Battery Drain

[lefty]

John Deere
SCOTTS 1642H
GX1642S155388
Date Code: 052301

I'm told by the owner that the battery will drain if the key is in the ignition in the off position. I can't think of any other reason for that, if it is true, then a bad ignition switch. Is there a scenario where this happens for another reason?

Thanks.

[RoyM]

If the charging circuit is not wired through the switch it can do that if the diode fails. What are the make and model numbers off the engine?

[lefty]

It's a Kohler

Model: CV16S
Spec: 43526
Serial: 3112806273

[SUKI]

Lefty, What you got is actually a Scotts S1642 mower. It the Sarbe 1642H that has the model quoted. But I did lookup the Scotts S1642 and it does have the Kohler CV16-43526 engine.

According to the wiring schematic the stator is setup just like the Briggs dual circuit stator. It is directly connected to the battery at the starter relay [solenoid] via the 15 amp fuse. As Roy suggests it can be a bad diode.

But to be sure where the drain is coming from do an amp draw test at the battery with the stator disconnected. This verify if it is the stator the causing the drain or that you indeed have another problem. Also note used batteries can develop internal and external problem that will self drain them. Things like the plastic battery casing becoming conductive. A lot times I can find voltage present on the case when this happens.

[lefty]

I got my hands on it and I don't find a draw at all. Key in, key out, nothing.

Would a failing diode cause an intermittent drain on the battery or does it just go?

I would think that whether the key is in the ignition or not would be simply coincidental?

[Arkie]

If you cannot verify any leakage by using a milliamp meter with the key switch off, key inserted or removed try this:
Take a battery cable off, Pos or neg and leave it off for few days and then re-connect and do a crank test. (or test the battery with a 100 amp battery load tester)
Most likely a bad battery.

It would be very uncommon for a slicone diode to have reverse leakage unless shorted.
(tehy jus tdo not become erratic in reverse leakage)

Have you noticed the price of auto bat's lately???

[SUKI]

Same price percentage wise is going on with lawn mower batteries too.

[Arkie]

I've got a lawn tractor battery that will do very similar Lefty describes.
235 CCA

On the work bench It will charge up using a auto charge charger and test A-ok on a 100 amp load tester, let it rest for 24 hours connect a load tester and volts check ok with no load, apply load and voltage goes to ZERO, remove load and voltage returns to 12v immediately. Unusual for volts to show 12v immediately after removing the load. Usually will indicate low volts after showing zero volts shows under load.

Will operate ok on a lawn tractor, as long as the engine is being used and charges and starts the engine ok but will die within 24 hours when not being used. Batteries can do some strange things sometimes.

[KE4AVB]

Just wondering Arkie have you have one to flip charge? IF you haven't it will throw you for a loop when it happens.

[Arkie]

Just wondering Arkie have you have one to flip charge? IF you haven't it will throw you for a loop when it happens.

What is flip charge?