My Lawnmower Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
88 Posts
Discussion Starter · #1 · (Edited)
My Craftsman lawn tractor seems to not be able to hold a charge on the battery. I charge the battery and overnight it drains and won't even turn the motor over. I assume there is a short somewhere that keeps draining the battery, where do I start looking?!?

Edit - It is a brand new battery as of last fall.
 

·
Senior Member
Joined
·
1,329 Posts
Steve, befor I would go to searching for a short in the wiring, I would take the Batt. to a parts store and have them do a pull on it. Then you will know for sure if the batt. is good or not. The batt. might have the short in it. Good luck , Doc
 

·
Registered
Joined
·
88 Posts
Discussion Starter · #3 ·
I'd think that could be a problem if I hadn't had a problem with the last battery too. It wouldn't hurt to have it checked though.
 

·
Senior Member
Joined
·
1,329 Posts
If your not in a hurry, disconnect the batt. charge it then connect it back up tommorow and see if it lost its charge over night.
 

·
Premium Member
Joined
·
601 Posts
If you are getting "never start" batterys, that's why every one has a problem :bag:
 

·
Ret. Moderator
Joined
·
498 Posts
Change your battery terminal ends ... I just went through the same thing with my Scag .
 

·
Registered
Joined
·
59 Posts
Two batteries in a row?

Something isn't shutting off. I would test the diode on the engine stator output line (or lines). From your description, it's not an issue with the battery failing to charge, but instead is getting run down overnight. If the diode on the stator / alternator feed wire is blown, there will be nothing to keep juice from running back from the battery to the stator (and thence to ground) when the engine is off. It forms a circuit just as if you had left the lights on all night.

With heavier amperage alternators, you may find two wires coming from the stator, not one. Either way, the diode in the line serves as a rectifier and will change the AC to DC current by preventing the current from moving in both directions. It might be part of the voltage regulator, depending on the design.
 

·
Registered
Joined
·
88 Posts
Discussion Starter · #9 ·
Two batteries in a row?

Something isn't shutting off. I would test the diode on the engine stator output line (or lines). From your description, it's not an issue with the battery failing to charge, but instead is getting run down overnight. If the diode on the stator / alternator feed wire is blown, there will be nothing to keep juice from running back from the battery to the stator (and thence to ground) when the engine is off. It forms a circuit just as if you had left the lights on all night.

With heavier amperage alternators, you may find two wires coming from the stator, not one. Either way, the diode in the line serves as a rectifier and will change the AC to DC current by preventing the current from moving in both directions. It might be part of the voltage regulator, depending on the design.
^^^ This...

I'd bet money this is the problem. When I shut the mower off I look at the needle and it looks like it takes a small dip BACKWARDS when I turn off the key so it makes sense. I'll have a look at it in the near future, hopefully it's an easy fix.
I have read all the responses and there are a couple other things I'll check too but I bet this is the culprit. Thanks for the help all - I'll report back my findings.
 
1 - 9 of 9 Posts
Top