Hello Micah: Thanks for this most interesting and useful article! I want to build a battery in a 39mm x 520mm seatpost for fueling a 250W motor that normally uses a 7.2 Ah – 25 V bottle-shaped battery. The new seatpost battery should only have an autonomy of 7 miles of steep hills (40%) between each daily charge. What are your recommendations? Happy day! Fred
I’ve been building a 13s6p Li-ion battery based on your article, and everything went swimmingly (except underestimating the amount of nickel I’d need) until I started hooking up the BMS. I was in the middle of hooking up the sense lines, and the BMS smoked. Opening it up, it looks like a few of the caps that couple adjacent nodes burned. Have you seen this before? Any thoughts on what I may have done wrong, or does this just happen sometimes when a cap’s voltage tolerance is outside spec?
3. Yes, 18650’s with capacity ratings of 6000 or 8000 mAh are fake. The technology simply doesn’t exist to put that much energy in a cell that size on an economical level. In a few years we might be there, but not right now. Currently, the biggest cells are in the high 3,000 mAh range for 18650’s. 26650’s are larger cells and so those can have higher capacities, but there are many fewer options and variety of 26650 cells, so 18650’s are the common cells used in ebike packs.
The only two ebike companies that sell LiPo to the public are Optibike and Pi-cycles, and both contain the battery in a strong metal box which makes up of the frame. The companies fire tested these enclosures and are confident that their frame are effective and safe vessels for LiPo storage.
Any electric bicycle could use any of these sensor types (or multiple sensors like throttle and cadence sensing assist) but Class 1 only allows for assist while Class 2 allows for throttle and assist. So it’s not a matter of linking motors with sensors and input types (even though some motors only work with specific sensors) it’s a matter of how the manufacturer built the bike and which control systems they chose. All Bosch driven bikes use a combination of cadence, wheel motor and torque… Some BionX use a trigger throttle and a torque sensor. Hope this helps
This article first appeared in Electric Bike Report in June of 2013. Since then, we’ve made some changes to our motor selection – our Direct-Drive motors are now all High-Torque 6×9 wound, so they run slower (approximately 15mph at 36v or 20mph at 48v), and our Geared Motors have been replaced by a 500w version, (approximately 20mph at 36v or 28mph at 48v). The Direct-Drive is now our Heavy-Duty motor and the…
Torque sensors and power controls were developed in the late 1990s. For example, Takada Yutky of Japan filed a patent in 1997 for such a device. In 1992 Vector Services Limited offered and sold an e-bike dubbed Zike. The bicycle included NiCd batteries that were built into a frame member and included an 850 g permanent-magnet motor. Despite the Zike, in 1992 hardly any commercial e-bikes were available.
To develop a new hub motor would cost over $500,000 in tooling costs for a factory in China. Thats why even though there are many hub motors around for E-bikes, most are the same types or clones of existing types. Here is a list of known acceptable qualty hub motors available as of March 2012.
The motor kit is available with either a 360 watt or 500 watt motor. It comes complete with a universal mounting bracket and all parts necessary to convert most standard or http://bestelectricbikebattery.com bikes to e-bikes with just a few hours effort. The links above will provide all the information you need to get a Cyclone Motor Kit working on your e-bike project.
The battery maximum power = volts x amps, so if this 36V battery can deliver 30A continuous, that means it can deliver a maximum of 1,080 watts, though I would run it conservatively at a lower power level than that in most applications.
This is the old technology for e-bikes that is heavy as bricks and does not have longevity. Lead acid will double the weight of your electric bike. Unless you have to because of money restraints, we advise to steer way clear of lead acid batteries. Your bike will have a completely different feel and range if you spend the money on one of the new lithium technologies.
Battery chargers for electric bike batteries need to be specific for that voltage and type of battery. Lead batteries need a charger that trickle charges when finished, while lithium battery chargers do not trickle charge. E-Bikekit batteries are sold with the correct charger that matches the voltage and type for that battery.
Hi, Until reading your article, I knew nothing at all about how hub motors actually worked in practice. I have a serious agenda by contacting you. My wife and I purchased an Italian make of mobility scooter that uses a hub motor on the front wheel of a tricycle type, fold up machine. It is a very clever design, but after using the scooter In Puerto del Carmen that, although scooter friendly, has some steep hills, we have encountered some serious drawbacks. After using the scooter for about two weeks total, my wife had the scare of her life when driving down a slope, she released the throttle expecting the scooter to brake but nothing happened, resulting in her shooting across a busy street, thankfully devoid of traffic at the time. Could this be that some sort of internal friction brake is wearing out due to extreme use in hilly streets or are the electronics that should control braking failing? I tried the scooter myself and found that when travelling down hill, unless a really slow speed is maintained, should you speed up, it appears that the mass (me, 93Kg)) and inertia (gravity/speed) overcome the braking system and the machine carries on regardless. I would be interested to hear you opinion. I have issued a “customers report” both to the retailers and the manufacturer’s, going into greater detail on my “field testing” but I have yet to hear back from the manufacturers. I feel this is a serious issue as it could affect other customers in similar circumstances. Brutally honest feedback should be exactly that, otherwise it is useless.
Depending on local laws, many e-bikes (e.g., pedelecs) are legally classified as bicycles rather than mopeds or motorcycles, so they are not subject to the more stringent laws regarding their certification and operation, unlike the more powerful two-wheelers which are often classed as electric motorcycles. E-bikes can also be defined separately and treated as a specific vehicle type in many areas of legal jurisdiction.