New Bosch PowerTube 750Wh 2022

2WheelsNot4

E*POWAH Master
Oct 17, 2021
917
711
Scotland
Basically asking - can you remove your 625w battery and replace it with this one ?

Or is it too big, too long, too fat or something else.
I'm kind of hoping they've just managed to increase the power in the already existing system, but I've a feeling its not going to fit or there will be far more to it.
I dont think the stats for these are in yet anyhow, and nobody has asked or said if it will fit or not.
 

Bigtuna00

Active member
Nov 27, 2019
556
337
CA
The PowerTube 750 battery has more cells. The package is pretty much the same, just longer. However regardless of whether or not the battery would fit your bike, it's not compatible with any previous system. You must have the new motor, new controller, and new Kiox to go along with the new battery.

 

2WheelsNot4

E*POWAH Master
Oct 17, 2021
917
711
Scotland
That’s a bit of a pisser…………
And a tad nonsensical. The motor would operate whatever powersouce it was put to use with.

It seems to be the thing these days, not to make anything compatible with previous or earlier products.

That said though. If its longer than some adaptation to the battery mounts could be made inside the frame. The area the battery lives hasnt increased, they've just moved the connectors to widen the gap a little. And as theres no through frame bolts/nuts/screws then i suppose it is something that could be done later
 

Hamina

E*POWAH Master
Mar 22, 2020
500
396
FIN
Frame battery sizes:
Bosch 625w 416 x 84 x 65 mm
Bosch 750w 484 x 84 x 65 mm


maybe have a look at your frame and measure if there's room and make world's first retrofit for the CX Gen4 or why not upgrade the existing system to dual battery if the need is real?
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,832
6,842
UK
Of the three ebikes I've owned, the scope for moving the battery brackets has been very limited. The motor is a constraint at one end & the locking mechanism, especially those with holes in the downtube for keys at the other gives next to no wriggle room.
 

Mteam

E*POWAH Elite
Aug 3, 2020
1,864
1,801
gone
Of the three ebikes I've owned, the scope for moving the battery brackets has been very limited. The motor is a constraint at one end & the locking mechanism, especially those with holes in the downtube for keys at the other gives next to no wriggle room.
If there was space in the frame you could easily drill a new hole for the key - although that would obviously void the warranty on the frame, but Iguess you'd be getting into warranty voiding territory just by using a non supported battery
 

Doomanic

🛠️Wrecker🛠️
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Founding Member
Jan 21, 2018
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You need new everything to run a 750 battery so you might as well sell up and buy new.
 

1oldfart

Active member
Oct 6, 2019
684
321
Outdoors
And a year later it will be new battery density so you are pedaling on a cell phone . . . rent a new one every 2 years !
Now you know why they call tem smart phones, they turned consumers into dummies.
 

2WheelsNot4

E*POWAH Master
Oct 17, 2021
917
711
Scotland
Frame battery sizes:
Bosch 625w 416 x 84 x 65 mm
Bosch 750w 484 x 84 x 65 mm


maybe have a look at your frame and measure if there's room and make world's first retrofit for the CX Gen4 or why not upgrade the existing system to dual battery if the need is real?
The need isnt real or today, or likely even in the next couple of years. But in the coming years batteries are going to get bigger, and the standard today of 625w might not be as available as it is now. I was thinking if there was little difference there would be scope to increase the range simply by fitting a bigger battery.
Given the difference between the 625 and the 750 is close to 3", thats never going to be an option, not unless they figure out how to pack more power into a smaller package.

Currently like everyone else, should a real need arise, there's always an extender battery option.
 

Rusty

E*POWAH BOSS
Jul 17, 2019
1,513
1,673
New Zealand
The thing that pisses me off is that if they changed the cell type they could have made it the same length to allow retro-fitting.
 

Sherman

Active member
May 9, 2018
252
463
3rd Rock
The thing that pisses me off is that if they changed the cell type they could have made it the same length to allow retro-fitting.

Probably not. 21700 cells are 5mm longer than 18650 cells. So if the frame is not designed to take batteries with 21700 cells (like Specialized frames) then retro-fitting is most likely not possible.
 

