alisasings Report post Posted May 12, 2012 We drove 250 miles yesterday on our maiden voyage & towards the end a strange smell started filling the RV. Father n law said that the battery was starting to boil because the alternator was overcharging it & that we should run with the headlights on and that will take care of the issue. Any thoughts?? Share this post Link to post Share on other sites
wolfe10 Report post Posted May 12, 2012 A boiling battery could be cause by a bad battery OR too much voltage. Either will cause the same symptoms. As an example, if one cell in the battery is bad, you alternator (functioning perfectly) could try to charge 5 cells (instead of 6) at 14 VDC. That WILL boil the batteries. So, first thing to do is to check the batteries when fully charged with a hydrometer (under $10 at any auto parts house). The other thing you can/need to do is check voltage at the battery with the engine running and at high idle. Should be 13.5-14.2 VDC. If you don't have a digital voltmeter, get one. They start under $20 at Radio Shack, Sears, etc and are invaluable in diagnosing electical issues on RV's. Share this post Link to post Share on other sites
alisasings Report post Posted May 12, 2012 Thanks. I know the battery is 3 years old. Maybe we'll get a new one. We replaced the batteries that the generator charges, should've done the same with this one. We'll pick up the testers. Share this post Link to post Share on other sites
