Comments on: EBIKE 72v – Battery pack built from Dell laptop batteries

By: MaxSachs

MaxSachs — Wed, 14 Sep 2011 00:30:33 +0000

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?

By: skeetab5780

skeetab5780 — Wed, 14 Sep 2011 00:20:45 +0000

@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

By: backlash170

backlash170 — Wed, 14 Sep 2011 00:05:30 +0000

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

By: skeetab5780

skeetab5780 — Tue, 13 Sep 2011 23:31:44 +0000

@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