INWO's drop-in BMS kit for Samsung SDI 22s 94ah li-ion packs

I just installed Dave’s (@Inwo) “drop-in” BMS kit for the Samsung 22s SDI packs on a pack going to another forum member.

It’s a super simple install, hardly any tools needed. A little bit of electrical knowledge and a decent working multi-meter make this a snap, but not even that is required IMO.

Won’t even need to take the battery pack out of the box.

Open up the shipping box, locate the single #2 Philips screw on the pack cover. Remove the screw and set aside.


Locate the spring tabs

With a couple thin blades, standard screwdrivers, slim jims, etc. Start at the “back” (opposite end from the battery connectors) , press in the spring tabs to release the cover and work your way around the side closest to you. First 2 will be a pain, after that the cover will come up easy.

Impressive build quality from Samsung.

Remove the circuit board on the right and discard.
It’s just clipped in on the sides and the wire connectors will just pull free

Locate B0 and follow the wire back to the connectors

The larger connector going to the JK BMS is B- and then B0. Connect the end with the adapter to the SDI pack lining up the black wires.

Attaching 2nd adapter cable. This one will have the smaller BMS connector on the other end.

Run the BMS wires out the com port connecter holes from the old Samsung BMS.
Kapton tape optional. Since this pack is leaving my possession, and I had the tape, I wanted to make sure the chances of something working it’s way loose are minimal at best.


Reinstall lid, install phillips crew from step 1. Run balance leads through depression in lid, test fit BMS above the leads. Test the pinouts on the leads for proper order, voltage and location.

Connect balance leads to BMS, power up by touching 9v battery to 9V connector ( a little hard to see, on the “right” towards the end of BMS / end of the battery pack, suspended above the BMS ). Connect B- and done.

Log into JKBMS app and set parameters as appropriate.

Took me longer to photograph, transfer, resize, write this and insert the photos than it did to install the adapter kit.

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