Extending An E-Bike Range From Good To Wheelie Good

Battery pack of e-bike being welded

It may not look like it in some parts of the world, but electric vehicles are gaining more and more market share over traditional forms of transportation. The fastest-growing segment is the e-bike, which some say are growing at 16x the rate of conventional bikes (which have grown at 15% during the pandemic). [Jacques Mattheij] rides an S-Pedelec, which is a sort of cross between a moped and an e-bike. There were a few downsides, and one of those was the pitiful range, which needed to be significantly upgraded.

The S-Pedelec that [Jacques] purchased is technically considered a moped, which means it needs to ride in traffic. The 500 watt-hour battery would only take him 45km (~28 miles) on a good day, which isn’t too bad but a problem if your battery runs down while in traffic, struggling to pedal a big heavy bicycle-like thing at car speed. You can swap batteries quickly, but carrying large unsecured extra batteries is a pain, and you need to stop to change them.

There were a few challenges to adding more batteries. The onboard BMS (battery management system) was incredibly picky with DRM and fussy about how many extra cells he could add. The solution that [Jacques] went with was to add an external balancer. This allowed him to add as many cells as he wanted while keeping the BMS happy. The battery geometry is a little wonky as he wanted to keep the pack within the frame. Putting it over the rear wheel would shift the center of gravity higher, changing the bike’s handling. After significant research and preparation, [Jacques] welded his custom battery back together with a spot welder. The final capacity came in at 2150wh (much better than the initial 500wh). An added benefit of the extra range is the higher speed, as the bike stays in the higher voltage domain for much longer. In eco mode, it can do 500km or 180km at full power.

It’s awe-inspiring, and we’re looking forward to seeing more e-bikes in the future. Maybe one day we’ll have tesla coil wireless e-bikes, but until then, we need to make do with battery packs.

25 thoughts on “Extending An E-Bike Range From Good To Wheelie Good

  1. Electric vehicles have been and still are a dead end. Already the infrastructure is struggling to keep up with demand when everyone goes to make a cup of tea during evening news. If it gets loaded with millions of electric cars (that is multi-kW loads) it will end in either: grid collapse and blackouts; price of electricity approaching the price of petrol; electric cars going nowhere (literally) because “smart chargers” do not allow charging “just now” (since 2 weeks).

    1. Really was expecting this to end with valid concern expressed over limited supply of lithium used in rechargeable tech. Instead, you zagged down the unexpected route of faulting the electrical grid. Huh. That was weird. This eBike guy has modified something that has a power-to-weight ratio that makes decentralized solar very realistic. For instance, my friend commutes everyday on an eBike he 100% charges off a couple solar panels at his house. I happened to be doing some casual research into solar charging eBikes and came across this proof-of-concept where a guy implausibly generates more power than he uses trailing 3 panels behind an extremely inefficient eBike he hacked together in three hours– https://youtu.be/7EyRqQhuwio

      The obstacle to displacing ICE with electric isn’t the grid. It’s always been the cost and rarity of the storage medium materials.

      1. I ride an Ebike and it makes commuting as easy as driving my car. So it is totally viable for the general public for a significant number of people.
        I worry though about how diligent people will be about recycling the batteries and how many will end up in the landfill.
        This is especially a concern as they get even cheaper and hence more abundant.
        Bikes are still seen as a hobby and basically toys by most people. They just throw them in the trash when they are done with them.

      2. Thanks to bring real comment. You are well informed about actual facts. I was loosing hope. We have a lot of free good information and some people , they always prefer write forward those expired problems faced a decade ago. Just for annoying others. Please, stop spreading old stuff about technology

    2. Gasoline vehicles are a dead end. As more and more people move to electric the cost of transporting and storing liquid fuel will result in a death spiral leaving ice fanatics holding the bag.

    3. Grid load levelling has always been a thing, and always should be – if you are oversupplying so much by burning fuel that costs you a fortune in waste, bad for the power company so of course they are going to only burn about as much as demanded, and the other way if you have a vast oversupply of renewables that don’t cost you anything more you use it – push more of it the pumped hydro stations, everyone with an EV gets paid to charge it, fire up another smelter etc – just because supply exceeded the ‘demand’ doesn’t mean there isn’t some use for it – you just wouldn’t choose to pay normal or peak time rates to do so…

      EV are if anything a boon to the grid – being smart enough they can know when to charge fast or slow etc, and many EV home charge setups can do electricity trading which balances the grid and makes the owner a little money in the process.

      Electric vehicles have never been a dead end, and could have seen much more use through the last few decade if the oil companies didn’t sit on all the patent. The only reason ICE really takes off is in the early years when almost all cars were electric battery tech hasn’t really gotten great ranges (though early ICE were worse, breaking down or running out of fuel in short order), fuel cells are no more than experiments, so as oil becomes cheaper to extract and refine with more and more of it found, and the unreliable, stinking messes of the early ICE engines progress towards the functional almost reliable engines of the 40’s it makes the easy choice at the time, petrol is soo cheap why use anything else?

