TREK Ebike Battery Discharger

[wgriffa]

Hi I have Trek Townie with a Bosch Powerpack 400. I would like to build a battery discharger.

I have found the connector on the bike that the battery plugins into.
Bosch PowerTube Charging Socket - 100mm Cable, BDU2XX BDU3XX.
Available through Amazon from the Bosch store. https://www.amazon.ca/dp/B07G5C5MS8
The charging socket cable has 5 wires, I would love the specs that explain the purpose of each wire.

You can see the the positive and negative terminals on the battery. However simply attaching a motor to the positive and negative terminals and pressing the power buttons will not send any power to the motor.

I would like to know what signal/communications needs to sent to the battery so that I can make a battery discharger.
I found the manual for the battery, which did not help.

I an also considering getting, Bike Trainer Stand Indoor Exercise Bicycle Training Stand Magnetic Riding Stand for Mountain & Road Bike. https://www.amazon.ca/gp/product/B0876Y114X
Right now cold temperatures and snow outside prevent me from simply riding the bike till the battery level is lowered.

Any help would be appreciated.

 

[fooferdoggie]

its not going to work because the battery is waiting for a signal to turn on. usually riding it is the most practical way or taking it to a dealer.

 

[retiredNH]

INHO, you have a greater risk of damaging the battery or worse, the controller, than you do extending the battery life by discharging before storage. Keep in mind that much of the guidance on battery storage - to partially discharge the battery before long term storage - is based on soft science. It's not based on actual testing of a particular ebike battery. It's based on extrapolation from other kinds of Lion batteries. That's not, to say discharging isn't a good practice, just to say the benefits, if any, may be over-rated.

 

[tomjasz]

INHO, you have a greater risk of damaging the battery or worse, the controller, than you do extending the battery life by discharging before storage. Keep in mind that much of the guidance on battery storage - to partially discharge the battery before long term storage - is based on soft science. It's not based on actual testing of a particular ebike battery. It's based on extrapolation from other kinds of Lion batteries. That's not, to say discharging isn't a good practice, just to say the benefits, if any, may be over-rated.

Soft science? Gosh no, it's not. It's almost laughable that you would consider a fella like Jeff Dahn or Ravi Kempaiah "soft science",

Prof. Jeff Dahn, FRSC, OC
Tesla Canada Chair
Herzberg Gold medal World’s top battery scientist

But I suspect given the incredible service life of Bosch batteries they have protection circuits that manage the issues of typical batteries without the sophisticated com systems and BMS that Bosch apparently has. I'd agree and take your advice regarding discharging, but I'd want to hear from those that know more than you and I.

 

[wgriffa]

Soft science? Gosh no, it's not. It's almost laughable that you would consider a fella like Jeff Dahn or Ravi Kempaiah "soft science",

Prof. Jeff Dahn, FRSC, OC
Tesla Canada Chair
Herzberg Gold medal World’s top battery scientist

But I suspect given the incredible service life of Bosch batteries they have protection circuits that manage the issues of typical batteries without the sophisticated com systems and BMS that Bosch apparently has. I'd agree and take your advice regarding discharging, but I'd want to hear from those that know more than you and I.

I am hoping to hear from a Bosch engineer telling me the battery/controller communication requirements

 

[wgriffa]

its not going to work because the battery is waiting for a signal to turn on. usually riding it is the most practical way or taking it to a dealer.

I agree, I want to know what that signal is, and I will build a circuit to supply this signal to the battery.

 

[retiredNH]

It's "soft science" because most of the research has been done with other battery systems (i.e. not ebike) and even with ebikes, there are so many variables between/among battery systems that it's difficult to generalize across different battery systems.

The OP's hope of hearing from a Bosch engineer is an interesting one. If it were to happen, it would be a first on these forums.

 

[Ebiker01]

The ONLY OFFICIAL and NASA approved discharge method courtesy of ebiker01:

- power on the Ebike then turn it upside down , engage the PAS /throttle enabled by the user hands ; continue the activity for as long as discharge parameters are met;
- put the ebike back in it's normal upright position;
- have a glass of H2O at the end of finalizing the procedure

For exp. users ONLY :

Build a curved 90 *degree incline wall in ur backyard ; ride ebike on the "wall of ...ath"

- have a bottle of Scotch/Whisky after discharge is completed

 

[retiredNH]

Yea, upside down will do wonders for any hydraulic brakes. Just saying...

