I have had a Bionx 350PL since June 2008. I now have about 5000 miles on the system and it has performed fairly flawlessly. I ride it year round, pretty much every day and in all kinds of weather. I have found the system very pleasurable to use. The only operational problem has been a very occasional hiccup where the control system locks up - this happens about once a month and the fix is to disconnect and reconnect the controller. it is still riding perfectly.
BUT - the battery is now down to below 75% capacity. I have remeasured this very carefully, doing multiple rides on a standard course I use. All at pretty much the same temperature and wind conditions. Unfortunately, I have no energy measurement system that can accurately measure how many aHr I have used. But the change is extremely noticeable.
I contacted the distributor that sold me the kit before my 1-year battery warranty was up in late June. They suggested I reset the battery monitor ( fully charge the battery, let it sit a while, then put in a code that sets that level to "full" on the indicator) and also completely drain the battery several times.
I did this and noticed no changes. By now it is August as it took me that long to perform the cycles and then retest the range several times.
They then contacted Bionx who said that my mileage in one year ( about 4000 miles) was extreme and maybe that might be the problem. I think they misunderstood my mileage, as 4000 miles per year is nothing. I use to put a good bit more on my commuter bike back before I had an assist kit. We had some back and forth and no resolution.
I then contacted Bionx directly and they immediately responded, saying someone would get back to me but that time and storage can affect battery life. In my case, the battery was only a year from purchase when I first noticed the drop, and I baby the battery - only charge it when it has cooled down, keep it in a heated garage, etc. I also never completely drain the battery except when it was suggested as a way of re balancing the cells.
They've never got back to me and I'm about to give up.
But at this point, as much as I have enjoyed the Bionx system, I have to recommend against anyone purchasing it. Bionx rates their battery for about 400 cycles. Now most rechargeable battery manufactures rate a battery life as the number of cycles until its capacity has fallen to 80%. In my case, the way I use the bike ( always at level 2, no thottle) I get about 35 miles per cycle. So 400 cycles, at 80% of this range, is about 11,200 miles. I was a little over a third this range when it fell to 75% capacity. (Greenspeed and some other distributors advertise 500 or even 600 cycles).
When I made the decision to purchase the bike, I knew the $1000 battery replacement cost was extraordinarily high for a 36V 9.6 ahr lithium battery, but I figured it would be worth it for a nicely performing system over 12,000 miles.
But with my system lasting only a third of this life, I now feel this is not a very good value at all and would not recommend this system to others.