OT - Lawn Mower electric PTO won't engage when battery is de

Pulled the mower (Cub Cadet 1525) out of the garage this weekend...

Two tires low and battery dead. Aired up tires, check oil, jumped to truck to get it started without any trouble.

Drove it a little and tried to engage the electric PTO clutch...Nothing.

Took it back to the driveway and cleaned up some of the connections. Jumped it to get it going again, pulled out meter to see if charging system is working and said 15.6V so tried to engage PTO and still nothing. Now thinking switch might be bad, grabbed the meter again and can verify that it is operating properly. Used tractor a while pulling a cart around the yard before parking back in the drive way for a few hours.

Still wanting to mow, jump tractor again and happen to engage PTO switch while still jumped to truck and it works. Went and bought a new battery and everything is good now. Question is why did it not work with a low battery. Seems to me if the charging system is good it should have had enough oomph to engage the clutch or am I missing something. Obviously needed a new battery anyway since it did not hold a charge after running an hour or so anyway so I am not really out anything other than time, just curious.

Kirk

lawn mower and motorcycles batterys just don't last because of size,, chances are the battery devoloped a cross short, causing the battery not to charge,, the motor was running off the genny to keep itself running, but not enough to charge dead battery.

I don't really question the dead battery, just why the gen/charging circuit would not engage the electric PTO clutch.

Mostly just trying to satisfy my curiousity,

Kirk

Your generator isn"t making enough juice to do both jobe. Try it with your cables connected to your pickup. bet it works.

I guess that is the obvious answer. It did work when jumped to the truck. That is what prompted me to just run out and get a new battery, expecially when the old one did not hold a charge after running an hour or so. Doesn't seem like it should take that much power to hold the clutch, but what do I know.

Thanks for looking,

Kirk

It's not voltage that's the problem it's the amperage. Those clutch's pull a good bit of amps to get going. With a dead short in batt it won't put out the amps it needs.

You need a battery maintainer, batteries cannot be allowed to go dead and then set for a month.

Kirk - Mine would pull the elec clutch in, but it couldn't keep up with the charging/running/clutch demand and would die from lack of ignition voltage at the most inopportune location. If I was on my toes, I could kill the clutch in time to keep it running. Usually it died in some forsaken place that only a tractor could get to. Time for a new batt.

It takes a fair amount of amperage to engage the clutch,but not alot to hold it in the engaged position. If you battery was shorted or bad,it would not have the reserve to engage the clutch. The alternators on a lawn mower are not high amperage, they usually only put out 10-15 amps,enough to keep the lights lit, the pto engaged, and a minimal amount returned to the battery to maintain charge if the battery is good.

or 6 months.