Battery capability is a vital issue when buying an eMTB. Nonetheless, many bike producers aren’t totally sincere in regards to the precise capability of their batteries. On this article, we’ll discover the impression of this problem, and clarify why producers are considerably compelled to govern figures, and why we advocate for a unified normal.
The controversy about battery capacities has been a heated one since day one within the eMTB section, and nonetheless stays one of many largest promoting factors for bike producers – as our annual reader survey additionally confirmed. This makes it all of the extra necessary for producers to remain aggressive and sustain with present developments. Initially, batteries have been principally mounted externally; as we speak, they’re built-in into the body and sometimes detachable. Almost all e-bike methods additionally supply the choice of including an exterior vary extender. Furthermore, there has by no means been such all kinds of various battery capacities as there’s now. As e-bike rider sorts have gotten extra various, producers try to maintain up and cater to the various wants of various buyer teams. Evidently, bike realised that completely different completely different bike- and rider-types require completely different battery capacities. In different phrases, shoppers are now not restricted to a single battery measurement, which was the case for a very long time as a consequence of a scarcity of choices – as we speak, you will get many bike fashions with completely different battery choices. Fairly cool!
As well as, battery capacities have grown considerably through the years to maintain tempo with more and more highly effective motors. The frequent enemy: vary anxiousness. On the identical time, cell expertise has improved, permitting engineers to squeeze extra battery capability into the identical pack measurement. That is notably necessary for eMTBs, the place dealing with and design are essential standards. Consequently, pack measurement, battery form, and power density are crucial components – and that is exactly the place the issue lies.
Making an attempt to take a crucial have a look at producers’ battery capability specs – usually given in watt-hours (Wh) – would possibly convey again recollections of your final contract with an web supplier. Most individuals are conscious that the marketed community speeds are hardly ever achieved, as they’re conveniently labeled with an “as much as” disclaimer. With e-bike batteries, nevertheless, this isn’t the case, despite the fact that the underlying idea is sort of related.
The issue: Since there aren’t any particular laws on how producers must calculate battery capability, vital variations can come up between manufacturers – even when the precise capability is identical. Tolerance ranges are pushed to the restrict, standardised lab measurements are recontextualised as a result of they supposedly don’t replicate real-world eMTB eventualities. Consequently, various definitions of how a lot capability is really accessible to energy the motor end in complicated figures. When mixed with technical components reminiscent of cell high quality, the subject turns into so complicated that even consultants usually battle to maintain up. Some producers make the most of this complexity. Whereas the figures steadily offered as advertising claims aren’t outright lies, they don’t totally replicate actuality – and producers are properly conscious of this.
Warning, issues are about to get technical: On this article, we’ll concentrate on calculating a battery’s nominal capability. Nominal capability might be decided from standardised measured values that each producer is required to offer. This permits not solely customers but additionally producers to make truthful comparisons. Consequently, many bike manufacturers are calling for nominal capability to develop into the brand new normal for specifying battery capacities. Whereas many producers already comply with this follow, others nonetheless make the most of consumers’ lack of information by inflating their marketed battery capability with undefined claims.
How do you’re employed out the nominal capability of an e-bike battery?
Calculating a battery’s nominal capability isn’t rocket science, and anybody can work it out very quickly. Each battery producer is required to offer the mandatory information straight on the battery itself. All batteries have a nameplate displaying varied technical specs. Moreover, producers usually embody a battery information sheet on their web sites, or in some instances, the knowledge is displayed straight on the web site, as is the case with Bosch.
Motor producers like Bosch, SRAM, Fazua, TQ, and DJI depend on a closed system, which means that anybody utilizing their motors should pair them with their batteries. Consequently, bike manufacturers have little to no affect over the marketed battery capability. It’s a unique story with motor methods from producers like Shimano and Brose, which permit bike manufacturers to pair their drives with third-party batteries, for instance from corporations like Chinese language producer Trendpower or Taiwanese provider Darfon. This permits them to affect not solely the cell sorts, cell association, and the matching housing but additionally the desired battery capability. Widespread examples embody Orbea, Canyon, MERIDA, and Specialised, all of which have bikes of their portfolios with customized batteries.
