Giant batteries do come back to life!

alanterrill

Pedelecer
Dec 3, 2006
66
0
About three years ago, we noticed that my wife's MiMh battery on her Giant Lafree Twist seemed to be losing capacity. When we went out together, hers would fail at about 12 miles whereas mine would go for 15. Having read about the battery packs available from Powercycle which were available for £99 at the time, I bought one and fitted the cells into the Giant pack. Surprisingly there was no percivable difference in the mileage from the new battery. What is probably more pertinent is the fact that my wife is 13kg heavier than me, and when we swapped batteries, her bike still did less miles than mine!
However -we continued to use the new one with the old cell pack abandoned in the garage.
Also during this time I acquired an old spare battery from Flecc with the intention of using it as an emergency spare on longer journeys, recelling it eventually when it dies. Initially this one gave me about five or six miles at most.
After about 15 months the recelled pack started to give noticeably less power. By this time, I'd acquired a new Giant lafree and so we had a spare battery, and my wife used my spare one instead and the recelled one sat idle for some months. As the powercycle pack hadn't proved great and the price had gone up in the meantime, the Flecc battery also stood idle for many months.
Eventually one winter evening I decided to get all the old packs out of hibernation and I checked the voltage of the packs (the two complete ones plus the set without a case). The two Giants were giving around 21V if I remember correctly, but the Powercycle pack had dropped to about 15V. I checked each individual cell, and then found that around 4 of the Powercycle cells had dived to around 0.5V . So I replaced the original Giant cells into the casing they had originally come out of, and then tried to charge both this and the Flecc packs. Initially they started to charge but gave up at two or three lights on. I discharged them and tried again, and over about four recharges they both came up to full charge.
I then took them out on the road -to my surprise the Flecc now now gave me 11 miles (and I'm talking about hilly country) and the original Giant gave around 14.
So now my wife and I put one of these in our rack bags whenever we go on journeys of 12 miles or longer and they continue to give good service.

Just thought you'd like to know in case anyone has an old battery lurking about which they've given up on.

Alan
 

flecc

Member
Oct 25, 2006
52,764
30,349
Thanks for the information Alan. I know that the best NiMh cells can be revived by re-conditioning cycles even when quite old, so it's good to have this confirmation of the Panasonic cell quality.

I'm afraid the Powacycle cells haven't been as good for most users. The 8.5 Ah cells they use are still those commonly available now, and I've had confirmation from another e-bike manufacturer of their poor specification, which includes an inadequate maximum discharge rate, meaning they are stressed under fairly normal working conditions, leading to shorter life.

Still, I suppose at £99 for a complete battery we couldn't expect too much against the £250 Panasonic battery.
.
 

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