battery overcharging

marler · Mar 9, 2012

I have a LK2554. I am getting 17.5 volts while the tractor is charging. I just replaced the alternator. Still getting 17.5 volts or better. Where else can I check?

SSdoxie · Mar 9, 2012

If the battery has a shorted cell it can cause an excess voltage draw so alternator would be put out extra volts trying to keep up.

murphy1244 · Mar 9, 2012

What is the battery voltage while the tractor is off?

JimRB · Mar 9, 2012

I had to jump my tractor. This was a few years ago but seem to recall that the charging voltage was way high. New battery and the charging voltage was fine. I would not put a new alternator on without having the old one bench tested. Way too much money to toss around.

marler · Mar 10, 2012

I just put my 2nd battery in two years in. The Alternator is brand new. I am getting 13.3 volts with the tractor off

Traxx · Mar 10, 2012

Most battery chargers now have a battery and alt test mode. I would look into one before a battery or alt. They are much cheaper and can be used on about any thing.
17volts does seem a little high. Should be more like 14/15volts.

marler · Mar 10, 2012

no more ideas?

murphy1244 · Mar 10, 2012

If your measuring voltage at the battery you should have 12.5 to 13.5 with engine off. Fire up engine and your voltage should jump to 15.5 or so volts. As the engine runs the voltage should drop to 12.5 to 13.5 volts. If your voltage does not drop after engine is running for a bit your voltage regulator is not working.

Coyote machine · Mar 10, 2012

17.xx is way too much output- enough to cause the battery to explode and throw acid all over you and everything else around it. While wearing safety glasses, long sleeved shirt and gloves, CAREFULLY remove the negative battery terminal and then the positive and place the battery in something safe, (HD plastic or wood crate or something similar, with a blanket or some such thing to cover it during transport). Have it load tested at a local facility after explaining what its been reading at 17.xx volts. Evidently the alternator is not your issue. By load testing the battery and checking the specific gravity of each cell you will be able to rule out the battery or find that it is indeed the problem. Report back results, and be careful; no one wants to experience a battery explosion under any circumstances.