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?
I need your input on a trike conversion. I’m disabled, and working on converting a trike I got on the cheap to electric powered. I’m unable to petal, and handcycles are sooo out of budget it isn’t funny. I have a Trailmail Joyrider Junior. (i’m rather short so it’s a good size for me. The way it’s designed I can do a chain drive, mid drive or a hub (since I’m really just working with the frame) Which would be better for a full assist situation? I do have some graded hills around me too. Which one would be best?
Now I’m sure you’re all jazzed about building your own battery pack. But just in case, I’m going to leave you with an awesome video featuring battery builder Damian Rene of Madrid, Spain building a very large, very professionally constructed 48V 42AH battery pack from 18650 cells. You can read about how he built this battery here. (Also, note in the video his good use of safety equipment!)
If any one battery cell varies significantly from the others, do NOT connect it to the other cells. Paralleling two or more cells of different voltages will cause an instantaneous and massive current flow in the direction of the lower voltage cell(s). This can damage the cells and even result in fire on rare occasions. Either individually charge or discharge the cell to match the others, or more likely, just don’t use it in your pack at all. The reason for the voltage difference could have something to do with an issue in the cell, and you don’t want a bad cell in your pack.
I am in my early 60s, weight 165#, and in fairly good shape but atlas do not have the stamina and leg strength I used to have even in my 50s. Aging sucks! I live in a hilly rural area and do most of my biking on paved and unpaved (70/30%) back roads for recreation and exercise. The latter includes gravel and hard packed dirt and the occasional deeply rutted farm road. I do not intend to do any serious mountain biking nor commute using this bike. The routes I take have several long and moderately steep grades which is good exercise but too exhausting to tackle these days on my non-powered carbon road bike. My priorities are the optimum combination of comfort (including relaxed geometry), quality/reliability, versatility, range, and ease of use.
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…
Hi Court. I am a bit of a newbie but learning fast. Thanks for your help and the reviews. I like the idea of geared hubs and torque and 500 W w/ 48 amp. But can I be more experience specific? I’m about 180 lbs and moving to San Fran. I love the flats of the marina, the Embarcadero, Chrissy Fields, the Presidio etc but I live on the hills of Pacific Heights, some quite daunting. I also love to just cruise along and look. i like step thrus. I like to sit up in comfort and I love comfortable seats. Can you taylor make a reccomendation for me as to bikes to look at? The Pedego City Commuter looked interesting but the seat wasn’t comfy. I want ease, assist and throttle, cruiser comfort as well as nibble and quick with good endurance. AND critical, I want ease on the steep hills of Pacific Heights. Thoughts? Help?
Hi Craig, here’s a full comparison of the Thron with the ST2. In addition to suspension, the Thron has a better weight distribution given the mid-motor. The ST2 has more fancy smart phone technology and self-updates from the cloud (not sure if that’s online in the US right now). Both are great bikes and the price point is very similar. I’d love to hear your thoughts if you end up with one of these 🙂
A123 is a brand name of lithium ion phosphate battery used in many EV even full car applications.. A123 cells are known to be of high quality and capable of having high-amp discharge rates with long life expectancy of over 1000 charges. They can provide large amounts of power and have been used in racing applications as well as electric car builds. Chrysler has chosen to use A123 cells in their electric cars.
This Saturday, Oct. 7, Tim Sway will showcase his “UpTriCycle” at the Greater Hartford Mini Maker Faire. Sway calls the UpTricycle an “off grid, electric, solar charging mobile maker space and carrier for upcycling makers.” He uses minimal tools and footprints in his creation for unlimited potential. On his YouTube page, Sway made a comparison video between a gas-powered trike and an electric trike. He purchased a gas-powered trike first,…
Hello Court! I have spent a good deal of time the past few months researching e-bikes. I read your introductory book and nearly every online review you have written over the last year or so. The closest e-bike shops to me are about a two hour drive and are limited in what brands and models they stock (mainly city style bikes). So before I venture out to test drive a few models, I am seeking your advice to narrow down the type of bike and drive train that makes the most sense for my application.
at an extremely high efficiency (up to around 80%), doing more with less wattage, and thus not heating up too quickly while giving plenty of torque. In fact, in our testing of the new drive we’ve found it to be on par with a mid-drive motor system in terms of giving consistent torque on extremely steep hills. Other benefits of the Xion drive include a sophisticated control panel, regenerative brake assist, a quick release rear hub, and one of the most smooth performing torque sensors on the market.
Over the years our lineup has grown, and as a result, the offering has become more complicated than it needs to be. Specifically, this year we introduced a 500w geared motor option to the lineup and that has created some redundancy. Before outlining changes, we would like to ensure everyone that we will be stocking enough inventory of previously sold parts for a long enough time to ensure all warranties…
Sorry if this has been asked already but there are a ton of comments to wade through. Ten individual 18650 cells in series at a nominal voltage of 3.6 Volts would give me 36 volts. Assuming they are 2500 mAh a piece, then if I put 4 of these 10 cell in series packs together in parallel I would have a 10 Amp Hour battery correct? The same applies if I were to wire a pack together with 10 “4p” cells together in series. I’m trying to determine what the benefit of 10s4p over I guess what would be “4s10p”.
