battery done ?

[topper]

hi all, i bought an unbranded juicy sport type 36v bike. if i open the thottle, wide and fast. the battery cuts power, i attached a volt meter, this shows a voltage drop to 31v witch explains power cut.battery fully charged is allmost 42v is it normal for such a large drop in voltage under load.i was told the bike is 18 months old and ridden only once
so i don't think the battery has been cared for. battery has bms and 10 square cells.
which type of battery could this be? is it possible to make some kind of repair . any comments/ input will be much appreciated
cheers alan

 

[Synthman]

Yeah it's normal on an old/failing battery. My previous battery (which is 5 years old) would do that if I gave it continuous full throttle for more than a few minutes.

You could open the battery up and measure the cells individually and see if there is a large difference in voltage on any of the cells, if one is significantly lower than the others then you might be able to replace it if you can source a replacement. The battery probably wasn't stored well and not charged enough, and it is likely to be older than the bike itself.

It is probably a lithium battery! More specifically NiCoMn or LiMn2O4 chemistry. It does not sound like a LiFePO4 though.

 

[JuicyBike]

Hi Alan
If you can give me the frame number, battery number or a photo I can let you know if this is a genuine Juicy and see if we can help. We keep stocks of all parts for all our bikes and should get you back on the road quickly. My only concern is that you say this is an "unbranded" bike.

 

[topper]

hi again and thanks for the quick response.. i say it's "unbranded" because
there are no frame numbers or distinquishing marks on this gloss black bike, apart from zoom forks shimano gears, apse brake levers and 26" kenda tyres, nothing on the black battery pack, but i noticed
on the controller there is a date of 2009 i'll post some pic,s if i can work out how to do it.
i did run the battery down last night so i could recharge fully today in the hope of rejuvination ( the battery not me lol) and the charger light shows red for a second then green for a second like it's pulsing.
is this good ? or very very bad
thanks again for any input alan

 

[JuicyBike]

Hi Alan
OK, so not one of our bikes. It does sound like the battery has a defective cell within, though this could have been caused by a defective charger (showing the battery as charged when it actually wasn't).

I suggest that tampering with the battery yourself is dangerous and I would not encourage that.
We offer a test service if you send us that battery and charger: £12 for the test plus the cost of re-delivery (if the battery is OK.)

Hope this helps.