    4. In most places, electricity is already more expensive than petrol (per kWh, which is slightly misleading as petrol is chemical potential and normally ends up as heat, electricity is work – so you can use electricity more efficiently more easily than you can use petrol – but this is already factored into MPG/MPGe for transport)
      Petrol has about 9.5kWh/Litre, so to use UK prices (electricity at ~15p/kWh), that’s like electricity costing £1.42/litre-of-petrol-equivalent (so more than petrol until very recently, and only equal now because the price cap rate is lagging the wholesale price)

      Also does anyone know how to see the UK price cap in p/kWh? On the ofgem website it only has it in pounds-per-time-for-average-user, which is useless if you aren’t an average user. And their breakdown page has a breakdown of supply-side costs, not of how much of the average-user estimate is from connection cost, per-unit cost, electricity, gas, etc
      Stating it in pounds-per-year also makes it seem like the total energy bill is capped regardless of usage, which is a really bad way to incentivise people to use less fuel, especially as the least thermodynamically-aware people are also the most likely to hear ”

      And most fast-charging things are much pricier (28p/kWh for a tesla supercharger in the UK, or £2.66/litre-of-petrol-equivalent)

    5. This simply isn’t true with ebikes and charging their batteries. What you just said about electric vehicles is so wrong it’s *fractally* and *recursively* wrong.

      Most ebikes don’t have fast high amperage chargers, and in fact smaller ebike batteries are supposed to be charged as slow as possible for best battery health and long life.

      Your average stock ebike charger is only 1 amp, while some upgraded “fast” chargers can be 2-5 amps, while some really high performance chargers peak at around 10 amps, but these are rare and they’re usually smart chargers that modulate the input amperage.

      Further, the current industry average for MPGe (miles per gallon equivalent) is about 1000 MPGe. People who pedal more or use more efficient converted ebikes get much more than that compared to fat tire “comfort” ebikes and pedelecs that are more moped than bicycle.

      I did the math on this a couple of weeks ago and you want to know how much it costs me to fully charge my fairly large ebike battery? 5 US cents. Maybe 8 cents. Not a typo, that’s 0.05 to 0.08 USD to per charge for about 40 miles of range. I only have to charge it 2-3 times per week, and it’s never fully depleted anyway because my longest rides are about 20-25 miles, with 15 miles being more common.

      This is less power than a 100 watt incandescent light bulb. It’s way less power than an electric kettle, be it a US 120 V kettle or a British 220-240 V kettle. It’s way less power than a refrigerator, or a washer or dryer.

      My charger uses so little power it’s basically a rounding error on the total power bill for the house even if I completely depleted the battery and charged it every day.

      Think about this for a second: For the 2500 miles I’ve put on my ebike since I started riding it I have maybe used 10-20 dollars worth of grid electricity over 2 years! In MPGe terms I’ve used maybe 2-3 gallons of gas for TWO YEARS of commuting, grocery runs and fun rides.

      Ebikes are now the single most efficient powered vehicle on the planet. The only thing more efficient than an ebike is a regular bike because unpowered bikes were already the number one most efficient vehicle on the planet, watt for watt, mile for mile.

      Considering the infrastructure needed to fuel ICE vehicles your average gas burning car uses more electricity per mile than an ebike does if you add up the electrical costs of running a service station and keeping the lights on, the electric pumps required for pumping fuel, the power tools for car maintenance and that’s long before you start comparing energy costs for manufacturing, road building and everything else that support gas powered vehicles.

      Ebikes are so energy efficient that if vacuum out your car at a car wash with one of those high powered car vacs for 15 minutes and fueled up a couple of times you’ve probably used more power than my ebike uses in an entire month of riding and commuting.

      Electric vehicles aren’t a dead end. They aren’t going away. The adoption rate is only increasing rapidly. I built my ebike and started riding it over two years ago and on my local trails ebikes went from about 1 in 10 bikes to something like 7 in 10 bikes. The growth rate of ebikes has been unprecedented over the last few years.

      Basically everyone I know now wants an ebike and is making plans to buy or build one.

      The electrical grid is going to be fine. Charging ebikes and other electric vehicles might even save electricity and lower the grid loads if less people have to rely on petrol/gas to get around if you start adding up all the real world electrical power costs and loads of processing, transporting and delivering fuel.

      As for me? I’m looking to get solar panels to take my ebike entirely off grid, and I’m not the only one. I’ve been making plans to get a portable, packable folding panel and charge controller that can charge my ebike battery just as fast as a plug in charger. Eventually I want to be able to go on long range ebike camping tours where I don’t have to ever worry about ever finding an outlet. People are already doing this and it’s not even that expensive any more.

    1. A Honda GX35 is 3.3kg for ~1kW of power output, and 0.7kg/kWh thereafter. If you had a hub electric motor, you could charge the batteries while you ran the petrol motor up hills, and probably just need about a 30% duty cycle. An issue is the high gear ratio needed at 7000rpm: 25x-50x.
      Alternatively make a series hybrid,using a BLDC motor as a generator (300g-500g), and GX25 or GX35 motor. This would give ~350W for the traction motor + ~600W to charge the battery at 1C-2C rate

  2. I am not sure but feel that’s too many cells in parallel. If not out of the same production run (not from China) and matched perfectly they will create problems down the road. I always wonder when people use used laptop cells what imbalance happens. Tesla’s cells are individually fuse wire connected in parallel so if one cell goes nil the rest don’t blow that one up. Load balancing can compensate in the whole stack.

    This is the first time I’ve heard that any moped can keep up with traffic unless the route is 20 miles per hour. 25 and higher around here, they are always lagging.

    Can you hold your gas powered transportation over your head or even pick it up? Tread lightly whilst on Earth, others have to come.

      1. You’re talking about “imbalance” regarding voltage. He’s talking about “imbalance” regarding function, such as a cell developing an internal short.

        Regarding echodelta’s statement about moped speed: I’ve seen some stand-up scooters blow by me at over 25 miles per hour (while I was bicycling). Feels like being passed by a car that is driving too close.

    1. Those are very optimistic numbers, they’re claiming to be consuming something like 5-12 Wh/km. For a light ebike with a human pedaling, this might be achievable. More commonly ebikes will be consuming between 15-25 Wh/km, especially ebikes with big, heavy batteries.

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