10S4P with Samsung 29E vs 10S5P with Samsung 26H

kilou

10 W
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Aug 25, 2014
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Hi,

I'm about to buy a new battery pack for my Bosch ebike. My ebike is 36V with a 350W nominal motor. However afaik the motor can draw up to 540W peak. Not sure whether this is exact but I guess that max amperage should always be <18A anyway.

I'm considering two different packs:

- 10S4P made with Samsung 29E cells (400Wh) (original Bosch)
- 10S5P made with Samsung 26H cells (468Wh) (compatible aftermarket replacement)

Obviously cell capacities are different but the number of parallel cells compensate for that, so that the pack with 26H cells has a slightly larger capacity compared to the one with 29E cells.

Both packs come at about the same price (10$ difference) so price is not a factor. I'm mostly interested in cycle life, reliability and range. The 29E cell has a max discharge of 8.25A so in a 4P pack, that's 33A. The 26H has a max discharge rate of only 5.2A but in a 5P pack that's 26A. So both pack would be sufficient for my needs but the 29E pack appears superior in term of max discharge rate. On the other hand, if we consider my actual needs (say 18A discharge), the 29E cells in the 4P pack would be discharged at 1.55C while the 26H cells in the 5P pack would be discharged at 1.38C. So in theory, the load is slightly smaller for the 26H pack (which could translate in longer cycle life??) although the difference is small.

Which of these 2 packs would you recommend and why? Are these minor differences in discharge capacities meaningful at all in real life? The second pack (468Wh) has more capacity but I wouldn't favor that if this comes with a lower cycle life. My current pack is the 400Wh (original Bosch) and it is almost 8 years old and still working fine (although its power lags a bit obviously). Thanks for your suggestions!
 
Purely in the abstract I reckon the cells rated for a much higher C-rate will have better longevity

even if their discharge rate will be a little higher.

Ideally you could google for actual real-life testing results from trusted forum members.

Likely not a huge difference.

That is if you are equally certain of genuine new Grade A provenance.
 
Thanks! Then I think I'll stick with the original Bosch 400Wh since I've been extremely happy with the cycle life of my pack (8 years and about 30'000km). Another advantage is that being a 4P, it is slighlty lighter than a 5P. Having more range would be great but I doubt that going from 400 to 468Wh would make a big difference in real life. I'll have to look for other options (e.g. extender battery) if more range is important.

Thanks!
 
Who is the vendor of the unoriginal pack? I am really surprised that someone wants to sell such crappy sells at bosch prices.
 
I've found the 29E cells to be incredibly tough with long cycle life.
 
A new moderator?
 
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