Offset packing results in a shorter pack because the parallel groups are offset by half a cell, taking up part of the space between the cells of the previous parallel group. However, this results in a somewhat wider pack as the offset parallel groups extend to each side by a quarter of a cell more than they would have in linear packing. Offset packing is handy for times where you need to fit the pack into a shorter area (such as the frame triangle) and don’t care about the width penalty.
Most of the problems occur when charging an ebike because they are unsupervised and that is when a LiPo fire can burn down a house etc. Use common sense on where you are going to charge your bike or battery pack, so that if it does burst into flames it does not take your house with you. I have a big steel barbecue grill set up in my entryway which I charge my battery packs in as nice safeguard. This involved taking the battery pack out of the bike after each ride but I am OK with that:
Sir, Your article does not describe the different methods to activate and control the motors. Do you have a separate article that deals with that? I am hearing about throttle, cadence and torque sensors, and others. Where can one learn about that aspect of the bikes? Thank you.
Gotcha. Can you recommend a manufacturer that sells a two wire version? Maybe I can look around their products and see if they sell any 7S cells, rather than sifting through all the manufacturers on Alibaba. Searches for “2 wire MBS” didn’t yield much. Thanks again for your help with this!
Hi Micah, thank you for your advice. I am not going to touch that battery. I know this may be a lot to ask, but would you build me a battery for my velomini 1 ? It doesn’t have to be the one that fits in the frame, I could put it in a bag and hang it on the handlebars or something. If more convenient you can email me directly at dlimjr at yahoo. My sincere thanks and may you and your family have a happy holiday.. Don, San Francisco
1x 48V 1000W Motor. 1x 48V Controller. The kit includes a motorized wheel, an electric controller, the speed throttle, the power breaks, and a wire harness. 1x 26″ Front Wheel. 1x Rack. Braking causes…
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.
Yes, it’s technically possible, but sometimes it is easier said than done. If the cells are on the edge of your battery, it’s much easier to cut them out (by the nickel, not by cutting the actual cell!) and replace them. If they are sandwiched in the middle of your pack then you’ll have to do a lot more pack surgery to get in and replace them. But yes, it’s possible to just remove them and replace them with new, good cells of the same capacity.
A premium folding electric bike with Bosch drive system and leading warranty, sturdy and quiet with plenty of adjustability (seat post height and stem angle), smart accessories help you carry gear and stay dry without noise. The folding joints are thick and sturdy but don’t have sharp edges, both latches have……
Warning: if a cheap electric bike is advertised and the advert does not state what kind of battery it has, you can pretty much be certain that it has a lead-acid battery. It might be cheap, but it’s not a bargain. This battery type might be good enough if you want the bike as a mere toy, to be taken out and played with occasionally in your immediate neighborhood – but if not, it would be better to avoid these batteries altogether.
Ideally, I would buy a battery with the same type of connection and just carry the spare one unconnected and swap them over but I don’t seem to be able to find the type of battery case for sale anywhere. It’s a quick release bottle type battery that has two sprung terminals about half inch in diameter that contact with two large terminals on what I think must be the motor controller integrated into the bottom of the bottle mounting bracket.
The Dapu geared hub motor is made by a Japanese company in Shanghai, China. The Dapu motor is a geared hub motor. This motor type is distinct from a direct drive motor like Bionx, and has a variety of benefits stemming from its design that can be appreciated in its https://en.wikipedia.org/wiki/Electric_bicycle ride feel and performance. Geared hub motors work by transmitting power from a high RPM motor to the slower RPM wheel through a system of planetary gears. Because of the physics of electric motors, this “gearing” allows for higher torque and efficiency from the motor. Thus, the ride feel of a BH Neo bike is extremely sporty with consistent torque, even up
Fat tires aren’t just for sand and snow, cruise your city with the @igoelectric Folding Fat! #foldingfatbike #fatbike #fattiesfitfine #fatbikelife #foldingbike #ebike #electricbike #electricbikes 02.02.2018 – 19:56
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Why do we alternate sides of the pack during the welding process? We do it because in this way we connect the positive terminal of each parallel group to the negative terminal of the next group in line. That’s how series connections work: always positive to negative to positive to negative, alternating between the two.
Alibaba.com offers 176,508 electric bike battery products. About 29% of these are electric bicycle, 22% are rechargeable batteries, and 8% are electric bicycle battery. A wide variety of electric bike battery options are available to you, such as 36v, 24v, and 48v. You can also choose from lithium battery, high voltage, and lead acid battery. As well as from 10 – 20ah, 21 – 30ah, and > 40ah. And whether electric bike battery is paid samples, or free samples. There are 176,462 electric bike battery suppliers, mainly located in Asia. The top supplying countries are China (Mainland), Taiwan, and Vietnam, which supply 99%, 1%, and 1% of electric bike battery respectively. Electric bike battery products are most popular in North America, Western Europe, and Northern Europe. You can ensure product safety by selecting from certified suppliers, including 39,033 with ISO9001, 14,496 with Other, and 6,372 with ISO/TS16949 certification.
