4440 dead batteries

isuvinny72 · Oct 13, 2015

A battery update. I charged them overnight, then let them sit a day (not connected) and checked with a load tester. One was dead, the other not much better - so I put 2 new ones in. The tractor fired right up and seems fine. The only possible issue now is the gage in the cab reads that they are over charging. Could there be an issue with the alternator? I have a meter, If I put it on one battery when its running what should I be getting for a reading? or how do I test for this? Thanks for all the ideas!!

Bob · Oct 13, 2015

Check the 3-termianl connector at the alternator for rust and corrosion, and clean as needed.

Lee B · Oct 13, 2015

Yes there could still be issues with the alternator. It's working, but it could also be draining the batteries overnight and/or charging full blast always.

Put your voltmeter set for 20 DC volts on the batteries while running, you should see 13.5 to 14 when alternator is warm and even higher when cold. But higher than 14.5 when warm to the touch means that the voltage regulator is shot and overcharging the batteries. Concurrent with this failure is often the draining of the batteries overnight problem, but not always.

Charge all new batteries first before starting and especially before taking voltage readings as above. Only then can an overcharge at the ammeter be taken seriously to show something wrong with either the ammeter or the charging system and the higher than 14.5 volt test above might actually work since healthy batteries won't go much above 14 until they are very fully charged while still being fed 15 or more amps of charging current each.

4440 dead batteries

isuvinny72

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Bob

Well-known Member

Lee B

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