As we transition into mid-drive systems, imagine this scenario. A rider with a hub motor driven electric bike approaches a very steep hill, stops completely and then uses a twist throttle to power forward. The motor is likely going to struggle because it is designed for relatively flat surfaces and provides “peakey” output as mentioned before. So the motor groans and slowly pushes the rider forward. Without pedaling along, most hub motor designs just cannot carry an average sized passenger up a steep incline from rest. This is where we get into the benefits of a mid-drive system.
So I’m going to first use a wider (285 mm to be exact) but shorter piece of shrink wrap to go around the long direction of the pack. That will seal the ends first, and then I can go back with my long and skinny piece of heat shrink to do the length of the pack.
E-bike usage worldwide has experienced rapid growth since 1998. In 2016 there were 210 million electric bikes worldwide used daily. It is estimated that there were roughly 120 million e-bikes in China in early 2010, and sales are expanding rapidly in India, the United States of America, Germany, the Netherlands, and Switzerland. A total of 700,000 e-bikes were sold in Europe in 2010, up from 200,000 in 2007 and 500,000 units in 2009.
When it comes to layout, there are two ways to assemble cells in straight packs (rectangular packs like I am building). I don’t know if there are industry terms for this, but I call the two methods “offset packing” and “linear packing”.
One of the first Gravel Grinder style electric bikes to make it to America! Made with premium components, high performance lights and a purpose built frame in three sizes. Capable of high speed 28 mph performance, the Bosch centerdrive motor measures bike speed, pedal……
Description: Use this 1000W 48V 26″ electric bike conversion kit to transform your bike and eliminate the need for purchasing a brand-new electric scooter. The motorized wheel, electric controller, …
The first pedal-assisted bicycles appeared in India in 1993. In 2008, the sales of e-bike sales exceeded moped sales. In recent years, 2-passenger and even 3-passenger (two adults and a child) e-bikes were introduced in India.
I’m a little worried that your batteries aren’t what you think they are. If they really are AA sized, which is rare in the lithium battery world, then they are not 3,000 mAh. Next, 10 cells in series is going to give you 36V, which is twice what your 18V drill is rated for. 5 cells in series and 2 in parallel would be a better method. I usually recommend a BMS but you can skip it if you have another way of diligently monitoring your cell voltages and then charging using an RC style balance charger like an iMaxB6 charger through an JST-XH connector.
Yes, that’d work, but I’d get an additional 7s battery so you have 20s total. Also, you should know that the older your original 48V battery is, the more time it will take your new 72V combined battery to balance, as the first 13 cells will likely have less capacity in comparison to the newer cells. I made a video recently showing how to do this upgrade that you’re talking about: https://www.youtube.com/watch?v=9KHo-T74IWA
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?
Sorry Benoit, but that won’t work. The BMS will expect the full 10 cells and when it sees that cells are missing, it will assume they are at 0V and not provide any power. You need a 7s BMS, which are pretty commong. 8s will be harder to find for li-ion, but you could do 8s with LiFePO4 and those 8s BMS’s are common.
Now that we’ve got all http://electricbikebatterycharger.com pesky planning out of the way, let’s get started on the actual battery. Our work space is clear, all our tools are on hand, we’ve got our safety equipment on and we’re ready to go. We’ll begin by preparing our individual 18650 battery cells.