Rusty

E*POWAH BOSS
Jul 17, 2019
1,513
1,673
New Zealand
Probably not. 21700 cells are 5mm longer than 18650 cells. So if the frame is not designed to take batteries with 21700 cells (like Specialized frames) then retro-fitting is most likely not possible.
Maybe - maybe not. We got a new battery back for our 18v Bosch drill at work and the new Core 4.0 Ah battery is lighter than the old one looks smaller. Waiting for the boss to bring the old battery back so I can compare. According to our propellorhead the longer, but narrower form factor allows for more efficient packing and usage. Need to pull the old one apart and take a looksie, but comparing the cells on the benchtop I can see Bosch using them and fitting in the current form factor. Don't really care about Spesh.
 

HowardM

New Member
Jan 5, 2022
9
4
Chesterfield
As far as I’m aware the main reason you can’t retro fit the new battery is all the wiring and plugs have changed. It is a pisser on one hand but in order for the huge new battery to be shoe horned into a frame Bosch have had to repackage everything.
I’m not 100% sure yet but I think the new wiring design will allow you to remove things like head units without having to uncover or drop motors. Looking forward to that!
 

Doomanic

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Patreon
Founding Member
Jan 21, 2018
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According to our propellorhead the longer, but narrower form factor allows for more efficient packing and usage.
Your propellorhead needs to reacquaint himself with cell specifications. The first two numbers are the diameter and the second two are the length.
 

Chris ledger

Active member
Aug 17, 2021
447
246
Rotherham
As far as I’m aware the main reason you can’t retro fit the new battery is all the wiring and plugs have changed. It is a pisser on one hand but in order for the huge new battery to be shoe horned into a frame Bosch have had to repackage everything.
I’m not 100% sure yet but I think the new wiring design will allow you to remove things like head units without having to uncover or drop motors. Looking forward to that!
I was told other things are coming on the new system things like option to fit heated gloves etc
 

1oldfart

Active member
Oct 6, 2019
684
321
Outdoors
It is like when they started Fats with 27.5 wheels just so older pieces do not fit anymore.
They sell more bikes, more parts and $$$$$$$$$$$$$$$ youpppiiiiiii
 

stiv674

E*POWAH Elite
Mar 4, 2019
777
600
Wiltshire
Your propellorhead needs to reacquaint himself with cell specifications. The first two numbers are the diameter and the second two are the length.

This ^^ so if there's currently five 18650s arranged two on top of three (x10) then the extra diameter of the 21700s wouldn't fit that way either.
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,526
5,004
Weymouth
The Cube Stereo fitted with the 750w/h battery has had a frame re-design. Top tube is straighter, down tube is longer, knock block fitted to the headset.
 

Rusty

E*POWAH BOSS
Jul 17, 2019
1,513
1,673
New Zealand
Your propellorhead needs to reacquaint himself with cell specifications. The first two numbers are the diameter and the second two are the length.
And?
Since if one is going for equal capacity one can use 33% fewer cells then one gets a smaller overall package. To use the existing package which is 80 x 60 x 410 (approx size) I would expect the 625Wh Bosch powertube could be 700 - 725Wh. Really depends on how they pack and the controller circuitry I am thinking. The thing Karl tells me is that with fewer cells it reduces the size, complexity & cost of the BMS required as well as the cost of cells.

I just see BS with ebikes that is really more about wank factor and one-upsmanship amongst the manufacturers. To be fair, that pretty much applies to anything bicycle related once you get away from the bottom of the line units. Better if they spec ebikes and eMTB appropriately - 4 pot brakes and 9 or 10 speed running gear - let the riders put on underspecced components if they wish.

That of course was slightly off subject, but does kind of cover the way they are turning ebikes into cellphones.

All of course MY opinion - you and everyone is entitled to their own opinion.
 

1oldfart

Active member
Oct 6, 2019
684
321
Outdoors
And?
Since if one is going for equal capacity one can use 33% fewer cells then one gets a smaller overall package. To use the existing package which is 80 x 60 x 410 (approx size) I would expect the 625Wh Bosch powertube could be 700 - 725Wh. Really depends on how they pack and the controller circuitry I am thinking. The thing Karl tells me is that with fewer cells it reduces the size, complexity & cost of the BMS required as well as the cost of cells.

