Strange Battery Issue

[Hoefler]

Batteries seemed to work fine (Interstates). The other day, I jump in to start it and nothing-not even clicking sounds. I hook up a 24 volt charger and set it on low for a few hours. Still nothing.
I check voltage-over 24 in sees and over 12 individually.
The strange thing-when I hit the starter, I can hear a "stirring" sound from one of the batteries. I also noticed a sulpher-battery smell in the cab after trying to start.
I replaced the stirring smelling battery and now all is fine.
Question-what happened to the battery? Plate fell off? Curious at this point.
M715 is now cruising the farm again.
Pete

 

[tennmogger]

That cell went 'high resistance', meaning it no longer can provide higher current and will not take a charge. The sound you hear is the electrolyte cooking. The voltage across the bad cell will be very high compared to the other cells (in both charge and discharge cycles). A voltmeter draws very little current so the voltage looked ok. Put a load on the battery and check voltage and it won't be 12v.

When you replace a seriesed or paralleled battery, you should replace both (or all four). The replacement betteries should be near same production time if possible. With a new battery connected with an old battery there is a cell mismatch and problems will follow. If the old batteries are the same age, the others are probably near end of life too.

 

[Hoefler]

Tennmogger,
Thanks for the explanation. I didnt know any of this stuff.
I will replace the batteries.
Pete

 

[dmetalmiki]

Before you change one or all, did you check the acid levels? worth a try, that would make a smell if empty

 

[Hoefler]

I will look at that.
Pete

 

[dmetalmiki]

P.S. And a LOUD bang! if anything like a spark occurs. (get checking).