Low Battery Cutout for Bosch Gen4?

E14Delite

Member
Not sure whether the motor cutout on low battery is set by the bike manufacturer or whether related to the Bosch motor/battery control software.

I have an R&M delite Gen 4 with Rohloff hub and I understand the motor cutout is programmed to leave about 2 hours of lights and eshift capability. The motor currently seems to cut out at about 10% battery capacity irrespective of whether the lights are in use or not.

My question is it possible to say change the setup for the motor cutout around a 5% figure rather than 10%? Is this something that a dealer might be able to change?

Thanks Stephen.
 

Chris Nolte

Well-Known Member
This is not an option at the dealer level at the moment, but it might change in the near future. To my understanding Bosch is working on making this available.
 

E14Delite

Member
This is not an option at the dealer level at the moment, but it might change in the near future. To my understanding Bosch is working on making this available.
Thanks for the answer Chris. Sometimes helpful to be able to access a few extra kilometers. Perhaps some at Bosch might remember the early model VW beetles where there was a supplementary fuel tank you could switch over when the main ran out. Not sure if this made it to the US but certainly downunder.
Cheers Stephen
 

rich c

Well-Known Member
Is your "seems to cut out at about 10% battery capacity" a measured figure or some type of guess?
 

E14Delite

Member
Thanks for the answer Chris. Sometimes helpful to be able to access a few extra kilometers. Perhaps some at Bosch might remember the early model VW beetles where there was a supplementary fuel tank you could switch over when the main ran out. Not sure if this made it to the US but certainly downunder.
Cheers Stephen
Hi Chris,

Thanks for the video on the Bosch Gen4 Software upgrades coming.

Do you know if this upgrade includes a limp home mode so perhaps motor will run to 5% battery charge. Perhaps in conjunction when battery gets to 1%-2% rohloff gear selection defaults to that gear specified as starting gear on stopping. This would allow you to reset this gear to best gear to get home if no motor power. Maybe an idea for Bosch??

Cheers from downunder, stay safe, wear a mask whether you are red or blue.
 

Chris Nolte

Well-Known Member
Hi Chris,

Thanks for the video on the Bosch Gen4 Software upgrades coming.

Do you know if this upgrade includes a limp home mode so perhaps motor will run to 5% battery charge. Perhaps in conjunction when battery gets to 1%-2% rohloff gear selection defaults to that gear specified as starting gear on stopping. This would allow you to reset this gear to best gear to get home if no motor power. Maybe an idea for Bosch??

Cheers from downunder, stay safe, wear a mask whether you are red or blue.
The bike will keep power for lights and E-14 but not to give limp mode. You’ll be on your own there
 

Chris Nolte

Well-Known Member
Just thinking this could perhaps be considered as a future software upgrade. Even having an extra 5% in eco might get you home. Cheers
I’ll bring it up when I get a chance. I certainly give them a lot of suggestions. Welcomed or otherwise
 

E14Delite

Member
I would hope Bosch would welcome all your suggestions whether viable or not. Very beneficial for a company to have input from someone having first hand knowledge of a large customer/user base and no doubt you can do this without being their FB friend.☺☺☺☺
 
Not sure whether the motor cutout on low battery is set by the bike manufacturer or whether related to the Bosch motor/battery control software.

I have an R&M delite Gen 4 with Rohloff hub and I understand the motor cutout is programmed to leave about 2 hours of lights and eshift capability. The motor currently seems to cut out at about 10% battery capacity irrespective of whether the lights are in use or not.

My question is it possible to say change the setup for the motor cutout around a 5% figure rather than 10%? Is this something that a dealer might be able to change?

Thanks Stephen.
Hello!

There is an option to select the power (in watts) that your lights receive during the ~2 hour period. You can choose values between 3 and 18 watts. Determine what your lights are rated at, and set the value at or below that so that you are not saving extra energy. The Drive Unit will save the ~2 hours of lights @ X watts regardless of whether or not your lights are actually turned on. The only way to disable the 2 hour buffer is to disable lights in the Diagnostic Software (this tells the Drive Unit that there are no lights installed.)

The eShift will stay what it is because it is part of the software package for that eBike.

I'm not sure how adjusting the reserve light power will affect the exact percentages you referred to. I think it's likely that the percentage you see is showing available capacity, outside of the reserve. For example, 10% remaining would mean you consumed 90%, so with lights disabled, that 90% would technically represent more capacity. I'm actually not completely sure on this part, but I will look into it. In anycase, you should see slightly improved range with lights disabled, or with a lower reserve wattage selected.

I don't think this is what you were asking, but it's worth mentioning as an FYI for anyone else reading... Outside of the lights adjustment, it is not good practice to try to get lithium batteries to go lower on their preset reserve. All lithium tech that I know of cannot be safely charged once it hits a minimum voltage, and you risk ruining a battery as chargers are designed not to start charging below a certain voltage.
 