To calculate the nominal battery capability, you want two values: The primary one is the battery’s rated capability, which is measured in Ampere-hours (Ah). The rated capability can not technically be manipulated, as battery producers are required to specify this worth based on the IEC61960 normal. It’s measured in a standardised laboratory course of and displays the minimal capability of a cell based mostly on the Gaussian regular distribution. In a nutshell, after figuring out the typical worth from the lab measurements, you subtract the tolerance worth to seek out out the minimal assured cell capability. The one problem – and the explanation why producers “technically” can’t cheat – lies within the certification necessities for various markets. In South Korea, for instance, certification requires the “rated capability” to replicate the minimal capability worth. Different markets would settle for the precise common worth. Nonetheless, since practically each cell and battery producer consists of the Korean market of their gross sales technique, the rated capability listed on the nameplate at all times represents the minimal capability worth. This nonetheless leaves room for cheeky producers to interpret the numbers otherwise.
The second worth wanted is the system voltage, which is measured in volts (V). Most motor methods at present accessible in the marketplace, just like the Bosch CX Gen4 and Gen5, the Shimano EP801, SRAM Powertrain, and Brose Drive S Magazine – which is specced on the most recent Specialised Levo mannequin, for instance – use a 36V voltage system. In distinction, the TQ HPR 50 system operates at 50.4V, the Fazua Ride60 system at 43.2V, and the Specialised SL 1.2 at 46.8V.
All this info may also be discovered on the battery’s nameplate. To find out the nominal battery capability, merely multiply the nominal capability by the system voltage. To stop you from having to look the web or run straight to your storage, we’ve completed the analysis for you and compiled a listing of all related, thrilling, and widely-used battery choices.
| Model/Battery | Rated capability | System voltage | Nominal capability | Claimed capability | Deviation between nominal and claimed capability |
|---|---|---|---|---|---|
| SRAM Powertrain 250 Wh (Vary-Extender) | 6,7 Ah | 36 V | 241,2 Wh | 250 Wh | 3,65 % |
| SRAM Powertrain 630 Wh | 16,7 Ah | 36 V | 601,2 Wh | 630 Wh | 4,79 % |
| SRAM Powertrain 720 Wh | 19,6 Ah | 36 V | 705,6 Wh | 720 Wh | 2,04 % |
| Bosch PowerMore 250 (Vary-Extender) | 6,7 Ah | 36 V | 241,2 Wh | 250 Wh | 3,65 % |
| Bosch PowerTube 400 | 11 Ah | 36 V | 396 Wh | 400 Wh | 1,01 % |
| Bosch PowerTube 600 | 16,7 Ah | 36 V | 601,2 Wh | 600 Wh | -0,2 % |
| Bosch PowerTube 650 | 16,7 Ah | 36 V | 601,2 Wh | 620 Wh | 3,96 % |
| Bosch PowerTube 750 | 20,1 Ah | 36 V | 723,6 Wh | 750 Wh | 3,65 % |
| Bosch PowerTube 800 | 22,2 Ah | 36 V | 799,2 Wh | 800 Wh | 0,1 % |
| Shimano BT-EN604-A | 11,6 Ah | 36 V | 417,6 Wh | 418 Wh | 0,1 % |
| Shimano BT-EN605-A | 14 Ah | 36 V | 504 Wh | 504 Wh | 0 % |
| Shimano BT-EN606-A | 17,5 Ah | 36 V | 630 Wh | 630 Wh | 0 % |
| TQ 160 (Vary-Extender) | 2,8 Ah | 50,4 V | 141,1 Wh | 160 Wh | 13,38 % |
| TQ 360 | 6,8 Ah | 50,4 V | 342,7 Wh | 360 Wh | 5,04 % |
| TQ 580 | 11,14 Ah | 50,4 V | 561,5 Wh | 580 Wh | 3,3 % |
| Fazua 430 | 10 Ah | 43,2 V | 432 Wh | 430 Wh | -0,46 % |
| Orbea Rise (Vary-Extender) | 5,6 Ah | 36 V | 201,6 Wh | 210 Wh | 4,17 % |
| Orbea Rise 420 | 11,1 Ah | 36 V | 399,6 Wh | 420 Wh | 5,11 % |
| Orbea Rise 630 | 16,7 Ah | 36 V | 601,2 Wh | 630 Wh | 4,79 % |
| Canyon Trendpower 720 | 19,6 Ah | 36 V | 705,6 Wh | 720 Wh | 2,04 % |
| Canyon Trendpower 900 | 24,5 Ah | 36 V | 882,0 Wh | 900 Wh | 2,04 % |
| MERIDA Trendpower (Vary-Extender) | 9,8 Ah | 36 V | 352,8 Wh | 360 Wh | 2,04 % |
| MERIDA Trendpower 600 | 15,99 Ah | 36 V | 575,6 Wh | 600 Wh | 4,23 % |
| MERIDA Trendpower 750 | 19,8 Ah | 36 V | 712,8 Wh | 750 Wh | 5,22 % |
| DJI Avinox 600 | 16,7 Ah | 36 V | 601,2 Wh | 600 Wh | -0,2 % |
| DJI Avinox 800 | 22,3 Ah | 36 V | 802,8 Wh | 800 Wh | -0,35 % |
| Specialised Turbo Levo SL (Vary-Extender) | 3,35 Ah | 46,8 V | 156,8 Wh | 160 Wh | 2,05 % |
| Specialised Turbo Levo SL | 6,7 Ah | 46,8 V | 313,6 Wh | 320 Wh | 2,05 % |
| Specialised Turbo Levo | 19 Ah | 36 V | 684 Wh | 700 Wh | 2,34 % |
How dangerous is the battery confusion actually?
