36V 10ah ebike battery pack. from 2600mah to 5000mah - any concerns?

[john_77]

Hi there.

-my ebike specs are: 250W, 36V, 15A cutoff by controller.
-my current battery pack is: 18650 2600mah cells (5A rated), 3.6V, 10S4P
-I'm thinking about switching to this configuration for my next pack: 21700 5000mah cells (10A rated) ,3.6V, 10S2P

I am asking for your advice:
I am aware that there will be a minor difference in capacity (10.4ah to 10ah).
apart from that, do you have any concerns about the 5000mah 10S2P setup or should that be fine?
Many thanks for your input! Highly appreciated
John

 

[goatman]

depends on the 21700 cell
15amp controller from a 2p battery means 7.5amps per cell

i think most 5000mah 21700 dont like more than 5amps for cycle life

 

[john61ct]

Yes in the theoretical abstract no problem.

But with completely different quality and chemistry cells

performance will be completely different, one way or the other.

If you need power density rather than energy density, and longevity most of all

check out A123's 26650

Otherwise Samsung 50E for high energy density and Samsung 40T for high power shorter life

Molicel P42A ?

 

[flippy]

i would change the batteries to something like the 25R. there is nothing to gain from going to the bigger cells.
the 25R means it can keep going without sagging at full load so it gives you are much nicer and flatter performance curve over the entire range of the pack. the 25R will also outlast the bigger cells by a considerable margin.

 

[bobbill]

Me know squat, however, Flippy, seems to get it right.
Wasted stuff...!