Battery being overcharged?

[mtnwkr]

I walked out to the garage and noticed my schumacher sc-1200a charger was reading 99% charged at 16v on the LCD. I grabbed my multimeter and the battery was reading the same. I unplugged the charger and checked the battery again in a few minutes and it was reading 13.4v. Is this normal for the charger to reach 16v at the end of its charging cycle? It's a new 29 series deep cycle and the "smart" charger is a few years old. Hope I'm not frying the battery.

 

[earl60446]

It's probably ok. You can contact schumacher thru their website and ask questions of them. I did it once, took a couple days to return the email.
Tim

 

[JMichael]

16v does seem a bit high. I can't say that I've seen it in print anywhere as to how high the max voltage of a charger should be but I was thinking around 14v. Contact the mfg like earl suggested and see what they have to say. If you can remove the cell caps on your battery, you might also want to keep an eye on the acid levels for a while. One thing that will certainly happen if it is overcharging, the acid levels in all cells will start to drop.

 

[earl60446]

I also have a schumacher charger, it is a max 15amp, 3amp slow charge. I hooked it up today and monitored it. It ran about 13.5volt until it hit 98%, then it went up to 15.9volt quickly. Same way whether it was at 15amp or 3amp rate. Probably circuitry in the charger goes into some kind of maintain mode at 98% and cuts the current level. JFYI
Tim

 

[mtnwkr]

Got a reply from the manufacture. They said it must have detected sulfacation and gone into desulfacation mode. Well, This is a brand new battery and has done this the 3 times I've charged it.
I'll be buying a Minn Kota charger.