got a dead battery to work (at least nominally)

[wiscootsin]

I picked up a non-running scooter and quickly realized the battery was dead. When I tried to hook it to my trickle charger it wouldn't register. Hooked up my multimeter and no voltage across the leads. So it was totally dried out.

I found something online that mentioned cracking it open and putting water in it. I figured it was worth a try? (correct me if there are other better options out there.

Anyway, I figured I would show what I did to get it working.

Even after adding the water, the trickle charger wouldn't start it. So i connected the dead battery in parallel to a good working battery from my other moped, then I put the trickle charger on the leads of the good battery. It worked!  Here's a picture.




After a while water began to bubble out of the top. I took some of the excess fluid out and taped it shut. Multimeter read 12.75V.

So I put it in the moped, shot carb cleaner in with the airbox removed and it started up. Now that I know the moped is working fine (ish) I may actually buy a battery.  When I drove it out it stalled at a red light after idling for almost two minutes. 

[190mech]

"Smart chargers" wont charge a battery if its below a certain voltage..You just fooled it into charging!A low battery shouldnt cause stalling unless its a DC CDI iggy system..What kind of scoot?

[gsx600racer]

Jan 5, 2019 2:19:39 GMT -5 190mech said:

"Smart chargers" wont charge a battery if its below a certain voltage..You just fooled it into charging!A low battery shouldnt cause stalling unless its a DC CDI iggy system..What kind of scoot?

That's why Iv kept my "dumb charger". LOL

[wiscootsin]

Jan 5, 2019 2:19:39 GMT -5 190mech said:

"Smart chargers" wont charge a battery if its below a certain voltage..You just fooled it into charging!A low battery shouldnt cause stalling unless its a DC CDI iggy system..What kind of scoot?

Yeah after thinking about it may just need a way better carb clean, new fuel, and maybe some tuning. I just really wanted to get it out and test it!

03 Kymco zx 50 super fever

[ThaiGyro]

Some batteries have excess corrosion on the internal positive and negative poles. Though a dumb charger or series charge, like you showed can help, My belief is that is is temporary. Bad batteries may waste your time or strand you. I have compromised with AGM, or gone with NiCad. My TRX850 has an AGM that is now 5 years old...rarely run it, but it never fails to charge!

[ThomasTPFL]

We used to hook old batteries up with a headlight in parallel to get them to charge. Sometimes they neeed to be charged r e a l l y s l o w to work. On my scooter I’ll turn the ignition on and tie the brake lever down to achieve that.