Where are the Batteries UK

FrodoBaggins

Pedelecer
Jun 2, 2017
49
9
43
West Yorkshire
I am on to my second build.
I am adding a mid drive to a mountain bike.

I got a bit carried away and bought both a tongsheng and bafang motor. My idea was to do some comparisons on a bike and then eventually build 2 bikes.

problem I now have is the battery.
I just can’t find them anywhere. For now I just need 1.

I want something decent, 48v, downtube, branded cells and perhaps 15ah or above.
It will need to give out a decent constan flow of amps.

I read everywhere that cheap Chinese eBay batteries are awaste of time.

so where can I actually buy the batteries from.?

or is this a COVID/ brexit thing and I just have to wait.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
12,982
5,063
57
West Sx RH
Last edited:

MontyPAS

Esteemed Pedelecer
May 16, 2020
297
121
https://eclipsebikes.com/lithium-ion-c-1_8/

I've bought two batteries from them before. They are slow to reply to emails, but apart from that, are a well established and reliable vendor.
He now has a landline number on his website, better to ring and have a chat what you need.
The owner is very helpful

They sell EM3ev Shark batteries, which personally I think are some of the best!
 
  • Informative
Reactions: Fordulike

Ocsid

Esteemed Pedelecer
Aug 2, 2017
286
196
78
Hampshire
Is there currently an outright winner in the brand of cell it is best to specify the build in, for our application?
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
3,686
1,461
Tyne and Wear
Is there currently an outright winner in the brand of cell it is best to specify the build in, for our application?
I would say just stick with a major brand, LG, Panasonic, Sanyo, Samsung or Sony.

Read the specs of the particular cells used in the battery and make sure that the parallel group exceeds the maximum current you are likely to draw.

E.g. a controller rated at 30 amp maximum, will require a parallel group of 4P or more with a 10 amp rated cell. Always add a little headroom, as you don't want to be running cells at their max for too long.

Less stress on a cell equals longevity!
 
  • Useful
Reactions: Ocsid

Nealh

Esteemed Pedelecer
Aug 7, 2014
12,982
5,063
57
West Sx RH
For 18650 If high current is needed then opt for cells typically 2500 - 3000mah , if range is what you are after then current draw tends to be lower for efficiency so opt for the higher rated 3400/3500mah cells.
Larger size 20700/21700 cells are available now so there is increasing choice with this size, the Samsung 50E is looking very good with life cycle aging matching the best 18650 cells like LG MJ1 & M36. 4 x 50E cells gives 20ah with max 40a discharge.

Someone wanting both high current and range then you have to bit the bullet and opt for a larger heavy battery with more cells or carry two.
 
  • Useful
Reactions: Ocsid