I have just disassembled a battery pack from a Lenovo laptop (Series: 45N1005 with six cells, Specs: 10.8V, 5.2Ah, 57Wh) and I would like to use the BMS for controlling a single 18650 cell (2.8Ah) which should power an Arduino board. I would like to have the overvoltage and undervoltage protection (see also my previous post).

I have tried to do some testing and see if I can read the voltage of a single battery through the BMS terminals, but the voltage is 0, so I'm wondering why.

Please see below how the board looks. Unfortunately, I couldn't find any information about its parameters or components and therefore I would like to ask if any of you can help me to figure out:

  1. If this BMS can be used to control the charging/discharging of a single cell instead of 6;
  2. How to test the BMS so that I can figure out the parameters. Which methods should I use?

Basically, I'm more interested in the overdischarge protection. That is, a cut-off voltage of 2.7 V.

Here is the unknown BMS with the sketched battery connection.

Top view: enter image description here

Top view close-up: enter image description here

Back view: enter image description here

The only searchable keyword that looked relevant was "94v-0", but the results were totally different than what I have.

  • \$\begingroup\$ Good luck. When you disconected power from the BMS you wiped out any data held in its SRAM. It'll probably refuse to ever work again. \$\endgroup\$ – Brian Drummond Sep 30 '17 at 11:49
  • \$\begingroup\$ It makes sense, but are you 100% sure of this? What does that mean? That if I want to have it working again I would need to have it powered and write the codes again (hypothetically)? Or? \$\endgroup\$ – Physther Sep 30 '17 at 12:08
  • \$\begingroup\$ Pretty much ... and you probably need a setup that only the battery mfgr has to write the codes again. \$\endgroup\$ – Brian Drummond Sep 30 '17 at 12:52
  • 1
    \$\begingroup\$ 94V-0 is a flammability rating for the PCB. A multi-cell BMS will probably not allow you to connect just one battery. To the BMS that would look like a multi-cell pack with failed batteries attached, and it would likely not operate as you want in that condition. Normally, when you only have one cell, you use a battery protection circuit rather than a BMS. The protection circuit guards against over-voltage charge, over-rate charge, under-voltage discharge, and over-rate discharge. You can buy cells with protection circuit built-in. That is what I recommend for future projects. \$\endgroup\$ – mkeith Sep 30 '17 at 15:44

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