Cmm1200 New Batteries only partially charged

JEC

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I installed new batteries (previous batteries 6 years old) in my CMM1200 Type 2 mower and it worked fine for 1 mowing but it did not recharge the batteries fully. When I put the charger on it only has the green light. The red light does not light at all. After a couple days the batteries are back to 12 volts even up from 11.6 volts. Do I have a charge problem? Maybe my old batteries were ok and the charger was bad.
 

motoman

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Those sound like the Nickel batteries in my BD chain saw. The owners manual spells out the charging procedure and it is different. Overcharging is not good and (memory) those batteries like to be stored in a slightly discharged condition (?memory?). After 2 years of neglect I was surprised that the batteries still worked without being charged. Suggest get a manual and read if you can.
 

Luana

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Sorry to be so late to the party. I have read of others having charger problems with the CMM1200. I have/had a CMM1000 that I recently junked and the battery for that machine lasted for some 16 years. In fact, I bought a used CMM1200 off of Craig's List that had a bad battery and swapped the battery from my original mower so it is still going strong.

Here's what I think: The CMM1200 mower uses a different circuit board and a different charger than the CMM1000. I think the newer model has a design defect, actually I KNOW it has a design defect because it eliminated the "state of charge" meter of the CMM1000. I think the newer board or charger did not fully charge the battery and the result was the battery was discharged to too low a capacity and THAT lead to the short life of the battery. This may have come about from the original instructions to always keep the battery charger connected when not using the mower.

Whenever I used my CMM1000 I would always stop whenever the state of charge meter dropped into the yellow band on an easy cut and I would then recharge the battery overnight. I did NOT as a rule charge the battery if the meter was not in the yellow range and I never ran the mower with the gauge in the red area. I never left the charger connected beyond maybe 48 hours at the most.

If you are handy with electronics I could make some suggestions for a new charging system. It would be somewhat involved but it would work better than the original system.
 
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