Is it Possible.....#2

[stemil]

For lead acid batteries to fail suddenly? By that I mean that they have good charge and range one minute then all of a sudden nothing.
The batteries are about 2 years old and have given very good service up to now, I'm still getting 38v, but the moment any load is put on them the voltage drops down to under 4 volts.
My experience in the past has been that they just get weaker and weaker then peter out.

 

[Scottyf]

Does sound like a fault with the battery. Usually getting a battery of any kind to read a voltage is simple. But usually when you apply load is the give away.

 

[flecc]

I've already replied to your fuller question in the other section stemil, but here's that answer:

It is possible yes, the lead plates as they thin with age can buckle and short. With a weak and buckled plate almost touching an adjacent one, applying a load results in a further small movement and resulting shorting of the voltage.

Two years is quite a good life in e-bike usage.

 

[Deleted member 4366]

One thing you could try is to short them out completely for a short time. ideally, you want to put a bit of metal in the connectors or hold each with a pair of pliers, because the connectors might get damaged. At the full 36v rather than individual batteries, Touch the two connectors together for about 1/4 of a second. you'll get sparks and they may get hot so be careful. What this does is to burn off any whiskers between the plates, which can form with age. It's worth a try because they're not working at the moment.

 

[stemil]

Thanks for your replies, I shall give that a try d8veh.

 

[banbury frank]

Hi

Be very careful A fully charge battery can vaporize anything you short the battery with giving you serious BURNS use heavy gloves our pliers



Frank