to 16 hours if done properly). A model shop or electronics shop should have dedicated SLA chargers that will do a better job.

You can connect SLAs in series just fine if they are the same size (as yours are)

[j-valve]

Go to your local computer recylcers and find an AC-DC that is 12V and rated for your amperage by the manufacturer. On most manufacturer web sites they give max charging current, find it in the pile at the recyclers and cut the connector to suit.

J

[kramynot2000]

Thanks for the tips guys.

[kmorley]

The Airspeed book has a whole chapter on battery chargers and charging but it recommends for cheap the Shumaker maintenanace charger, the one thats made so you can screw it to the firewall of a car, and if you want to get the most out of the batteries the Deltran.

Don't try to make your own or improvise AGM batteries are fussy. Both the above chargers are smart chargers so they automatically switch off or into a trickle phase to avoid overcharging.