bosch batteries

[filspeed]

hello,
new here.

i have a few bosch questions. i'm gonna buy an electric speed bike, probably with a bosch system.
i would like to have a big battery. something like 1500watt.
from what i have red

1)a double bosch battery cannot be added if you don't buy a bike with two batteries installed?
is this true ? i have red that you need an extra Y cable and that the display has to be capable of doing communication with extra battery... so are there situations where you can slap on an extra battery ?
2)if this is not possible with bosch products, can one alter the system DIY style to add an extra battery ?
3)i have red that one can "refill" the packs with better batteries, even with 21700 to yield more power. but some BMS would hold down the capacity because they are programmed for it ? are there specific models or production dates that don't have this problem?
4)Did anyone made a big battery (1500w) for the bosch system using a bosch bms and adding cells that have a capacity of say 10000mah...
5)could one charge the battery and at the same time drive ? it might be an option to do this.

a lot of questions just to know how to get or make a 1500w battery for a bosch system.
kind regards

 

[Vbruun]

Quick answer:

It's really hard to do.

Long answer:

As you already know, the BMS' talk to the mainboard. They are very sensitive and will permanently brick themselves as soon as they are desoldered from the battery, so there is not that much experimentation going on.

I don't have experience with retrofitting a second battery to a bosch system, so dunno on that one.

IMO the best way to proceed is to run the motor with an unoriginal controller and ditch the original batteries for an unoriginal. This is also hard.

Best of luck

 

[john61ct]

Sounds like it would be very stupid to buy a system based on Bosch.

 

[john61ct]

Is it possible to just carry say six Bosch packs with you, and just swap them out as they empty?

 

[filspeed]

thanks guys
not possible to carry 6 batteries.
in my country its illegal to drive 45km/H 28mph with something that you made yourself. so it has to be bosch, yamaha,..

well that's a lot of work to get it going: a unoriginal controller... if you could buy it of the shelf and it works great, but start designing that could be a very though process.

 

[Corrida victim]

From the Netherlands?

It's actually possible to legally drive 45km/u with a self build bike, you just gotta find a speed pedelec frame with registration. Then you want to keep the power within 20% of the original power and you'll be fine!

 

[filspeed]

one country below.
that would surprise me but i do understand why.
the homologation is for one vehicle and if you change it to much, it's not that vehicle any more... and those insurance companies are very aware of these things. in the end that's main thing why i wanna buy a speed ebike... cause my own "regular touring bike" is better then most speed ebikes, and i would slap on a e-kit...

 

[hemo]

Simply don't buy Bosch as they are anti competition based and only they can repair the motors, in fact they don't even repair your motor they swap it for supposedly another new one. Bosch are simply anti competitive if you keep the bike for two years then develop a fault after warranty ceases you are left with an expensive replacement bill.

 

[john61ct]

Sounds like the EU is making things very hard for the DIY side of the business.

Supporting large corporations, against the public interest.

FYI "a speed ebike" has no specific meaning, I guess a translation of a term used in these regulations?

This is also the first time I ever heard of "homologation".

 

[Vbruun]

What americans don't understand is that europe is civilized :wink:
That means that we can't do whatever we want and can't run whatever we want on the roads. We have 2 classes of ebikes - up to 26 km/h is the slow one, which you can build yourself.
There is also an up to 45 km/h which has to be build by a manufacturer and approved by the authorities. These you cannot change, because then they are not approved anymore.

So the DIY ebike community is not as big and it is not as centered around very fast bikes as it is in the states.


If you really want to do this, it can be done. Actually, I am working on a system right now.

What you want to do is to buy a bosch gen 2 compatible frame from ebay and a motor from ebay. The motors are of great quality and last a long time --> they are pretty cheap to buy second hand.
Then you want to get a VESC and use that to run the bike in sensorless mode. The VESC will take whatever battery you give it, so here you can buy a nice battery from China or make something yourself.

Then you of course need to build the rest of the bike.

When you have done this, you end up with an uglier, illegal version of a BOSCH speed pedelec which has much higher range. For some it is worth the time, for some it is not
For me it is mostly the experiment that is interesting. I think i will limit mine to 26 km/h to make it legal.

