Dead cell in GM LiFePO4 Pack

[scottysoftness]

I got my pack from GM and it seemed to work OK.  I was a bit disappointed in its performance, as I expected to get more distance before it started cutting out, but knowing nothing about these bikes I figured that was normal.  Then I had my more technically inclined friend look at the battery, and he quickly told me that one of the cells is dead (it only charges to about 0.9v, and loses that within seconds of disconnecting the charger).

I have emailed GM about this, but I have not received any reply so far.  Has anyone else had any luck in this regard?  If not, is there someone else I could buy a single LiFePO4 cell from?

[sigpaw]

I have TWO of their 36v packs. BOTH of them have had a cell die. Then each pack opened up respectively. It's been weeks and NO replacement. At least three other folks (not counting you and I) have had the same problems.

We need to start a "Buyer Beware" thread and keep it at the top of the list by constantly replying to it. Until they address our problems!!!!

What does everyone else think?


These packs are REAL TRASH! BUYER BEWARE!!!!

[redbike]

Yep - I concur with that. I would not recommend them to anyone. Also I think the controllers are a bit dodgy as well. I really hope the motors are OK!

[biohazardman]

Phllip is often a bit slow on the e-mail so be patient.  Many problems with the new batteries also may slow things down a  bit more.  Good luck and keep after him.

[scottysoftness]

They claim they just got them in (I've heard that before...) and I should get it next week. We'll see.

[sigpaw]

Yup, they told me they had finally received some replacement cells. But that was a week ago, and still nothing...

[algub]

hi friends,
I have the same problem with my akku from GM golden motor
36 V 16Ah: I loose approx 30 percent capacity after 15 partial loads.

I think there are dead cells. I opened the akku (it is not a problem) but
the cells are connected in blocks and spot-welded and assembled in plastic frames.
I do not know how I can separate it to check the single cell.

Is there somebody who can help me??

Many thanks in advance

algub Germany



 
 

[algub]

hi friends,
I have the same problem with my akku from GM golden motor
36 V 16Ah: I lost approx 30 percent capacity after 15 partial loads.

I think there are dead cells. I opened the akku (it is not a problem) but
the cells are connected in blocks and spot-welded and assembled in plastic frames.
I do not know how I can separate it to check the single cell.

Is there somebody who can help??

Many thanks in advance

algub Germany



 
 

[Gregte]

hi friends,
I have the same problem with my akku from GM golden motor
36 V 16Ah: I loose approx 30 percent capacity after 15 partial loads.

I think there are dead cells. I opened the akku (it is not a problem) but
the cells are connected in blocks and spot-welded and assembled in plastic frames.
I do not know how I can separate it to check the single cell.

Is there somebody who can help me??

Many thanks in advance

algub Germany



 
 

The best you can do if you do not want to cut the welded tabs is to put a load on the battery and measure the individual paralleled cell blocks. These blocks are of course all wired in series.

For a load you can use regular incandescent light bulbs. If you use a 200 watt light bulb it will draw much more than 200 watts because it will not reach its full brightness and heat because the battery voltage is much lower than the 230 volt house voltage the light bulbs were made for. Whenever a resistance such as a light bulb is cooler than its normal operating temperature it will have much less resistance and provide a much higher load.

[bopa]

I got my pack from GM and it seemed to work OK.  I was a bit disappointed in its performance, as I expected to get more distance before it started cutting out, but knowing nothing about these bikes I figured that was normal.  Then I had my more technically inclined friend look at the battery, and he quickly told me that one of the cells is dead (it only charges to about 0.9v, and loses that within seconds of disconnecting the charger).

I have emailed GM about this, but I have not received any reply so far.  Has anyone else had any luck in this regard?  If not, is there someone else I could buy a single LiFePO4 cell from?

Looks like these problems are persistent - both the dead cells and the slow reply. I emailed twice in the last two weeks about a bad key switch on the 12ah Li batt and have so far heard nothing. Now one or more cells seems to have failed. I emailed about that today and will post an update in a week about the reply. Who else has recently had dead cells in a new (six-week-old) pack?

Bopa

[zpeter]

Hi,

I have the same problem, two cells dead in my lifepo4 36V/10Ah. No response for two weeks now. Anyone knows some other supplier of batteries?
/Peter