Once you’ve got 2-3 welds on the top of each cell, turn the 3 cells over and do the same thing to the bottom of the 3 cells with a new piece of nickel. Once you’ve completed the bottom welds you’ll have one complete parallel group, ready to go. This is technically a 1S3P battery already (1 cell in series, 3 cells in parallel). That means I’ve just created a 3.6V 8.7Ah battery. Only nine more of these and I’ll have enough to complete my entire pack.
Note: At multiple points along this article I have inserted videos that I made demonstrating the steps involved in building a battery. The battery used in the videos is the same voltage but slightly larger capacity. The same techniques all still apply. If you don’t understand something in the text, try watching it in the video.
I have built a few 13s lithium batteries in the past year following your instructions. Thanks. I have taken one of the batteries apart to check its condition as it is the middle of winter here in Winnipeg, Canada. Two parallel sets were out of balance with the rest of the pack. I was wondering if there is a way to use my imax b6 balance chargers to rewire the battery and keep each parallel pack in balance for sure! This way I will bypass the bms. Does this make sense?
Hmm… All of these are going to be impacted by rust if he’s near the salt water a lot. I’d probably go with the mid-drive BBS02 just for torque and balance given the difficult soft terrain. To answer your question about torque on geared vs. direct drive, I find that geared is more powerful and lighter weight but also louder and sometimes less reliable long term. If you want to go the cheap route I’d go with the geared rear hub (no front hub motor… just more to break). You could consider a front hub only to make it two wheel drive by him pedaling to move the rear wheel and the front wheel using electric but then it might spin out more. The front wheel would probably be best protected from the sand and water and the easiest to install… but again, less traction there as most body weight goes towards the rear wheel, especially when accelerating. I’d love to see pictures of the end result and hear your thoughts in the forum, maybe others could chime in on this subject there as well.
What are some inexpensive controllers that can send more power to the GNG mid drive? I saw some guy on YouTube claiming that he got a $30 controller that handles 35-45 amps. I don’t see any $30 controllers on eBay.
If you want to learn more in-depth about building your own lithium battery, you’ll want to check out my book “DIY Lithium Batteries: How To Build Your Own Battery Packs” which is an Amazon #1 Bestseller in multiple categories!
I then took my second sense wire (or your third sense wire if you have one more sense wires than parallel groups) and soldered it to the positive terminal of the second parallel group. Again, note that I’m soldering this wire to the nickel in between cells to avoid heating any cell directly.
As the weather begins to drop and the snow starts to fall, it is increasingly important to know how to properly care for your electric bike and its Lithium-ion battery. It may be possible for some people to ride their bikes during the winter months, while others must pack them away until the warmer weather returns. Whether you plan to ride in the cold and snow or if you decide to…
As an aside, the 50A-800A you’re talking about is during the output, and that’s at a very low voltage, which is the reason for the high current draw. But that power equals a much lower current on the input end where it draws from the wall outlet.
You’ll also want to test out the battery with a fairly light load in the beginning. Try to go for an easy ride on the first few charges, or even better, use a discharger if you have one. I built a custom discharger out of halogen light bulbs. It allows me to fully discharge my batteries at different power levels and measure the output. This specific battery gave 8.54 Ah on its first discharge cycle at a discharge rate of 0.5c, or about 4.4 A. That result is actually pretty good, and equates to an individual average cell capacity of about 2.85 Ah, or 98% of the rated capacity.
if you carry the right tools its actually not that hard. doing it on the side of the road usually takes me about 20 minutes. it can vary from set up to set up, as you have to take apart the assembly off the bike and then pull out the tube, which can be difficult on some tires that have tough rubber treads. i would also suggest that someone care a head mount flashlight (my local dollar store sells them) as it will allow you to change them when its dark out.
Modern E-Tube networking: the wireless Di2 EW-WU111 by Shimano. The EW-WU111 can be connected with your smart phone, tablet or PC and once connected it shows the gear and the current battery status. The connection between the two devices is made over the new E-Tube App via Bluetooth®.
We’ve learned some users love connectivity to our Electron app, while others will prefer to ride without it. That’s why we’ve engineered an app that lets you choose whether or not to use its features like distance and speed tracking, battery life readouts, assist levels, and ride mapping. If those aren’t for you, just calibrate your wheel once with our app, and then enjoy the wheel free from any device.
^ a b c Chi-Jen Yang (2010). “Launching strategy for electric vehicles: Lessons from China and Taiwan” (PDF). Technological Forecasting and Social Change (77): 831–834. Archived from the original (PDF) on 2010-03-31.
To reach our intended voltage of 36V, we have to connect a number of 18650 cells in series. Lithium-ion battery cells are nominally rated at 3.6 or 3.7V, meaning to reach 36V nominal, we’ll need 10 cells in series. The industry abbreviation for series is ‘s’, so this pack will be known as a “10S pack” or 10 cells in series for a final pack voltage of 36V.