 

[fooferdoggie]

- have a bottle of Scotch/Whiskey after discharge is completed

I thought whisky caused discharge often?

 

[McCorby]

Yea, upside down will do wonders for any hydraulic brakes. Just saying...

If the brakes are properly bled (no air in the system), them being upside down will be absolutely no issue.

 

[Ebiker01]

Yea, upside down will do wonders for any hydraulic brakes. Just saying...

Try better next time and read the provided instructions !

 

[McCorby]

The ONLY OFFICIAL and NASA approved discharge method courtesy of ebiker01:

- power on the Ebike then turn it upside down , engage the PAS /throttle enabled by the user hands ; continue the activity for as long as discharge parameters are met;

Bosch no throttle, and with a good torque based system, pedaling while the rear wheel is off the ground will not engage the motor.

 

[harryS]

You could put a tap on the positive/negative leads of the battery. If it needs the bike to turn on, than do so. It might be a problem if the bike times out. Anyway, fire safety is your issue, but then you can put a load on the battery and discharge it, if that were the goal.
.
I can understand the reluctance to do this on an expensive bike. Wouldn't do it if warranty were involved.

 

[Johnny]

Hi I have Trek Townie with a Bosch Powerpack 400. I would like to build a battery discharger.

I have found the connector on the bike that the battery plugins into.
Bosch PowerTube Charging Socket - 100mm Cable, BDU2XX BDU3XX.
Available through Amazon from the Bosch store. https://www.amazon.ca/dp/B07G5C5MS8
The charging socket cable has 5 wires, I would love the specs that explain the purpose of each wire.

You can see the the positive and negative terminals on the battery. However simply attaching a motor to the positive and negative terminals and pressing the power buttons will not send any power to the motor.

I would like to know what signal/communications needs to sent to the battery so that I can make a battery discharger.
I found the manual for the battery, which did not help.

I an also considering getting, Bike Trainer Stand Indoor Exercise Bicycle Training Stand Magnetic Riding Stand for Mountain & Road Bike. https://www.amazon.ca/gp/product/B0876Y114X
Right now cold temperatures and snow outside prevent me from simply riding the bike till the battery level is lowered.

Any help would be appreciated.

I am not endorsing it, do it at your own risk.
No encryption or special comms needed, you can also 3d print your own adapter. You can find videos such as this one which pretty much gives all the info you need.

Any trainer should work it is about your wheel and tires. If for some reason you want support (why would you on a trainer?) get one that does not require you to take the wheel out.

That being said if you buy a wheel based trainer like a Wahoo Kckr Snap, on which you can turn on support then you can simply use it to discharge your battery too.

 

[Ebiker01]

Bosch no throttle, and with a good torque based system, pedaling while the rear wheel is off the ground will not engage the motor.

Once u engage the pedals and select the PAS mode , the torque translate to to the resistance felt when "rowing "the cranks.

Pas 1 : light resistance, easy rowing

 

[fooferdoggie]

Once u engage the pedals and select the PAS mode , the torque translate to to the resistance felt when "rowing "the cranks.

Pas 1 : light resistance, easy rowing

5 hours later you may've knocked the battery down to 80%

 

[McCorby]

Once u engage the pedals and select the PAS mode , the torque translate to to the resistance felt when "rowing "the cranks.

Pas 1 : light resistance, easy rowing

Nope, not with Bosch, Shimano or Brose. You can pedal to your hearts content, but the motor will not engage without a real/significant load.

 

[Ebiker01]

Nope, not with Bosch, Shimano or Brose. You can pedal to your hearts content, but the motor will not engage without a real/significant load.

well , i know very well what i don't know which is this mid motors in particular, but where do they have the TQ sensor located ?
I haven't tried this other ide on my hub motor ebike , but what would happen if one removes the TQ sensor from a mid motor ebike and tries pedalling ? I'm assuming it's easy to remove just as it is on a hub motor, m0st likely it is not.

If not, indoor trainer is the only solution and good luck to the OP in hamstering away the xtra li-ions !!

 

[fooferdoggie]

well , i know very well what i don't know which is this mid motors in particular, but where do they have the TQ sensor located ?
I haven't tried this other ide on my hub motor ebike , but what would happen if one removes the TQ sensor from a mid motor ebike and tries pedalling ? I'm assuming it's easy to remove just as it is on a hub motor, m0st likely it is not.

If not, indoor trainer is the only solution and good luck to the OP in hamstering away the xtra li-ions !!

its built into the motor. you cant remove it.