Yamaha hacking dongle to use 3rd party batteries


100 W
Oct 2, 2010
Maastricht, The Netherlands
Yamaha PW series mid-drive motor hacking dongle to use 3rd party batteries

Please post your questions about the Yamaha dongle here.

See the full article: https://www.avdweb.nl/solar-bike/batteries/battery-hack
As with other brands, the Yamaha PW series motor doesn't allow to use any 3e party battery. But with the use of the dongle described here, the Yamaha ebike will be hacked so that you can use any battery instead of the original expensive Yamaha battery.

This are the most important characteristics of the Yamaha battery dongle:
  • You can use any battery on your Yamaha ebike instead of an expensive original Yamaha battery.
  • The battery capacity is measured very accurately with an LTC2944 fuel gauge IC, not just simple voltage measuring.
  • The battery capacity is stored in an EEPROM so that it is not lost when switched off.
Promising great job... looking forward testing it :D
Is there a plan ta have it adapted to Giant bicyles soon ?
i have already used 2 of these, made by a forum members in the german pedelec forum.I hope yours are working with yamaha 2016, 2017 models as well?
What about the Giant?

Hi avandalen,

I was wondering if there is any news on the dongle, I have a very young Yamaha battery and the BMS has stopped working, I can't use a third party BMS because of the protection so I would have to use one of these dongles

Hi avandalen;

I have a Winora radius equiped with a Yamaha pw and 36v pasb2 yamaha battery, i'm interested in your dongle when you have them available again, saw the notice on your website that they are currently out of stock, please let me know once you have them again, as i want to make a new battery with more range.

I have a 2016/2017 Giant Explore E+ withe a Yamaha PW motor. It uses a the 3 wire setup: pos/neg/grey
Until I can order one of these dongles, I am curious to what other battery options are out there that would mimic the Giant battery.
I cannot locate a in frame Giant battery for this particular model.


Thanks for your dongle article.
Questions to your article.
1) Is it only the battery that sends communication on the data line?
2) If I have a original Yamaha battery. Is it enough to make the data line constant 5V to make the battery keep the power on?

Best Regards
This is the first I've read about Yamaha locking users into their batteries.
This makes me even happier with my TSDZ2 mid-drive. I can use any 52V battery pack I want. :thumb:
Hi avandalen,

Congratulations on achieving what is certainly on the minds of many - making oem ebike run proper battery,
If the dongles were available, I would certainly start a project of refurbishing yamaha powered bike. Is there any chance the dongles are available again? Any timeframe for that?

best regards,
Hello and congratulations on your efforts! Can I buy such a key from somewhere? I think there will be a lot of interest if they appear on the market.
A few notes from first days of operation. (with stock cells from 400wh 2016 pack, 1000kms use since new March 2023)

- One-button menu system is easier to use than I expected. Intervals between changes are generous and the manual description is accurate and complete. (that being said, I would very much like to use the USB port to program directly, if possible, especially for easy verification, but this is personal preference only)

- Setting capacity to 11 Ah and comparing with DALY 40A common port bluetooth BMS on first discharge I ended my ride today at 46% capacity on the Yamaha display and 43% on the DALY BMS. I consider this to be an accurate enough calibration. It may also be relevant to the state of health of my pack, remaining capacity appears to be only insignificantly diminished.

- When charging from 46% after the ride, the dongle went into power saving mode after motor control timeout. Powering on the Yamaha during charging, the indicator remained at 46% during the entire charge.

- When the BMS opened the FET at the 42V cut off and indicated 100% charge, I powered on the Yamaha and the display initially indicated 46%. After a moment, the dongle recognized the full-charge cut-off voltage, I assume, and the Yamaha display and dongle bar graph both indicated 100%. I can live with that - I am charging at 2A currently and have no need to charge to less than 100% - I have time.

I appreciate the lack of parasitic draw in the stock configuration and will likely not bridge the bypass jumper.

Thanks again, Albert
thank you for developing this dongle.
in your diagram in the assembly manual, I would like to be sure I understand. If I have a BMS with the negative charging port different from the power négative output, is it a dualport battery? otherwise the bms with the same connection for charging and power output is it single port?
can we use a standard charger?
I’m going to install everything inside the battery and remove the sleep mode, is this a problem?
What a FABULOUS bit of engineering - Well done Avandalen, well done! Installed this inside the case of a 3rd party battery (Green Cell) - it works perfectly so far.