via BikeEurope HSINCHU, Taiwan – It sounds like a fairy tale; e-bike batteries that last as long as the e-bike itself. A lifetime of over ten years is within reach. New cell technology also brings batteries capable of much more pedal-supported mileage. And it already comes in 2018. All this is thanks to Tesla.
That Tesla is behind revolutionized batteries for electric bicycles has all to do with the recent changes at the leading battery cell makers Panasonic, Sony, Samsung and LG. Together these four make out some 80% of the world production of battery cells.
Like penlight batteries
These cells are like penlight batteries commonly used in every household. When connected lots of these cylindrical shaped cells make an e-bike battery when of course integrated technology is added like a Battery Management System (BMS).
Changes at IT industry
The mentioned four cell makers used to supply huge numbers of cylindrical shaped cells to the IT industry. However, this industry changed completely from using cylindrical shaped cells to flat shaped batteries which are now used in laptops, tablets and smartphones. A small part of that lost sales was compensated by batteries for e-bikes and other Light Electric Vehicles. However, that sales was too small for Panasonic, Sony, Samsung and LG to invest in the development of new cell technology.
Tesla placing huge orders
Until Tesla knocked on their doors placing huge orders for cylindrical shaped cells. It is in particular Tesla’s newest Model 3 e-car that pushed battery cell makers to new highs. This affordable e-car (retailing for about 35,000 USD) needed a much extended range at smaller dimensions and weight. This called for new technology. At first the battery cell makers were able to add capacity to the currently commonly used 18650 cells. According to GM Mo-Hua Yang of Taiwan based battery maker HiTech Energy, two years ago such a 18650 had a capacity of 2.2Ah. Now it stands at 3.5Ah. More capacity however called for a new cell.
New 21700 battery cell
At Eurobike of last September that new 21700 battery cell appeared on the horizon. No not as a bright light that catched everybody’s attention. This new phenomena wasn’t even on display. It was only mentioned in a press release by BMZ which is Europe’s largest battery maker. BMZ boss Sven Bauer explained to Bike Europe the revolution this new cell will bring to electric bicycles. In particular as the 21700 cell not only offers a much prolonged lifetime but also batteries with a much bigger capacity for more power and pedal-supported mileage.
New standard in e-bike batteries
BMZ is not the only battery maker convinced of the extraordinary features the 21700 battery cell brings to e-bikes. Taiwan based HiTech Energy even says that it will be the new standard in e-bike batteries. And that this new standard will already be there in 2018. So, what’s 21700?
Bigger size; bigger output
It’s a cell of a new format: instead of a 18650 (18mm diameter and 65mm high) cell size the 21700 cell is 21mm diameter and 70mm high. The bigger size is bringing a bigger output; up to 4.8Ah. With that capacity the battery lifetime is extended from the current some 500 charging cycles up to 1,500 to 2,000 cycles.
Less charging, prolonged lifetime
These up to 2,000 charging cycles forms the basis for a much prolonged lifetime. In particular as recharging kills batteries, states BMZ MD Bauer. “As there is less need to constantly re-charge batteries the 21700 cells offer a much increased battery life.”
New standard in 2018
GM Mo-Hua Yang of Taiwan based battery maker HiTech Energy says the same on e-bike batteries made with 21700 cells. But he adds that there’s also another much needed factor that comes into play. And this is in particular needed with rapidly increasing sales of electric Mountainbikes; batteries that can offer more power and range. Yang says, “Smaller batteries offering 1,500 to 2,000 charging cycles as well as 700Wh will be the new standard in 2018.”