My goal is to reduce commuting time by 20 mins each way, eliminate ferry costs, keep exercising and enjoy the open air, but reduce being worn out by 1000km per month, reduce the payback period and keep replacement (battery/motor/other) costs low.
A lithium battery is the heart of any electric bicycle. Your motor is useless without all of that energy stored in your battery. Unfortunately though, a good ebike battery is often the hardest part to come by – and the most expensive. With a limited number of electric bicycle battery suppliers and a myriad of different factors including size, weight, capacity, voltage, and discharge rates, finding the exact battery you are looking for can be challenging and lead to unwanted compromises.
Also, since the negative electrode is the entire bottom and sides of the cell (formed by a metal cylinder) these cells can take some bouncing around. Be aware if you scratch the plastic wrap on the cylinder, the metal shell underneath is energized to the negative electrode, so…an electrical short may be possible.
After years development, we have built up a good reputation for high-quality lithium ion battery packs and electric bikes battery at very attractive prices. Our Quality system satisfies the international standards of ISO 9001:2008.
This is list of the best performing, best value electric bikes for 2017 / 2018. For each category I list two models, the first recommendation is based on performance and the second is based on affordability. As you explore the list and get to know EBR, check out the ebike community forum for more personalized feedback. Share your height, weight, budget and intended use (along with bikes you like) to get advice from actual owners and moderators.
13. Winners will be emailed directly by the marketing manager. Must respond within a week. Winner may also be announced on Facebook. 14. Sponsor: The Sponsor of the Sweepstakes is Electric Bike Technologies LLC, 951 River Road, Croydon, PA, United States;
According to some quick research I did, a city block is about 100,000 square feet which means that you can fit 17 blocks per mile. Given your round trip distance of 14 blocks… that’s way less than one mile and in my experience the new EVO line of Easy Motion bikes (which have ~417 watt hour batteries) will get upwards of 15 miles per charge even after hundreds of uses and on uneven terrain. Of course, your weight and the hills and wind all have a factor but you should be very good for just a mile or two of use.
Spot welders for batteries aren’t the same as most home spot welders. Unlike the large jaw spot welders for home workshops, battery spot welders have the electrodes on the same side. I’ve never seen them for sale in the US, but they can be found pretty easily on eBay and other international commerce websites. My full time use welder is a fairly simple model that I got here. A highly recommended source for a slightly nicer spot welder design (pictured below) with both mounted and handheld electrodes can be found here.
I have a homemade battery made up of 84 NCR18650b cells that I bought (in other words, I didn’t make the battery myself). Anyway, I lost the charger for it at Burning Man, and now I’m going nuts trying to figure out what kind of charger to buy. The arrangement of the batteries is odd. Part of the battery looks pretty straight forward in what I believe is a 8s6p design, but the rest look different… they are set up like a 4×3 rectangle framed by 2 L’s. I would have happily uploaded a picture, but that doesn’t seem possible. Is there anyway I can send you a picture to show you what I mean?
Wear safety goggles. Seriously. Don’t skip this one. During the process of spot welding it is not at all uncommon for sparks to fly. Skip the safety glasses and head for chemistry lab style goggles if you have them – you’ll want the wrap around protection when the sparks start bouncing. You’ve only got two eyes; protect them. I’d rather lose an arm than an eye. Oh, speaking of arms, I’d recommend long sleeves. Those sparks hurt when they come to rest on your wrists and forearms.
Small hard-cased A123 cells (about the size of a “C” battery) have been salvaged out of power drill packs, car battery packs etc, and have made it into the hands of e-bike DIYers who solder them together in series and in parallel to construct a pack http://huntnbike.com enough and powerful enough to power an e-bike.
Sunstar is based in Japan, and here is a PDF of their most recent mid drive motor system. Sunstar has a 2001 patent on this drive, and they are suing Bafang in Germany over the BBS01/BBS02 system that has recently become popular. That patent is 13 years old, so perhaps Bafang felt they were on safe legal ground in by copying it?
It’s all good Ben, choosing an ebike based solely on the motor is tough because the strength and design of each motor varies. I wouldn’t avoid geared hubs just because there’s more potential for wear over time. I just tested one today that is 5+ years old and still going strong (along with the battery pack). I’ll look for your post in the forums and try to help out if you provide your height, weight, terrain and desired budget 🙂
Latest BBS02 48V 750W 8Fun Bafang Mid Drive Ebike Conversion Kit BB:68mm Electric Bicycle. – BBS02 Mid-Drive Motor: 1 pc. – Power: 750W. ≤1.8 127±6 750W 112±6 ≥78% ≥60 ≤20.5 ≥120 ≥80% Kits Included. – Left Crank Right Crank: each 1 pc.
To wire the BMS, we first need to determine which of the sense wires (the many thin wires) is the first one (destined for the first parallel group). Look for the wires to be numbered on one side the board. Mine is on the backside of the board and I forgot to take a picture of it before installing it, but trust me that I took note of which end the sense wires start on. You don’t want to make a mistake and connect the sense wires starting in the wrong direction.
Most commercially available 36V packs are around 10Ah, meaning our pack will be just a bit smaller. We could have also gone with a 4p configuration giving us 11.6 Ah, which would have been a slightly bigger and more expensive pack. The final capacity is totally defined by your own needs. Bigger isn’t always better, especially if you’re fitting a battery into tight spaces.