Converting 5S 100 amp BMS to 4S and 3S BMS

[@markwilliams2830]

What a great explanation ! You have nerves made of Steel . I would be shaking like a Jelly Fish if I didn't own a microscope . A really good upload thank you for sharing

[@DaftOldMan]

I do shake like a jelly fish. The video makes things look better than they are.😀

Now, that's what I call extreme dedication, and curiosity. That's exactly the information I was looking for. Solved 100%!!!!! Thanks a lot for being a GENIUS.

[@DaftOldMan]

Thank you.

[@TheEmbeddedHobbyist]

if at first you don't succeed read the bloody datasheets. Why they remove the chip number and provide no data on how to use the PCB, it just goes to show the folk selling them don't have a clue what they are doing. Nice to see a datasheet being use for what it was written for.

[@DaftOldMan]

I never found this data sheet when I searched in the past. It is very useful.

[@nioubadger5740]

Hello. Thank you for this video with the wiring diagram of the chip. i have the same BMS, but i don't find how to use the thermal protection (ntc pads on the back side) i can't find the value of the NTC to connect and if there is a resistance to remove somewhere on the card to allow thermal protection via the NTC connected, it's on pin 8 for NTC and 9 for the thermal ref. have you benn able to use thermal protection of the board via an external NTC ?

[@DaftOldMan]

No I have not tried it. The explaination on the data sheet looks very complicated.

[@nioubadger5740]

@@DaftOldMan thank you. i will download the whole datasheet, i only saw schematics but did not read it. i suppose there is somewhere a 10 or 100K resistor on the board that has to be removed, like on other BMS, i'll check the board under binocular to see if there is something like that around pin 8 on the main chip

I've just watched a video confirming all that stuff, and the guy shows also a few tests with cut off IN and cut off OUT using P- and C-. He gives a very nice explanation (I couldn't understand a word, but the automatic subtitle was quite good). Here is the link: kzbin.info/www/bejne/e5nagWmbZb-XfpIsi=0G_WtlL5X7Foht-F

[@Xclerdo2]

I did all these in my battery pack but the charger always shows the battery as fully charged. What’s the problem?

[@DaftOldMan]

I would try another bms board. I bought some 4s bms from China recently and only 2 out of 5 worked.

[@ebaakiode]

Please why will 2 led indicators come on when I connect the BMS to my 3s battery

[@DaftOldMan]

That is ok. Check the three cell voltages. The two with led on should be a little higher than the other one. As they balance the led's will go out. BUT this can happen if one cell is weak compared to the other two cells so check the voltages.