Electric Scooter Battery: AppScooter Modular Battery Update

12/07/2018Engineering, Frontpage

Things are heating up in the engineering and design department at Etergo as the efforts to maximise the bang for your buck continue. This week we would like to share an update regarding the innovative modular battery pack of AppScooter. The electric scooter battery is receiving multiple changes with the purpose of improving both ergonomics and performance.

AppScooter is already the most versatile electric scooter in the category, offering a customisable experience (and price) based on your mobility needs. These new changes are further improving on this and also making the battery easier to remove and more portable. The guiding principle of the development process, and particularly in this case, is to make all aspects of AppScooter even more user-friendly and convenient for daily use.

Electric Scooter Battery: Obstacles of Previous Battery Design

Until now, the battery pack of the electric scooter battery design consisted of six modules placed perpendicularly to the drive direction which could be pulled out of the frame as a single, connected battery pack. This presented the need for extensive mechanical and electrical engineering to make the connections between all six modules sturdy enough to be removed from AppScooter by pulling on the one module closest to the Buddy Space access point. The increased engineering effort and strength requirements for such a configuration therefore would increase the cost to achieve these very particular needs, but also would take up more space and would lower the number of cells per module. The electric scooter battery modules were already quite small so it would have created a further disadvantage by decreasing the range. Another, possibly even greater, problem with the initial design was the weight of the total modular battery pack. Six modules required quite some extra material for the connections and exceeded the European maximum weight allowance employees are permitted to carry which is 23 kg. To work around that it would have been necessary to design integrated tooling for portability such as wheels or a backpack-like carrying feature which would make it quite complicated for the engineering and manufacturing process but still was not a good solution for carrying six modules.

Electric Scooter Battery: Change of Direction

Taking all these factors into consideration, our industrial designers and engineers decided to look at different options such as to combine two modules into one, making the total battery pack consist of three modules in total. The issue with this concept was that it would take up more space and subsequently reduce the Buddy Space. Adding to this problem were the handles required for carrying the modules which were difficult to fit into such a limited space. Furthermore, such a configuration required the modules to fit together at an angle and still would not solve the problem of sturdiness and connecting those three modules together. This would be both difficult to produce and quite costly for manufacturing and would increase the price of the battery pack. The manufacturing difficulties trickle down into further drawbacks as the energy density would be less. The plus point of such an approach is that it requires less electronics to power it as it would not require six individual battery management systems (BMS), but three slightly more expensive ones. Unfortunately, this was not a well-rounded solution as it posed too many challenges for manufacturing. This led us back to brainstorming and to looking for the appropriate solution for the space available. The desired result, a battery pack with a higher energy density per kilogramme which is easy to carry and cheaper per kilometre for the customer.

Electric Scooter Battery: Solution and Improvements

After extensive research into the best design and configuration to achieve the goals we had set ourselves the solution was found, three banana-shaped battery modules aligned with the drive direction. This enables the rider to remove each module effortlessly and makes them easier to carry with a weight of approximately 7.5 kg per module. The new electric scooter battery design leaves plenty of space to build the connectors for each module, price per kilometre is less and it is much easier to manufacture.

Manufacturability was a major deciding factor in this new direction as the previous electric scooter battery design proved quite difficult in this respect. This new configuration was also discussed with Etergo’s battery partners in order to receive their expert input as they had raised some concerns about the previous design which had confirmed that we needed to go in a different direction. Our partners were very positive about the new design and configuration, both from a manufacturing point of view, but also that it would fulfill the strength requirements for the modules. The new battery design also allows the possibility to have aluminium side panels which would benefit possible future higher power versions if heat became an issue and there could even be the possibility of forced air cooling in that area to assist with heat dissipation. The cost of producing these new battery modules will slightly increase with this alternate battery design because of the improvements on the entirety of build materials, nevertheless still remaining within our price targets. The slight increase in production cost however was considered a good compromise as we could offer more range with the base version for the same end price and it would be easier for the rider to carry on their shoulder which would not have been possible with the previous version.

Owing to the new improved design, now each battery module will be equipped with a carrying handle to make charging it remotely in your home or office easy and convenient, eliminating the need to park your AppScooter near a power socket. Access to the modular battery pack is unchanged and it will be accessible from the Buddy Space, no tools required.

Another handy new feature is the ability to charge a single battery module at a time even when your AppScooter is equipped with an extended battery pack, without needing to remove the other modules. Simply remove the battery module you wish to charge then slide it back into place next to the others once you are done.

Electric Scooter Battery: Range

As previously mentioned, the shape of the electric scooter battery has been lengthened and placed longitudinally within the frame, decreasing the battery modules from six to three. This single fundamental change increases the capacity of each battery module and subsequently its range is extended by approximately 60%. Our previous estimations of total range with a full battery pack was 400km, however this was not realistic as it would require ideal conditions, tail wind etc and actually was not easily achievable. With the new design in mind and more realistic riding conditions we estimate a total range of approximately 240km which is currently more than double what our competitors are offering and one of the highest ranges in the segment.

Our new estimations are more solid, certainly achievable in normal riding conditions and we prefer to aim for a range that customers can trust. Our User Interface and User Experience designers are currently working on a tool for customers to calculate their range according to their specific conditions. With this new Range Calculator, Etergo will offer customers a very important tool to use when deciding how many battery modules will meet their personal mobility needs or before heading out on their AppScooter. In the ongoing development of this tool, we have reached a model that will give us a more accurate range estimation which is significantly more than what you would get on a full tank of a petrol scooter.

Keeping Our Promise

These new changes to Etergo’s modular battery pack will not affect the current purchase price as Etergo strives to offer the best value to its customers and reward them for believing in AppScooter and a better way of mobility.

We expect to have more updates soon as the industrial designers and engineers at Etergo continue to fine-tune the innovative AppScooter. For more information on Etergo, AppScooter or the electric scooter battery please visit www.etergo.com.