It is a query everybody should reply for themselves, because it is determined by how a lot significance you place on precise capability and the way usually you totally drain your battery. Normally, the variations in battery capability quantity to only some %. Nonetheless, relying on the battery measurement, these deviations can shortly exceed 30 Wh, which may very well be essential in figuring out whether or not you make it house on a protracted journey. Moreover, completely different batteries could have the identical nominal capability however are marketed otherwise by producers. When you’re sitting on the fence between two such bikes, this issue would possibly wrongly affect your buy resolution.
Producers are properly conscious of this problem and intently analyse their rivals’ specs. To stay aggressive, they usually really feel compelled to regulate and even improve their very own capability figures. Every producer should determine whether or not to play this sport to outlive within the powerful present market. That is one cause why many producers are pissed off by inconsistent capability claims. A noteworthy instance is Bosch, which has taken the lead by specifying the nominal capability of their new batteries – 600 Wh and 800 Wh – which wasn’t the case with their older fashions. Bike producers like MERIDA have additionally indicated that they plan to align extra intently with nominal capability requirements sooner or later.
After all, nominal battery capability is only one piece of the puzzle, and plenty of different components affect the “usable capability” of a battery pack. One essential issue is the standard of the cells – a element that’s usually exhausting for purchasers to guage and even perceive. Two battery packs could have the identical nominal capability however use different-quality cells. Excessive-quality cells have a better most discharge depth, which means that they supply extra usable capability to energy the motor. In distinction, cheaper cells could not help deep discharges and require a better remaining voltage, which means much less usable capability and a smaller vary. Moreover, producers differ in how a lot capability they reserve for capabilities like lights, shows, and digital shifting. This additionally impacts the quantity of power accessible for propulsion.
What do producers say in regards to the battery confusion?
Evidently, we requested all of the producers listed within the desk above for a press release. Not all of them reached out for a remark, however we’ll replace the article ought to we obtain extra responses.
Our claimed capability is usually greater than the nominal capability as a result of the rated capability is measured beneath standardised check situations, which regularly differ from real-world utilization. For our claimed capability, we comply with the capability specs supplied by cell producers: for instance, our 600Wh battery incorporates 30 cells, every with a Watt-hour ranking of 20 Wh. Deviations from the nominal capability primarily outcome from checks performed beneath worst-case situations, generally used for figuring out the rated capability. Making certain that the measured nominal capability aligns with the claimed capability is a central precedence for us. Clear and dependable specs are essential for constructing buyer belief. Due to this fact, we work intently with our battery companions to satisfy these requirements collectively. Our new Bosch PT600 and PT800 batteries already adjust to this method. Likewise, our new Shimano batteries for MY26 could have a nominal capability that precisely matches the claimed capability. Benjamin Diemer – CEO MERIDA R&D
As one of many world’s main expertise corporations, DJI is dedicated to offering best-in-class innovation and the DJI Avinox Drive System isn’t any exception. On the subject of batteries, precise battery capability is determined by a number of components reminiscent of the true use eventualities of the battery and likewise the temperature. To outline a battery’s core capability, the charging voltage, present and temperature should be considered. A brand new battery is often charged to 4.2V utilizing a 0.2C present at 25°C, adopted by discharging to 2.5V. For the Avinox Drive System’s LG M58T battery, the usual battery core capability is 20.28Wh, with a minimal capability of 20.0Wh. We calculate the precise pack capability, based mostly on a 3% remaining energy calculation, is 786.86Wh, which represents 98.36% of its nominal 800Wh ranking. Nonetheless, in real-world functions, discharge currents are usually greater than the 0.2C price, which may end up in a decreased most discharge capability—usually falling under 800Wh, and in some instances as little as 750Wh, relying on the discharge present. Moreover, temperature performs a big position in discharge capability, with decrease temperatures additional impacting the power to succeed in nominal capability. This variance between nominal and precise capability, defined above, is frequent in battery metrics. To current extra favorable efficiency metrics, some producers could use the usual capability as their declared worth. For many functions, the LG M58T battery is rated at 800Wh, delivering dependable efficiency with these concerns in thoughts. Ferdinand Wolf – Product Expertise Director DJI
