Where/what battery to buy

tony2311

Pedelecer
Sep 23, 2014
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3
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I find my ktm bike is a bit too slow/restrcitive for my likings. i am going to convert my old bike with a befang bbs002 kit. i will be using the bike mainly for fun ride on trailsbut sometimes i can cover 30miles. I think i want a 48v 15-20ah battery. where can i buy one?
 

trex

Esteemed Pedelecer
May 15, 2011
7,703
2,669
there aren't many well known sellers for 48V batteries in the UK. I know woosh have 48V 10AH battery kits for £315.
http://wooshbikes.co.uk/?batteries#batkit
(the 48V 10AH battery kit looks very similar to the 36V 15AH, only the cells are arranged as 13S3P instead of 10S4P).
Otherwise, there's ebay:
http://www.ebay.co.uk/itm/2014-Model-48V-10-4ah-bottle-holdermount-lithium-Li-ion-electric-bike-battery-/171481578260
The woosh battery has Samsung cells and 20A discharge rate, the one on ebay have Chinese cells and 10A discharge rate.
If you only need 500W BBS02 then it may be better to buy the BBS02 36V 25A 500W rather than BBS02 48V 15A 500W, then you will have plenty of choice for sourcing 36V batteries.
 

jonathan75

Esteemed Pedelecer
Apr 24, 2013
781
206
Hertfordshire
Just as we're on the subject of batteries, I'm a bit confused between getting a 15ah 36v and a 13ah 36v which is a LOT cheaper (both have samsung or panasonic cells). This for a Bafang CST 250w kit at 201rpm (allegedly) on a 700c 13kg mtb. Am I going to get serious couloumb (drainage/battery stress/battery life) issues with running a lesser 13ah battery with the controller set at say 15a? Or is it likely to be satisfactorily resolved by dialling down the controller to 13a to look after the battery? Is there a curve of benefits accruing to a larger capacity battery, which means the 15ah is likely to not merely last 2ah longer, but have benefits somehow of a greater multiple than merely the additional 2ah? Sorry if this an incomprehensible question, not a mathematician! Thanks :)
 

trex

Esteemed Pedelecer
May 15, 2011
7,703
2,669
Batteries with Samsung cells can deliver up to 2C continuously for hill climbing. That's 26A for 13AH batteries and 30A for 15AH batteries (more than 1000W). That does not mean that your battery manufacturer are going to fit high discharge BMS automatically, you need to check the specifications or ask for high discharge BMS.
36V 13AH can support BPM CST quite adequately.
 
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tony2311

Pedelecer
Sep 23, 2014
29
3
52
Sorry i am not clue up on amps/volts
if i get the bbs002 750w 48v system from bafang. whats the best battery i should get for this kit, and where