 

[Vbruun]

Sounds like the EU is making things very hard for the DIY side of the business.

Supporting large corporations, against the public interest.

FYI "a speed ebike" has no specific meaning, I guess a translation of a term used in these regulations?

This is also the first time I ever heard of "homologation".

Actually, EU is supporting the public interest by not letting people run around the streets on Home-built death machines

 

[Vbruun]

thanks guys
not possible to carry 6 batteries.
in my country its illegal to drive 45km/H 28mph with something that you made yourself. so it has to be bosch, yamaha,..

well that's a lot of work to get it going: a unoriginal controller... if you could buy it of the shelf and it works great, but start designing that could be a very though process.

I will gladly share my progress, when I get it working. It is not all that hard

 

[john61ct]

What you want to do is to buy a bosch gen 2 compatible frame from ebay and a motor from ebay.

Why that compatibility restriction if you aren't using anything from Bosch?

 

[Vbruun]

What you want to do is to buy a bosch gen 2 compatible frame from ebay and a motor from ebay.

Why that compatibility restriction if you aren't using anything from Bosch?

The motor is from bosch And that has physical mounts that need to fit.

 

[hemo]

In the UK many ride speed bikes/self builds illegally, enforcement is very low and most just rely on getting away with it or a ticking off if caught and possible bike confiscation. There is a process to get a self build faster bike legalised but the hoops to jump through are many and then the bike is more akin to a moped and not allowed to go where pedal bikes can go.

Getting back to Bosch not only motors but batteries are all but impossible for most to even deal with, The Gen 1 or 2 batteries can be re-celled but only if the BMS is kept live. We currently have a guy on Pedelecs forum who messed with the speed sensor and moved it and the magnet to the crank to try and fool the speed reading so he could go faster, It looks like it is a fairly new Bosch model and straight away the system has detected and error and shut down the system.
The guy has moved the sensor/magnet back to its original position and the system is still the same, the error has shut down the bike. A dealer is unable to clear the error as the system error is a tamper error and the whole bike now has to go back to Bosch to deal with it, the user may find he probably might have an expensive bill to pay if the bike comes back. Bosch are anti competitive and the German forums are quite scathing of their practices as well as problems generally with the drives, like a lot of countries the self build is still the way to go for quite a few.

 

[Herrie]

1)a double bosch battery cannot be added if you don't buy a bike with two batteries installed?
is this true ? i have red that you need an extra Y cable and that the display has to be capable of doing communication with extra battery... so are there situations where you can slap on an extra battery? I am no expert here, but I do have some experience with having an extra battery added. Word is that it would work with engines from 2018 and newer. Older engines would not work (for whatever reason, or at least that's what I've been told). Furthermore you would need to have the lastest software on your engine, display and batteries as well (your bike dealer with Bosch dongle can do this (either free of charge or they will charge you a small amount for this € 20/30 usually). You would need the Y-cable and a holder for the battery. Afterwards it should work. We added a 2nd battery this way to our 2015 Urban Arrow Family which has a newer Performance CX engine (2015 Active line had some bearing issues and it wasn't worth getting it fixed, because getting a Performance CX engine didn't cost much more v.s. revision). So I know from experience that you can retro-fit a 2nd battery.
2)if this is not possible with bosch products, can one alter the system DIY style to add an extra battery ? See above, Bosch BMS is specific to Bosch engines (CAN protocol etc), you cannot use another BMS. Theoretically, you might be able to salvage a working BMS from a Bosch battery pack that's otherwise broken and fit it with new cells. I haven't tested that. Word is that the BMS will "adjust" to the "new" capacity etc after a few charging cycles. I'm not sure what limit would be there in terms of maximum capacity that you could use.
3)i have red that one can "refill" the packs with better batteries, even with 21700 to yield more power. but some BMS would hold down the capacity because they are programmed for it ? are there specific models or production dates that don't have this problem? See above
4)Did anyone made a big battery (1500w) for the bosch system using a bosch bms and adding cells that have a capacity of say 10000mah... I haven't seen them. e-Bike Vision has some aftermarket with bigger capacity using Samsung 35E cells.
5)could one charge the battery and at the same time drive ? it might be an option to do this. Unlikely