li-on battery charging question/problem

[sal_park]

Hi guys,

I'm seeing some odd/different behavior when my battery charges (36v Li-on). The charger has always got hot (the case temperature is hot enough so you don't want to pick it up) and I've drilled some holes in the case to try and aid air flow. The only feedback on the charger is a red (charging) / green (ready) LED and where as this used to be red for say 2 hours and then go green it now flicks between the two colours seemly at random, although it will settle down in the end to red and then go green when charged.

Any ideas ? Perhaps I've got some dying caps ? (charger has been used 10 time a week for the last 2-3 years)

I've not had any issue with the battery running out of charge btw.


sal

 

[dnmun]

how long does the battery charge in the red led mode now? is it equivalent to the amount of charge you remove?

do you have a voltmeter? can you post up a picture of your battery and charger so we know what you have?

 

[sal_park]

how long does the battery charge in the red led mode now?

About 2-3 hours which has been consistant over the life time of the battery.

is it equivalent to the amount of charge you remove?

Yes

do you have a voltmeter?

yes, last time I check it was around 40 volts.

can you post up a picture of your battery and charger so we know what you have?

Will do in a sec

 

[wesnewell]

Cells out of balance will cause the bms to shut off at HVC when one cell reaches it. It then bleeds that cell down and once it goes below HVC, the charger starts again to bring the lower cells up to voltage. The cycles can be fast and many. I suspect that's what you are seeing. Just a wag since I don't use bms's.