RZT50 battery drain

[ckoral]

couple weeks ago I had a dead battery. Charged it up and mowed about 1/4 acre. Right in the middle of mowing it killed. I jumped it this time with the car. The battery was still dead and it only made it another 40 feet. I replaced the battery and have mowed an acre 2 separate times. Fine, batter was bad, problem fixed RIGHT?

I just went out to mow again and it would not start. I jumped it and mowed the entire lawn just fine. Pulled it back in the garage and turned it off. Then restarted it and it started right up.

What is going on and how do I go about troubleshooting?

Thanks

 

[KennyV]

WELCOME to LMF...

Check the battery cables (both ends) they have ti be clean & tight...
With the engine running above idle you should measure around 14 volts across the battery... and just a bit above 12 volts with engine off... If you are less than 14 volts running your voltage regulator or rectifier is bad and that is most likely where the first battery was discharging to... and after enough times running down toward zero volts, along with age .. that battery failed...

Check te voltages and post back... :smile:KennyV

 

[ckoral]

I checked voltage via the built in voltage meter. It was 12 off and 14 running. I have not checked this with the new battery but I suspect it would be the same.

 

[ckoral]

so 12 volts off, 14 volts running

If I disconnect the + battery it runs for about 8 seconds then kills.

 

[KennyV]

If you have around 14 volts DC & no AC along with it your charging system would seem to be okay...
You should not run it without the battery connected, I don't think the regulator can adjust for that type condition..

If Your battery dies again during operation... I would look for a bad connection at either end of the battery cables... both positive and negative cables...
Check for a fuse OR a fusible link on the electrical system... a bad connection is especially frustrating to locate ... because it is going to be 'kinda' working 'sometimes'... But keep after it you will eventually check the problem connection and when putting it back together your problem will just never reoccur... :smile:KennyV

 

[ckoral]

I move the wires around while it is running and cannot make it kill. I called my local cub cadet dealer and he hinted that it might be a voltage regulator. I'm guessing it is that black thing with two white wires and a red wire running into it. It has heat sync attached to it. This is a Kawasaki fh661 engine. Wish I knew more about this stuff.

Thanks for the help.

 

[thegman]

It could be the voltage regulator going bad. Here is a debug technique I found.

RTZ 50 voltage regulator debug


Locate the three wire regulator, and unplug the harness, And with the voltmeter set on AC volts, probe the two end wires with the engine running at least 1/2 throttle, reading from stator should be at least 28 volts AC. If it is, it is ok, The set meter on DC. plug the regulator back in and probe the center terminal with red lead and black to ground and read the meter again with the engine running at least 1/2 throttle, reading needs to be at least 14 volts DC, if not, the regulator is bad.