Our objective is to offer most clear and sensible info for customers. The label on Bosch eBike batteries usually consists of three values. The rated capability, laid out in ampere-hours (Ah), corresponds to the minimal worth outlined by the IEC61960 normal that the battery should obtain. The battery voltage, laid out in volts (V), stays largely fixed. The power content material, laid out in watt-hours (Wh), represents the everyday nominal worth and signifies the capability the battery delivers in typical use. In line with the IEC61960 normal, cell producers are required to specify the minimal capability (Ah) of their cells. Regardless of constant high quality and efficiency, this worth can range barely between cells from completely different producers. The minimal worth is used to calculate the nominal capability on the battery stage. In follow, nevertheless, the power specification in Wh is normally barely greater than the calculated outcome based mostly on rated capability (Ah) and battery voltage (V). For that reason, the specs on the batteries could differ barely. Dr. Vikram Godbole – Senior Produktmanager Bosch eBike Techniques
Cell capability (Ah) is set beneath laboratory situations following particular check procedures. Two completely different capacities are calculated based mostly on completely different check situations: the rated capability (Ah) and the everyday capability (Ah), with the latter at all times being barely greater. The battery pack capability (Ah) worth is obtained by multiplying the cell capability by the pack configuration (the variety of parallel branches). For all future SBC battery fashions, rated and typical capability, in addition to the corresponding power in Wh (capability multiplied by the nominal voltage), might be written on the battery label for optimum transparency. Extra attentive riders could understand that these values are usually not obtained when discharging the battery to 0%, based on the show. It’s because a small portion of the capability is reserved. This reserved capability ensures the optimum operate of the battery administration system (BMS) beneath all circumstances. Moreover, it permits an uncompromised using expertise proper up till 0% after which retains the lights operational for an extra 2 hours to maintain you protected at evening – even when the battery is displaying empty. SBC is at all times optimizing this reserved capability to ship the largest quantity of energy for rider (motor) help whereas guaranteeing the protected and clean operation of the system. Simon Maksay – Battery Engineer Specialised Bicycle Elements
5.8Ah is the utmost rated capability for every cell. We now have chosen to make use of the utmost capability measurement to find out the capability of every battery as a result of we really feel it’s a fixed measure. Our objective is to stay to 1 fashion of measurement so shoppers are capable of evaluate generations of our bikes to 1 one other. One other necessary measure is the accessible cost, i.e. how a lot the motor can use. We spend a variety of time working in our laboratory on this quantity and with Rise we’ve been capable of create a management software program that is ready to safely use rather more of the accessible cost, which means a for much longer vary. On the brand new technology of batteries, the cells we’re utilizing are 21700 5.8Ah cells, which signifies that each cell offers 5.8Ah of capability. Relying on the battery we’ve a unique quantity of 10 cells packs. The 630Wh primary battery for instance has 3 packs, the 420Wh primary battery 2 pack, and the 210Wh vary extender 1 pack. To know the true capability, we multiply the battery rigidity (36V) by the variety of cell packs (3, 2, or 1) and by the cell capability (5.8Ah). This manner we all know the true capability of the battery. Markel Uriarte – International MTB Product Supervisor ORBEA
Conclusions about precise battery capacities
There are numerous cheap explanations for a way battery capability is set for advertising functions. Nonetheless, so long as so many various approaches are used, evaluating battery capacities straight is unfair and, fairly frankly, pointless. Due to this fact, we want a firmly established and clear methodology that each one related battery producers comply with. The tactic of calculating nominal capability seems to be probably the most sensible answer at this stage. The efforts of many producers to implement and use it as a reference worth already present that it’s steadily turning into an business normal.
In our future checks, we can even point out these specs to assist promote this normal. If you wish to be taught extra about e-bike motor methods and associated terminology, you should definitely try our detailed e-bike motor comparability check.
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Phrases: Peter Walker Photographs: Various
