EM 5.7 replacement battery

[JIMMY_J]

EM5.7 is an Electric Motion Trials Motorbike.
My battery has been over discharged (1-2V per cell) and the BMS will no longer allow it to charge for safety reasons.
I was happy with the range and performance of the motorbikebike and would like to keep this economical and simple to get the bike back running. I can re use the charger and maybe even the BMS if its decent. Here are the specs:

Charger: ROHS LiPol 54.6V 15A

Battery: 25Ah and is a 13s
pouch type cells and there are 13 in series no parallel runs. Non of them are swollen or puffed




Motor: 5KW Golden motor

Controller: Kelly controller KEB 48601 (nominal voltage of 48v)

BMS: BNT-MP-M1005-001


All cells together are:
Width 10 1/4”
Height 7”
Depth 4 1/8”

The whole Pack was labeled: 82255140H[1178.45Wh] KHL13S1PXG6A013
Each individual pouch cell was labeled: KOKAM CO.,LTD SLPB82255140H, 90.65Wh KHL11XDRY0007 A7

I searched all these numbers but found nothing other then KOKAM makes batteries for a large variety of things

Looks like these pouches are li po and are supposed to be 3.7v each totalling 48.1v total with 13 in series
No parallel batteries so the 90.65Wh / 3.7v = 24.5 Ah per cell and for the whole pack

How do I determine the C rating of these batteries ?
Where do I find pouch batteries of the same size and Ah rating ? Most of the ones I can find are smaller
Should I get a new BMS like a speedict Neptune 15 or is the one i have decent?
Is it better to build a new pack out of a different type of cell ? What is popular now ?

I looked at the 21700 cells at 4000mAh , 13S 6P for 24Ah out of 78 cells but they are expensive!

 

[AngryBob]

That is a dangerously low voltage and I would strongly advise use of extreme care especially when charging due to high risk of explosive fire.

Unless they got that low due to sitting unattended for an extended period, several months, then the BMS would seem to be defective, and if they did sit, don't do that no more.

 

[AngryBob]

That is a dangerously low voltage and I would strongly advise use of extreme care especially when charging due to high risk of explosive fire.

Unless they got that low due to sitting unattended for an extended period, several months, then the BMS would seem to be defective, and if they did sit, don't do that no more.

 

[Kael]

Did you made any progress on this battery?
I had a identical battery to checkout after long stand still, 1 cell was only at 1V while others around 3.5-3.7V.
I managed to recalibrate the cells and now the battery is charging alright. After a first run it looks OK.

 

[JIMMY_J]

https://www.youtube.com/watch?v=97K7hRFDeYA

https://www.youtube.com/watch?v=YPN_6RA4pSg

Wont charge longer then a few minutes, The charger has been cutting out since i bought the bike. I suspect its the BMS. All cells are at 3.52v so why is the BMS stopping the charge and how do i bypass this to let it charge ?

Will the pack charge with the BMS disconnected?

 

[AngryBob]

I want to highlight something here.

"THE CHARGER HAS BEEN CUTTING OUT SINCE I BOUGHT THE BIKE".

You have a thread seeking an answer to a battery charger problem, and you did not think it was necessary to mention a problem with your charger which has been present since DAY FREAKIN ONE?

Describe the charger's behavior in as much detail as you can trouble yourself to achieve.

Metered voltage readings for charger, same for battery, any and all you have done or can do today.

3.7 in a nominal voltage for Lion, fully charged should be 4.2, 13 in series would be 54.6.

The charger may not have the output correctly set. The battery chemistry is unknown. Lifepo4 has significantly lower voltage ratings for individual cells. Roughly in the ballpark of what you are getting now.

The BMS can most definitely be defective, probability of this is greatly increased with the new and fascinating info that the charger has ALWAYS had a cutout problem.

Yes, you can charge without a BMS, even run without one, but it is not something I would consider for everyday use. Opinions vary on this one.

Since you have a standalone power supply, I would use that to attempt to fully charge individual cells, OUTSIDE IN A FIRE-SAFE AREA, then monitor those cells carefully for self-discharge and also temp during and after charge, then reassemble with BMS, discharge carefully while measuring usage, take readings with DVM throughout process, then attempt standard charger, after testing output voltage to verify correct settings.

 

[Austini]

Hi the previous owner of my EM5.7 put a speedict Neptune 15 BMS in the battery when the standard BMS died since then the battery keeps on tripping to the point where the bike is unusable, it can run for 10 mins to 10secs. The speedict Neptune 15 looks an awesome piece of kit that does everything but make the tea and any dealings with the supplier "Danny" has been prompt and informative but to no avail regardless of the amount of parameter changes inputted on the BMS the problem still exists. Does anyone else have a speedict Neptune 15 on their EM that works and what are your settings?
The battery will charge to 54V and all 13 cells sit around 4.1V but the charger won't work whilst the contactor (solenoid) keeps on tripping, so the thought process is the BMS is to sensitive and has too many variables for this battery or its wired up wrong.
I have a Ebike dealer looking at the battery now and we are looking at putting a more basic BMS into the battery as per the original. The dealer has concerns however over the design of the battery and would like a schematic of the battery before continuing, Em has, as yet not answered any queries.
The part that trips on the battery is the contactor (1 in the pic) and we can't work out what No2: in the pic is.
As all the cells seem ok I want to keep the original battery but if I can get one made up at the right price I would be happy to do that.
What are the exact specs for a replacement would I need? Voltage below 60 and between 48 to 54 is needed. its a 5KW motor. AH of 25AH plus I believe EMs new bikes are 40AH. What constant C? rating is needed and burst C? rating. As you can see batteries are not my realm, pistons and petrol are.

 

[JIMMY_J]

Thanks for your reply AngryBob

https://youtu.be/EwqiVhmYfuA

- the charger would rarely charge the battery fully without “tripping” I would have to unplug and plug back in to reset several times. Charge times would vary from 20min - 2 hours
- the charger says 54.6VDC @ 15A
- charger has a red and a green led and when its charging the green LED turns red

How do i trick the charger into turning on so i can check voltage ? It has a 3 pin cannon head 18mm connector

-as in the video all the cells have held for 6 months at their voltages of 3.49-3.53V pack voltage of 45.9VDC
- I figured these were Lithium polymer pouches 2.7 - 3.0v / cell fully discharged, 4.2v / cell fully charged

How do i test the BMS ?

-I was going to charge individual cells through the BMS leads outside tomorrow Then connect the charged pack to the bike and put load on it with the bike on a stand at the other end of some jumpers.

If I disassemble down to individual cells How should I Discharge The individual Cells once they reach full voltage of 4.2VDC ?

 

[bsutch]

I have a battery pack with one bad cell that I am selling individual cells from. $200 each plus shipping costs. email me at Brianpsutch@gmail.com if you are interested.