Ravi,
Great link and excellent observations. Addressing the battery chemistry question, I'd say pretty much all of the stuff coming from major brands is working well. You're right. There are thousands of combinations. Most of the Ebikes we've taken on are new enough that they shouldn't start degrading for a few more years (more than enough time to make it into SSD gen stuff). We've seen some problems with a couple of new battery types, but I'd attribute it to a factory issues instead of the actual chemistry. These are almost always easily warrantied. Court does a good job of pointing out who has good service.
Otherwise, I'd use caution in buying second-hand Ebikes with proprietary or unique battery casing. For example, my wife picked up an old Currie Enlightened series last year and we immediately replaced the battery with a new one from Currie. Unfortunately, the new battery was probably sitting in a warehouse and now her range is already close to nothing. Her only option is to repack with new chemistry and that can be costly. Fortunately, many of the Currie models still use the same casing and can easily be updated. (I'd also say that Currie's batteries became MUCH better after Accel purchased them.)
Buying batteries direct from China is going to be hit or miss. We do a lot a repairs on these, and it's difficult to say if the wholesalers are trying different companies or the quality control is simply poor. Unfortunately, QC in China is always going to be a problem, even for major brands (as we've seen this year). Again, the Ebike companies are quick to warranty any problems, but Chinese sellers usually offer short warranties and are difficult to follow up with. Do your homework before you buy.
In terms of getting the best range, well, that's a big question.
First understand that every Ebike is going to have a huge variation in range depending on the rider and conditions. SERIOUSLY. We're talking about 10 vs. 50 miles. Rider weight is a giant consideration. Hilly terrain (mountain biking) can seriously sap a battery. That said, large riders in mountainous terrain will still get great range provided they are doing their share of the work.
For example, yesterday I did some serious mountain biking with a 140 lb. rider and a 230 lb. rider. Both were on
BH NEO MTB's and after an hour of hard riding the larger guy had only used 10-15% more battery because he was the more experienced of the two. Amazingly, I've seen a 300+lb. guy do the exact same trail on the exact same bike and use the same amount of battery! All he did differently was gear down and spin it out.
The important thing in extending range is balance your work with the motor's. With a PAS/cadence sensor, it's about finding a speed which your pedaling is starting to match or overtake the motor. This can make your range unreal with a bike like an
e-Joe Angun which has a 16 amp/hr battery and a 12 mph level one PAS. With a torque sensor, maintaining a good cadence with proper gearing (as you should with any bike) is the key to good range. As Court frequently points out, this is also good for the freewheel.
Obviously, throttle bikes are going to require more attention and finesse. I find that just using the throttle for acceleration and then cruising really extends range.
Also, note that some of the smoother torque sensors are better for range as well (
Bionx,
Stromer,
Eflow). You'll just get more of a workout!
Sorry for the giant response.
-Chandlee
