BionX 37V

This battery was on an e-Bullitt bought 2012 and for some reason it does not have BionX stickers, only the bottom part had one sticker (S/N) while the other versions we’ve seen had 3-4 sticker incl BionX logos. The user had used the bike almost daily and the capacity was down to about 10-20% of the original 36V9.6AH (345,6Wh).


4 Pin XLR. Dont you even think about using anything except the original charger! “seulement” seems to be french for “only” so only use a 37V charger.

IMG_1119 IMG_1129

Only serial number is visibel beneath the locking plate. The 2+5 computer port used for discharging is one of the reasons you can not use any other type of battery.

The large positive one is not active but the smaller ones give 32-32.8V.

Two “breast”-shaped silicon bloms on both side of the battery and what seems to be a production date (2010-08-10).

Under one of the “silicon-boobies” (technical term) we found the label and the only place where the BionX logo was visible (except the BMS). Most interesting is the company name TD Energy (Founded in 2011) which is most likely the manufacturer. A Taiwanese company which also made the Smart electric Bike. However the site is not updated since 2013 so we cant tell more then that also helped develop batteries for BH, Currie and Stromer.


This battery DOES NOT use a BMS. The electronics board is mostly for “anti-tamper” purposes, sending “mixed signals” to the bike ensuring only a genuine BionX battery is connected. Of course it also monitors the voltage and has a LVC and HVC but other then that it really cant do anything else since is is not connected to the separate cells.

There are two negative wires going to the battery, the green one becomes very thin (28AWG or less) and holds ONE temp probe (later BionX batteries have 4 temp probes and a BMS).

60 Sony Konion US18650V with 1600mAh each (as new). Connected with nickelplated steel.

We upgraded this to 36V18.7ah (112% extra capacity) and also added a BMS. We let the Bionx electronics handle the discharge (like we had any choice?) but we took the negative wire directly from the charging port to BMS ensuring it would be in full control of the charging (the charger had no objection so we guess the charger can be replaced with a generic if you add a BMS.