Any charging experts?

[upnorth]

The charger in our RV is just non quite fully charging our batteries. It does work, but I just noticed this year that when I pulled the batteries(the RV was plugged in to street power) getting ready to store it for the season, I put the batteries on the bench and hooked them up to the charger and found that both of them pretty much only had a 80% charge. And that was after a week or so of being plugged in. So yeah the RV charging system is working, but it would seem that it may not be charging them fully.

I know there are the typical, clean the connections etc, but as it is in storage that is no a happening thing right now. Could the charging system be weak or maybe just not set up to fully charge a couple of big deep cycle batteries.

Any ideas?

[jentz]

Did you test the battery with a volt tester?How'd you come to the 80% charged? 12.75V fully charged 12.3V 50% charge 11.90V total discharge.

[leech~~]

Are the batteries sealed or could you check them with a Hydrometer to see if you have any bad cells.

[upnorth]

Did you test the battery with a volt tester?How'd you come to the 80% charged? 12.75V fully charged 12.3V 50% charge 11.90V total discharge.

The battery charger I have give me a readout of the percentage of charge is where I got the 80% reading. I think the voltage reaout was about 12.5 volts, but not sure about that.

It did take about 12 hours to completely charge and that was both batteries not just one, so a low cell on both would be a large coincidence, but not impossible.

Just went out and checked both batteries after being fully charged on the bench charger and they are both reading 12.8 volts.

[jmd1]

actually a fully charged battery is 12.6666 volts. This is found by taking 2.10 volts per cell x 6 cells. You need to also load test these batteries, just because they charged up does not mean they won't hold the load. If you can take them to a shop etc that will load them for you, that will give you a true reading on your batteries. Even tho they are at 12.8 once that surface charge is gone they may crash out. Good luck

[Big Dave2]

How old are the batteries?