EBIKE 72v - Battery pack built from Dell laptop batteries

I purchased a lot of 12 laptop batteries for a very good price. they are 14.8v 5.4ah packs 12 cells of 18650 lithium inside. im taking them all apart, and building a 72volt 10.8ah pack for my Ebike

Category:

Music

Tags:

• electric bike
• EBIKE
• lithium batteries
• laptop batteries
• 18650 cell
• battery pack build
• 72v
• 72 volts
• 36v
• 36 volts

[FullFledged2010]

So if i take 36V 16ah pack+ 24V 16ah pack would that make a 60v 16ah pack?

[skeetab5780]

@FullFledged2010 If they are wired in series yes.

[backlash170]

how do you know what to charge them at? i want to build a lithium 48.1V 4.0ah pack out of 3.7V 4.0ah single cell batteries but im not sure how to charge it, or what kind of charger to look for

[skeetab5780]

@backlash170 they have li-ion smart chargers that charge 10cell (10x 3.7v cell full charge 41v) or you step it up to whatever voltage you want 15 cell will give you 61.5v fully charged. then just get a 15cell charger. It is always recommended to use a battery management system when using most all batteries

[MaxSachs]

Those look like Sony Konion cells that they use in Makita 18.5V powertool batteries, I'm not sure but the "GR" designation may mean a lower discharge rate than the 18650V version. The 18650V versions are rated at 10C discharge and are quite suitable for ebikes but it just doesn't make sense to put a 10C cell into a laptop....overkill. Have you tested or researched the discharge rate of these 18650GR's?

[skeetab5780]

@MaxSachs i have not tested these cells yet, but yes you are correct these cells have a higher density and a lower discharge rate compared to a V or VT sony cell. im not expecting more than 1C to 2C as im only needing the pack to draw 30Amps. i think they're 1800mah some people say up to 2200mah depending on discharge. once the pack is built i will post an update! thanks for watching

[pandorachild]

cost?

[szaki]

Wouldn't it be cheaper just buying Lipo batterie cells new?

[skeetab5780]

the pack configurations are 10s6p so there will be a balance wire on each positive lead of the 6 cell parallel groups.

[lkgboater71]

Neat idea.  Do you plan on balancing each cell when charging or each 3-cell group?