Mini atv batteries

[Conservation]

Well, this may very well be a battery quandery for me. My son has a mini atv, gas powered. I replaced the original battery in the fall. It was probably only 8 months old. I went to NAPA and got the sealed equivilant, and it looked just like it with a similar number on the side. Works great. Until the last time we went to start it. Nothing. We keep the maintainer that came with the machine plugged in all the time. The voltage after putting it on a grown up charger is 13.5V, but as soon as you hit the starter, down to 5V or less. Won't turn it over at all.
What am I doing wrong?

 

[J_J]

Well, this may very well be a battery quandary for me. My son has a mini ATV, gas powered. I replaced the original battery in the fall. It was probably only 8 months old. I went to NAP and got the sealed equivalent, and it looked just like it with a similar number on the side. Works great. Until the last time we went to start it. Nothing. We keep the maintainer that came with the machine plugged in all the time. The voltage after putting it on a grown up charger is 13.V, but as soon as you hit the starter, down to V or less. Won't turn it over at all.
What am I doing wrong?

Check the voltage on the maintainer charger . Maybe the battery has a bad cell or two. Try and start it with a regular battery. Just don't hold the starter very long. Also take out the small battery when you do this.

 

[Conservation]

I started it the other day with the charge on it. Not drawing hardly anything. The battery would keep the ignition running with the alternator. I think you are right about dead cells. I need to check voltage with the maintainer. Maybe it is cooking the cells in the little batteries.
Thanks for the input!