Recelling my Giant Lafree battery

[neil mcfarlane]

re-celling la free

Thanks Jac and Flecc for your replies.

For £80 each including postage, these ones from China seem ideal:

electric bike Nimh rechargeable battery pack - Detailed info for electric bike Nimh rechargeable battery pack,electric bike battery,electric bike Nimh rechargeable battery pack, on Alibaba.com

The ones illustrated are 8,500 mAh, but it says they are available from 6,000 mAh to 13,000 mAh. Is it just a case of the higher mAh the better?

Anybody want to take one off my hands? Is there anything I should be wary of? I have experience of many areas of life but importing battery packs from China is not one of them. Any comments appreciated.

 

[neil mcfarlane]

re-celling la free

Oh and this info was included in the email from the company quoting me a price:

**********
24V 8.5Ah Nimh e-bike battery pack at USD 125 CIF United Kingdom
Discharge: 12A ( Max 24A)
Size: 24cm*10cm*6.5cm
**********

No idea what "Discharge: 12A ( Max 24A)" means.

 

[flecc]

If correct that discharge rate will be just about sufficient, the Lafree can peak demand around 16 amps, but since the peak rating is 24 amps it should cope.

Ignore the 13 Ah version, that is most likely to use F cells which are the same diameter as the usual D cells but half as long again so won't fit into your case. The greater the Ah (Ampere hour), the longer the range, but increasing the capacity in the same cell size can mean a shorter life through more stresses. Safer to stick to the 8.5 Ah as these batteries are an unknown quantity.
.

 

[Jokmath]

Chinese batteries for Lafree Lite

I have a Giant lafree lite with a defunct battery so might be interested in getting one from you if the forum reckons they could work - seems a good price and haven't been able to get any answer from the Component shop which seems to be the other place to talk to. Not sure I am competent to fit it but no doubt someone can. Let me know if you decide to go with this.

Charles Mathieson

 

[neil mcfarlane]

re-celling la free

Hi Jokmath

Will do.

I'm not looking for forum members to personally guarantee these batteries of course, but if the product description fits the la free's specs, I'm willing to take my chances. Flecc's "just about sufficient" has put me off somewhat. Does that mean the specs are not very good and they are borderline batteries? Would the £125 Component Shop packs be better batteries (forgetting about price for one moment)?

I was also interested to see almost identical looking batteries on the Bateryspace site here as the ones on the Shanghai Wanhong website (the top photo here: BatterySpace.com/AA Portable Power Corp. Tel: 510-525-2328 - 24 V Battery Pack Series

Makes me wonder if Batteryspace don't just get them from the Wanhong and wrap them in a different plastic. I realise those batteries in the photos are different sizes, but the clips, the colour scheme, the label position are all so similar.

Thanks again for your comments.

 

[flecc]

Flecc's "just about sufficient" has put me off somewhat. Does that mean the specs are not very good and they are borderline batteries? Would the £125 Component Shop packs be better batteries (forgetting about price for one moment)?

Makes me wonder if Batteryspace don't just get them from the Wanhong and wrap them in a different plastic. I realise those batteries in the photos are different sizes, but the clips, the colour scheme, the label position are all so similar.

I'm being cautious since I know from one major e-bike maker that the only economically priced NiMh D cells he could get were 8.5 Ah ones that he'd measure as only realistically having a 5 Ah continuous discharge rate. That was a little while ago, but given that prices have been increasing it seems unlikely that the top end types would be much cheaper. If the specification of that Chinese pack is correct, I would have been happy to use it in my Lafree since the maximum current need of 16 Ah is only used when the rider input to the torque sensor is very high, something that doesn't happen continuously. The 24 Ah peak capability if correct can easily cope with that intermittently.

As for Batteryspace, some have used their 10 Ah packs previously and they've proved to perform well, but since that was also some while ago, things could have changed. A lot of the difference between a good and a bad NiMh battery pack is in the cell matching, since it's essential for NiMh cells in series to be well matched. That's because NiMh have no electronic charge management in the way lithium batteries have with their integral BMS circuits. It follows that two pack constructors can produce different results using exactly the same cell type.

At cut price levels and especially buying direct from China, there are no guarantees, it's necessary to take a risk and hope it works out.
.

 

[neil mcfarlane]

re-celling la free

Thanks again Flecc. I think i'll go for it.

I posted in the classified section to see if anyone else is interested.

 

[Grizzly Bear]

Hi
there's been good reports about the Maplins hybrid cells, now on offer for £6.99 for two. I bought some to re-cell my wheel hub battery (I know Tony I'm a LIFEPO4 boy, but I really like the hub battery idea). Anyway it cost me £104 (delivered to my door) to re-cell the now 8Ah 36 volt battery, plus £10 for some nickel sheet for the links.

Griz