Saving another Giant Lafree

giantfan

Just Joined
Sep 22, 2013
3
0
israel
I have a wonderful LaFree, the original NiMh battery no longer takes charge after 11 years of use; and am considering my options; which are somewhat complicated by the fact that the bike is in Israel where I vacation two or three times a year and a battery this big cannot apparently be taken in an aircraft over from the UK.

Presently I am considering ordering from China a 24v 20AH Lithium battery so as to carry out a fairly radical modification, and hopefully end up with a more powerful and enduring power pack. It wont fit where was the Panasonic battery but could go over the rear wheel on a rack or mounted just below the seat.

Don't know if my plan will work. Anyone tried? Am happy to provide progress photos if of interest to anyone. It could be rather fun, especially if the modification actually works!

I havent decided whether to remove the guts of the NiMH battery and use the contacts at the foot to connect or to just solder onto the contacts down there. Any advice?? Hope this doesnt turn out to be a scrapheap challenge!
 

flecc

Member
Oct 25, 2006
53,528
30,828
Yes, lithium batteries have been used and work ok on the Lafree, the slightly higher voltage (25.9 volts nominal) not affecting them. You must get the correct charger for the lithium battery of course. THe existing Lafree contacts could be used, but they aren't particularly good, so suitable inline connectors like the Anderson Powerpoles would be a good substitute.
 

giantfan

Just Joined
Sep 22, 2013
3
0
israel
saving another lafree twist

Yes, lithium batteries have been used and work ok on the Lafree, the slightly higher voltage (25.9 volts nominal) not affecting them. You must get the correct charger for the lithium battery of course. THe existing Lafree contacts could be used, but they aren't particularly good, so suitable inline connectors like the Anderson Powerpoles would be a good substitute.
Thanks very much indeed. Shortly before the battery died I did notice the motor had got a bit notchy "clanging sound" on top gear. Is that a simple fix or indicative of a major issue??
 

flecc

Member
Oct 25, 2006
53,528
30,828
I can't say without hearing it or experiencing the effect, but the internal gear system is very robust so unlikely to be a problem. Very occasionally a motor bearing can fail and start producing noise but not any particular notchy feel. Most problems of this nature are associated with the bike's chain drive in the motor sprocket and idler area.
 

giantfan

Just Joined
Sep 22, 2013
3
0
israel
many thanks indeed. new 24v 20Ah frog style battery is now on the way. Might I ask you precisely where you would suggest connecting in the new battery to the existing rig?

Incidentally, despite attracting high import tariffs, (cars are subject to 100% import tax) electric bikes are phenomenally popular over here, I've noticed the ones available generally seem to have comparatively small wheels. The same models are for sale in the UK but under different brand names. My giant came over in a removal and before the battery packed up was an item that attracted a lot of interest!
 
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flecc

Member
Oct 25, 2006
53,528
30,828
I'd connect extension cables from those under the present battery platform (usually red and white on these), running them up to the battery mounting platform and using connectors there. Most e-bikes have an isolation switch in the positive path, but the Lafree always relied on the handlebar on/off alone.

Pedelecs member "Grandad" added a dual battery arrangement to his Lafree and his website describing that may have the odd details to interest you. Here's the link.
 

flapajack

Pedelecer
Aug 4, 2013
114
33
Hi giant fan

How goes your lithium battery conversion?
How does the bike behave/respond since and what was the experience with the conversion? Any tips to share and most importantly any pictures?