Last edited:

E14Delite

Member
Hello William,
Good to see your contribution to the forum as technical information on behalf of the manufacturer is much appreciated.
Some points:-

a) Is the light power selection a user option or requires dealer input.

b) I have been doing some range calculations on a standard route based on assist settings so will look at this with lights on/lights off which may give some indication of whether the remaining range is influenced by setting. I would however think the battery percentage indicated is independent of power settings.

c) Your comment about minimum cutoff value is relevant. Is the system calibrated so that the minimum cutoff value is indicated at 10% or 0%? I would assume that as 2 hours of lights/eshift is still available you may not be adversely affecting the battery if 1 hour of that power was available for "limp home mode"

d) Is Bosch able to make available a power curve for the Gen4 motor. Obviously this will be different with the new software upgrade coming. It would be helpful if Bosch could publish a power curve rather than leaving it to a 3rd party as knowing this information would be good for optimum cadence/gear selection.

Regards from downunder.
Stephen
 
Hi Stephen,

a) The dealer will have to adjust this for you using their Bosch Software.

b) Keep in mind the lights will have to be disabled or the "emergency reserve" adjusted in order to see a range difference. Just turning lights off from display won't have affect the range. I asked a question about battery percentage this morning, I'll update once I get an answer.

c) The answer to the 10% or 0% question should hopefully arrive with the second part of the previous question above. Regardless of what gets figured out with percentage display, etc., the Bosch system will always cut itself off with the same amount of voltage buffer. There is no way for the user to modify this safety buffer without some sort of unsanctioned hack, etc. For example, whether you have lights enabled and eShift on, or just plain eBike with nothing else, the low-voltage cut-off will always be approx. X volts (exact value unknown to me.) Even the 2 hour light buffer is designed to keep you above that X voltage level. I feel like I'm not explaining this well, so feel free to request clarification. 🙂

d) I'm not sure if we have a public version of this. I'll take a look. Bosch tends to keep everything very simple for consumers, and rather than publish complicated charts, they just provide suggestions like, "most efficient operation is at a pedaling cadence of approx. 70-90 rpm, or a minimum of at least 50 rpm."
 

webcurl

Active Member
I asked a question about battery percentage this morning, I'll update once I get an answer.
Hi, i'm curious to know approximately how many gear changes you could get via E14 with 5-10% or whatever left of 500/1000Wh.
I'm sure Rohloff & Bosch worked this rough figure out at some stage.
Reason i ask is in a scenario whilst touring out in the middle of nowhere and you've exhausted the batteries and don't have an option to charge for a day or 2. Not being able to shift gears for a day or 2 whilst trying to pedal manually to get somewhere to charge would be a nightmare! Manual shift, non E14 would be an advantage here.
 
Hi, i'm curious to know approximately how many gear changes you could get via E14 with 5-10% or whatever left of 500/1000Wh.
I'm sure Rohloff & Bosch worked this rough figure out at some stage.
Reason i ask is in a scenario whilst touring out in the middle of nowhere and you've exhausted the batteries and don't have an option to charge for a day or 2. Not being able to shift gears for a day or 2 whilst trying to pedal manually to get somewhere to charge would be a nightmare! Manual shift, non E14 would be an advantage here.
Depending upon the specific eShift System, Bosch states approx. 50-100 gear changes. This number is accurate regardless of battery capacity (400/500/625, or Dual Battery configs.) Both with eShift and the lights that were discussed previously, the system is not really working off of a preset percentage as much as it is working with a specified amount of actions and a specified time period. In other words, it's "thinking" that it needs to save enough capacity for 50-100 shifts, and 2 hours of lights at X watts. It'll stop delivering Drive Unit assistance once it's reached the point where it can just deliver the eShifts and 2 hours of lights (and of course stay above the low-voltage threshold.)

Pedaling a heavy eBike without assistance and without the ability to shift would be rough!!!

Still waiting on an answer from Germany regarding displayed battery percentage at Drive Unit cut-off, aka the start of reserve light and eShift power.
 

webcurl

Active Member
Depending upon the specific eShift System, Bosch states approx. 50-100 gear changes. This number is accurate regardless of battery capacity (400/500/625, or Dual Battery configs.)

Pedaling a heavy eBike without assistance and without the ability to shift would be rough!!!
Thanks!
It's rough pedaling my R&M Gen2 CX without additional gear and assistance as it is :)
As i suspected i think my next R&M/Like ebike would be extra expensive as i'll have to swap out the E14 for manual shift (realize E14 would have to be disabled by dealer).
Unless it's impossible to do.
No offense to the work Rohloff/Bosch have done with E14, i'm sure i'd love it everywhere else except for extended touring.
 
You're welcome!

I've never had the chance to ride the Rohloff/Bosch eShift combo, but I'd imagine it is quite nice!

… assuming you have a charging outlet waiting for you at the end of the ride. :)