I just see BS with ebikes that is really more about wank factor and one-upsmanship amongst the manufacturers. To be fair, that pretty much applies to anything bicycle related once you get away from the bottom of the line units. Better if they spec ebikes and eMTB appropriately - 4 pot brakes and 9 or 10 speed running gear - let the riders put on underspecced components if they wish.

That of course was slightly off subject, but does kind of cover the way they are turning ebikes into cellphones.

All of course MY opinion - you and everyone is entitled to their own opinion.
This is what i am seeing. In a shop probably 2-3 months ago i was killing time while they do a quick repair on my Ebike.
So i looked the price tag of a Trek city Ebike. It was fucking 10,000$ and it almost looked like a 1,100$ bike from 3 years ago.
It is shocking all the shit being sold while overpriced.
Just do a search, there are millions of posts from riders, displeased from their ***great seatpost*** asking is one lasting?
Is one working in the cold? Just more $$$ more weight and more complaints.
I will not name companies but some Esystems sold in the last 6 years were not
ready. I would turn crazy needing a third waranty claim in the first year.
Having my bike spending more time not being available to ride.
Lucky me my 10S Ebike only needs tires, chains ... and keeps on riding
 

Doomanic

🛠️Wrecker🛠️
Patreon
Founding Member
Jan 21, 2018
8,702
10,342
UK
And?
Since if one is going for equal capacity one can use 33% fewer cells then one gets a smaller overall package. To use the existing package which is 80 x 60 x 410 (approx size) I would expect the 625Wh Bosch powertube could be 700 - 725Wh. Really depends on how they pack and the controller circuitry I am thinking. The thing Karl tells me is that with fewer cells it reduces the size, complexity & cost of the BMS required as well as the cost of cells.
It's not that simple.

There are certain constants based on current motors. To get the pack voltage you use banks of 10 cells in series. To get the capacity you join these banks in parallel. I did some maths today and knocked up a little spreadsheet using information from the internet with regards to weight and capacity.

image001 (3).png


Notes;
The weights shown are for cells only, no BMS, cables or casing and for comparison purposes only.
The large numbers on the same line as the cell dimensions are the size of the pack in cm2 (yes, I know I spelt pi wrong... )
As far as I know, the largest commercially available 18650 is 3.5Ah, the largest 21700 is 5Ah. The sells used in the Spesh 700Wh battery are approximately 4.7Ah.
In every instance, there is a size and weight penalty to using 21700 cells.
 

Waynemarlow

E*POWAH Master
Dec 6, 2019
1,106
888
Bucks
In every instance, there is a size and weight penalty to using 21700 cells.
Sort of, the 18650 cells were designed as the optimum use of space to obtain maximum power density in the cell technology of its time, too big a diameter and they are not as efficient, to long and they charge slower. Later battery technologies seem to have over come this a bit. One only has to build a few packs of 18650 to see how the cells almost sit perfectly in their neighbours circumference unlike the 21700's which seem to leave small voids.

What you do need to consider is the 48 volt units now coming through where its 13S, as in banks of 13 batteries in series. Here you can get 13S3P 21700's giving about 720W/hs in well under 3kg's, lots less numbers of cells means less welding, less nickel strip less factory storage, less shipping and less over all cost with more efficient motors ( well in theory ) giving more range ( less amps through the motor means smaller wires and less heat loss ).

Now lets talk 52 volts and even 70 volts where all the motor nerds are playing.
 
Last edited:

stiv674

E*POWAH Elite
Mar 4, 2019
777
600
Wiltshire
It's not that simple.

There are certain constants based on current motors. To get the pack voltage you use banks of 10 cells in series. To get the capacity you join these banks in parallel. I did some maths today and knocked up a little spreadsheet using information from the internet with regards to weight and capacity.

View attachment 79683

Notes;
The weights shown are for cells only, no BMS, cables or casing and for comparison purposes only.
The large numbers on the same line as the cell dimensions are the size of the pack in cm2 (yes, I know I spelt pi wrong... )
As far as I know, the largest commercially available 18650 is 3.5Ah, the largest 21700 is 5Ah. The sells used in the Spesh 700Wh battery are approximately 4.7Ah.
In every instance, there is a size and weight penalty to using 21700 cells.

mmm-pie-pie.gif
 

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