Broken BMS Phylion Battery JCEB360-8.8 - Help

constantin_d

Finding my (electric) wheels
Apr 8, 2019
6
0
Romania, Bucuresti
Good day,

My name is Constantin Drosu.
I have purchased a used Maino Elettra electric bike with Suzhou Phylion Battery JCEB360-8.8.
It seems that the BMS board from inside the battery is broken. After some discution with the owner I found that he opened the battery for some checks and plugged by mistake the charger handshake connector into the BMS configuration socket (SDA SCL one) instead of the correct handshake socket. Now when I connect the cells connector to the BMS board, the management integrated circuit gets very hot. I imagine that SDA SCL Clock Gate is shorted somehow and the IC gets hot because the processor is trying to start the serial comunication port.
The integrated circuit of BMS is OZ8940ATN produced by O2Micro and the battery has 36V 8.8 Ah with 10 cells Li-ion.
I have the expertise to understand and repair a BMS circuit, but the only solution I can see in this situation is to replace the entire board or the integrated circuit.
Unfortunately I can't find any documentation or datasheet of this integrated circuit and I don't know if before to put in service the new part needs some configuration regarding number of cells, current draw, cells capacity etc.
Also I can't find this IC anywhere in Europe, just one website in China.
Can anyone of you help me with some advices? Maybe where I can find an replacement board or an equivalent BMS board or IC that can work with the Phylion Charger with handshake system?
Or any other solution..? I am all ears :).
Cells are in good condition so I don't want to change them.
Please see photos for see the battery and circuit board.
Thank you very much.

Best regards,
Drosu Constantin
 

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vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
As far as I can see, there is no handshaking with that PCB. The connectors are not clear in your photo, but it looks like the two with double black wires are both sensors and the one with the green connector is for the battery charge level indicators.

Are there any other connectors that are not shown in the photo? Maybe you could provide photos that show everything.

There's a socket for wires that send a temperature signal to the charger to allow charging. Are there wires that go from there to the charge socket in addition to the black and red wires on the larger white connector? If there are, you could probably put a resistor across them to give the right signal, then use a standard Chinese 10S BMS for everything else.
 

constantin_d

Finding my (electric) wheels
Apr 8, 2019
6
0
Romania, Bucuresti
Yes, in adition to the red and black wires there are another three wires. So the charging port has in total 5 wires. I attached a picture with the wires explanation. The Phylion Battery > Charger has a comunication protocol for identifying that the right charger is used.
That part I presume that works.
My problem is that some one mixed the connectors on the BMS board and burned something in the integrated circuit and now it gets very hot immediately after Power ON.
Thank you.

1554733961304.png
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
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Basildon
You can buy a standard 2-wire charger for £18. The BMS will cost about the same. Cut the connector off your charger and wire just the + and - to the new one, or change the connector in the battery to match the new charger.

Your only hope of getting one of those OEM PCBs is to take one from an old worn out battery if you can find one. here in the UK, we can be pretty sure that Halfords have warehouses full of batteries that they've taken out of their bikes.
 

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
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OK, I will try to reach Halfords for now. After this I will try to replace the BMS entirely.
Thank you!
They are available very cheaply on ebay for example:-

https://www.ebay.de/itm/36V-37V-16A-10S-BMS-PCB-PCM-Li-ion-LIPO-Lithium-Battery-Power-Protection-Board/173526520924?hash=item2866fc945c:g:X5cAAOSwSflbllJ1

https://www.ebay.de/itm/10S-36V-Li-ion-Lithium-Cell-40A-18650-Battery-Protection-BMS-PCB-Board/183478560925?hash=item2ab82ca89d:g:H6EAAOSwHTlbvQop

Pick one that can handle a higher current than you need, and do follow some of the good battery builds on YouTube for example.

http://www.ebikeschool.com/how-to-build-a-diy-electric-bicycle-lithium-battery-from-18650-cells/

Remember, they can get dangerous if shorted, so be very careful.

Best wishes

Andy
 

constantin_d

Finding my (electric) wheels
Apr 8, 2019
6
0
Romania, Bucuresti
Thank you for the help.
If I choose to replace the BMS board, my problem is that the charger does not output voltage by itself. It needs some activation from the BMS board. The general BMS board from Ebay doesn't have this activation I presume.
Do you think that the activation is only from the NTC temperature sensor read?
Could I simulate a good signal with a resistor?
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,986
Basildon
It would only need one or two wires to read an NTC, so perhaps something else is going on.

As I said, you can buy a dumb charger for around £18 and convert your battery with a dumb BMS. You should get a BMS that can output at least 25 amps.