I've been doing some research on electric bikes, batteries and motors etc. Some good technical articles are out there so I thought I would share a few.
Lithium battery technology - some good safety info here.
http://www.electronics-lab.com/articles/Li_Ion_reconstruct/
Good general electric bike technical manual on this UK site.
http://www.atob.org.uk/questionselectric.htm
And this commercial site from the US has some good practical info.
http://us.itselectric.ca/Resources_s/19.htm
Enjoy
A little more research has uncovered an excellent Australian site, WA actually. The technical FAQ page is very informative.
Having travelled over 1000km on my electric bike since February I thought I'd put a few words down on my 'long term' testing. So far it has performed without any problems but it is still less than a year old. My typical daily rides range from a number of short trips up to 3km or a morning ride of up to 8km depending on the weather.
I usually recharge the 24v lithium battery once the trips accumulated to about 20km or so and the battery meter of 5 leds has never dropped below full up until fairly recently. It now seems to be dropping more quickly once I go over 20kms which indicates the battery capacity may be starting to reduce. I'll know a bit more soon as now that I have noticed the change I will watch it a bit more closely with a digital volt meter.
Speed during cycling trips varies from about 12kmh on hills to 30kmh on good smooth road or paths. I used the hand throttle a lot initially as I enjoyed the speed but lately I've been just riding with the automatic 'pedal assist' mode generally giving a speed of 20-25kmh on good road. All in all it has been a real pleasure to use and once the battery situation becomes clearer I'll post a bit more.
Today for the first time I had to pedal the last couple of km's home. After 22.84km from the last charge all the battery meter leds went out and no pedal assist was evident.
My fitness and leg strength were put to the test for the final couple of k's home and only then does one fully appreciate how much of a difference the motor makes. Looks like I'll charge it every day from now on. At around 1200km's travel they are starting to show signs of lost capacity which has started me looking for possible alternatives, depending on the price of replacement.
Not sure whether to continue with lithium in the long term despite their weight advantages. EV's and hybrid cars are being fitted with long life lithium but I'd say the low cost ebikes have an inferior spec. After about a years normal use I'd say these are going to be done.
Morbo
Member
there was a documentary about 2 guys in China trying to sell Australian products over there, like a Holden V8. Think they got an electric bicycle for about $800. Might be worthwile make holiday in China, get the bike, come back and still be cheaper than that segway ripoff? Or try alibaba.com?
Update.
rockabye said:
At around 1200km's travel they are starting to show signs of lost capacity which has started me looking for possible alternatives, depending on the price of replacement.Not sure whether to continue with lithium in the long term despite their weight advantages. EV's and hybrid cars are being fitted with long life lithium but I'd say the low cost ebikes have an inferior spec. After about a years normal use I'd say these are going to be done.
After 4yrs 9mths and around 6000km my original ebike lithium battery still gives me daily trips of 10 - 12kms.
Originally the 7 cell 29V 10Ah battery would deliver around a 40km range however as discussed in my earlier post it had dropped to less than half that after 12 months of use. But I decided to persist with it, not least because a replacement was around $400.
More importantly I discovered interesting characteristics, both in how I used the ebike and how the lithium battery 'recovers' when rested. Usage aspects mainly relate to the fact that most of my trips are less than 10km. So the actual range of the depleted battery still manages to fit with my daily routines.
The other important outcome was that as I often have a lot of short runs of 3 - 6 km the battery seems to get a new lease of life after even a 30min stop while I'm at the library or shops. I had previously thought only the lead acids had a 'recovery' effect but my experience with a number of ebikes so far seems to indicate the lithiums also can benefit from time out.
At this stage I will probably upgrade the ebike to 36V (10 cell) at the 5 year point as it is still in excellent condition. Finally I can say the vast majority of the battery recharges have been through a standalone solar system.
All up the ebike has been an excellent performer and after now travelling around 12500km with several different ebikes in that time I can only recommend them.
Latest ebike mag issue 9 now online.
Lots of testing of mid-mount motor models included.
http://www.electricbikemag.co.uk
Also ECyclist magazine also now available online
