Battery inquiry

Frogslayer

Active Member
Joined
Jan 20, 2019
Messages
484
Hi guys, I have a china girl moped and was considering making my wife's bike into an Ebike. I can find all types of controllers and motors but the batteries are twice the cost of the hardware. So what batteries are you guys running and what are my options? Thanks in advance.
 


FurryOnTheInside

Well-Known Member
Joined
Sep 23, 2013
Messages
3,425
Cheap used one, 36v 11Ah, came with a used front wheel geared hub motor kit I bought on ebay.
The used kit is the 26" version of the 700c kit I just got new (without a battery). I only intend to use the 26" bike and old battery for short trips to town or to "the point". That's why I didn't mind buying a used battery (it was essentially a free battery because the motor wheel and controller are as good as new).
I haven't built the kit onto the bike and tested it yet. Waiting for an injury to heal. :(

I can use the same battery in the nice 700c hybrid bike too if I need to before I finish saving up for a really good battery for it (and decide what I actually want).

I'm now looking into the VRUZEND no weld cell connectors for making my own 48v pack from 18650 cells for the good bike.
With no welds I can open up my battery to test individual cells internal resistance and replace the first cell that goes bad, thus extending the life of the pack, relative to a spot welded pack that would need to be sent away for much more difficult and expensive refurbishment..
But I need to know what BMS to get and how to wire it all up.
It will hopefully be a bit less expensive than having to pay someone else to spot weld and wire a custom pack for me with the same cells, and it will be user serviceable. :)
If they made one for the 21700 cell type I'd be happier.. Fewer cells, fewer parallel connections needed for the equivalent Wh / Ah.
 

bakaneko

Well-Known Member
Joined
Nov 16, 2015
Messages
1,210
I use the 36V 4.4aH lithium ion scooter battery packs from eBay. They are great starter battery. I don't know what range or pedal assistance for your wife. But, four of these will provide decent range in 36V or 72V configuration. They sell for 33-44$ a pack on eBay USA. I have 8 of these for about 25 miles hard riding and 40 miles with pedaling and slower speeds. Search "36V 4.4aH battery" in eBay search bar. Again, these are old cell tech and good starter batteries not performance ones.
 

slickdude

Member
Joined
Dec 10, 2011
Messages
276
Hi guys, I have a china girl moped and was considering making my wife's bike into an Ebike. I can find all types of controllers and motors but the batteries are twice the cost of the hardware. So what batteries are you guys running and what are my options? Thanks in advance.
My guess might be to wait into 2019 if possible. "Solid State" Graphene batteries are on the way. They recharge super fast, last a long time and give many more amp hours than today's LIFEP04 batts do. Seems these are not the only ones, their are metal Ion batts too so a number of competing new technologies are coming. I would skip the 21700 Testla batts for now and I wouldn't invest in the 1869 batts as these are pretty outdated.

I think the new Schwinn ebikes have the Graphene batts from Samsung in them so it is happening already.
 
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