5

I have a John Deere D110 that last ran around two weeks ago. I went to start it last night and nothing; it wouldn't even crank and the starter wasn't even clicking. I thought it might be a completely dead battery, so I left it plugged in to a charger overnight and went back out this morning. The charger said the battery was charged.

I tried starting it again and same thing; nothing. The headlights turn on, as does the little hour display so I figured the battery has power. The fuse isn't blown, as if it was the little display wouldn't turn on. The brake is properly engaged, blades are off and the seat is properly down.

I grabbed a multimeter and tried to test the battery; its supposed to be a 12 volt battery but I am only getting a reading of 6.88 volts. Would this voltage be low enough to cause the mower to not even try to crank?

Would this indicate that my battery is dead?

6
  • do the lights dim when you try to start
    – Traveler
    Sep 27, 2022 at 18:51
  • How old is the battery? Sep 27, 2022 at 19:01
  • Battery is original, a few years old. Mower itself has 127 hours on it, if that matters. Sep 27, 2022 at 19:05
  • 6.88 volts is strange. Even if a cell is bad that should only knock the voltage down by about 2 volts.
    – Hot Licks
    Sep 27, 2022 at 19:26
  • ...becasue 3 cells are bad - i.e. half of them. Replacement time indeed - perhaps also check the charging system on the tractor, and/or the maintenance routine for the battery in the off-season.
    – Ecnerwal
    Sep 27, 2022 at 22:01

2 Answers 2

5

Your 12v battery should be above 12v when fully charged. Sounds like you battery is dead. As for the cause, that may require additional diagnosis. Maybe the battery is bad, maybe there is some parasitic drain (some electronics running when mower is off), maybe there is a charger issue.

Maybe try disconnecting the battery from the mower. Charge it and see if it retains 12v immediately after the charge as well as over the span of a day without being connected.

You could also try jumpstarting it with a car. That way you know its not a starter issue. (but it doesn't sound like thats the issue)

3
  • 1
    I like the idea of using a car to jump start it. It would provide useful information. If it cranks over and / or starts, you know it the battery. Frankly at 6.8v that's not even close and the battery probably developed an open circuit internally. Sep 27, 2022 at 18:42
  • I did try using a jump pack to try jumping it and still got nothing. I found this video on YT with the same issue on the same mower and when he tried jumping he also got nothing: youtube.com/watch?v=aw6asCbI6Qc I am taking the battery to autozone to get checked in a moment. Sep 27, 2022 at 19:03
  • 1
    It could be several things: Those mowers have interlocks to protect us against ourselves (trying to make them idiot proof), such as a seat switch that turns off the engine if the person steps off, that may have gone bad, the control board may have gone bad, the starter switch (key) maybe failed. The started solenoid may have crapped out. Do the lights work? If so, the battery is probably OK, maybe. I've also seen ppl use cheap $ss jumpers or other kits to no avail. Start with ENSURING YOU HAVE at least 12V on the battery with or w/o jumpers and you have your fat $ss on the seat! LOL Sep 27, 2022 at 21:43
3

Yes, a reading of 6.88 volts after charging the battery is too low to start the mower and generally means the battery is toast.

If you want to be sure the battery is toast before buying a new one, disconnect the battery before re-charging/re-testing in case something on the mower is draining it. If the battery is 5+ years old, it's likely time for a new one either way.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.