BMS Battery cell replacement

[Mattjenkins1990]

Hi All,

I have a 48V11.6Ah Bottle-09 Panasonic Battery Pack from BMS Battery

Like this: https://bmsbattery.com/ebike-battery/701-48v116ah-bottle-09-panasonic-battery-torque-sensor-battery.html

I have been running this for around a year and a half and all is still well with one exception. When checking the battery status by pushing the display i notice that even straight off the charge the top bar remains red and the second is amber.

The display shows the same almost immediately starting riding the battery status drops off to 3/4 bars.

I am wondering what i can do to sort this out without buying a whole new battery.

Should i try and find the Cells which are not charging and charge them individually for a few power cycles.
Is it possible to purchase and replace cells for this battery ?
Is there someone out there that could do this for a relatively small expense or will the cost be comparable to a new bottle ?

Any advice would be warmly received.

Many Thanks,

Matt.

 

[anotherkiwi]

Bars are great but what does a Voltmeter say? If you have LCD-3 or 5 on the third screen you have a voltage readout which in my case is quite accurate.

How many times has it been charged?

Do you leave it on the charger long enough for it to balance?

Do you ride a lot on steep hills in max assistance level?

Maybe you have a bad cell or two, maybe the battery is tired after 18 months like mine is...

 

[Mattjenkins1990]

Hi,

Thanks for the reply.

I do indeed have an LCD-3 display. I will check the third screen out tonight.

How many times has it been charged?
Probably around 500 times (estimate)

Do you leave it on the charger long enough for it to balance?
I usually charge it overnight so i would assume this is long enough.

Do you ride a lot on steep hills in max assistance level?
Not especially, one or two steep hills on a 10 mile round trip commute which i do almost daily.

I think this is probably the case, maybe a couple of tired or worn out cells. There are a couple of places in London that look like they may be able to test and repair the battery but i figured some advice before going down the shop would be smart.

How are you going about your's, are you getting it repaired or purchasing a whole new battery ?

Many Thanks,

Matt.

 

[Deleted member 4366]

The cell-packs are not easy to repair unless you have the right equipment. You might be able to claim a bit of capacity back by rebalancing.

You have to open up the case to get at the multi-pin connector. There, you can measure the individual cell voltages. Charge up the battery before measuring. Report the results here, then we can decide what to do. Put one probe on the cell-pack negative and the other one on each of the pins, so you get 13 results from 4v to 52v.

 

[fos'l]

Also, be glad that you didn't purchase a Dillenger battery. My two 36V, 10 a/h units both failed in about one year and 50 or so charging cycles. Took apart the first one and the batteries were no-name (didn't even have the courtesy to use knock-offs). Will dissemble the second one soon.

 

[anotherkiwi]

How are you going about your's, are you getting it repaired or purchasing a whole new battery ?

I have been lost to the Dark Side of the Force - LiPo...

I use the knackered one on the flat around town and a 20 Ah LiPo battery that cost a little less than that 10.4 Ah Li-ion for further afield.