How long should voltage remain in battery?

[Barefoot_Wanderer]

HI Everyone,

I purchasded a Yasco 48V 15Ah Ebike Battery with 30A BMS off Amazon (I know, asking for trouble) and when I tested the battery in July this year, it had a reading of 53V and now I'm not getting a reading at all (see pic) - this is worrying because its been sat in my house doing nothing.

When I test a single cell which has been on the shelf for 6 months this still has a reading of 4v. Just a battery I had lying around, nothing to do with the battery being tested.

is this a sure sign the battery is made up of unbranded, cheap cells and poor quality? How do I find out??. Is it to be expected having no reading after 2 months of inactivity? It has a 1 year warranty so I'm not going to take it apart, obviously.

Thoughts/ advice would be appreciated

 

[AGS]

You have got your multimeter set to 20 volts full scale.

If you set it to 200 volts full scale you will get a voltage reading.

 

[Barefoot_Wanderer]

You have got your multimeter set to 20 volts full scale.

If you set it to 200 volts full scale you will get a voltage reading.

OK panic over, I did as you suggested (appreciate that, thank you!) and now get a reading of 53.8v (now Ive switched it on) 26v when off.

definitely looks like good quality battery. phew)

Thanks for help and lesson ;-)

 

[saneagle]

The 26v when switched off is not real voltage. It's actually 0v. You cannot draw any current with that 26v. It's just leakage charge through the MOSFETs.