lnunell

The main focus for us is a reduction in price of the charging hardware but maintaining the same power output and quality. Our system is designed to be paralleled with hundreds of units. so it is well placed to deal with higher capacity battery packs. Leigh

Hi All, A progress report on the battery systems including the BMS and the Charger. We have a prototype system running with all of the metrics in the green, It is currently in a much larger box to test thermals but the system is running comfortably at 600watts output, the initial aim is to have these units running in parallel so we can match demand with different size battery packs. The 600 W version will charge a 150Wh pack in 15 minutes to full (10 minutes to 80%). But we can combine two of these chargers in parallel to get 1200 watts for a 15 minute charge on 300Wh (10 minutes to 80%) We have designed our architecture to be infinitely expandable so we will be able to charge as many bike (or as large a pack as possible) Our current test results are really promising: 600W output 30 degree Celsius temp rise (well withing boundaries) 90% efficiency at 57.6v Power Factor of 1. Number of components used 40% less than Half Bridge systems 0 Electrolytic capacitors used (longer life) We are now switching our BMS and control systems over to fully digital to reduce size, cost and increase control over the analysis of the battery health. We think we will have our system on several bikes before the end of May and validated before end of august. Thanks, Leigh.

Our system logs charge data in the battery itself for diagnostics.

So this is unfortunately not for you my friend, if you are looking for a battery that is 1/2 the weight and twice the distance you are looking for a battery that is roughly 4x what is capable today, this is another decade away.

We can configure our system to do 36v packs, the reason why we chose 48v is it is better efficiencies all around compared with 36v. A 360w pack at 36v will perform worse than a 360w 48v pack

The test houses we have spoken to in the UK deal with 48v nominal, and as long as it is under 60v during peak charging. Not sure where these other testing houses are but they are mistaken.

Yes, it is more to do with the initial configuration at this point.

Here is another question: Bottle rack mount or pannier mount, which is the most popular? We are designing for bottle mount but have scope to have two versions if demand is there.

All of this is in early prototype stage so we have not certified it yet (we are focusing on the charger) but yes it will be EN 15194 when we finish.

Yep completely agree that you need docking stations for hire schemes and that is what we are focusing on for our own hire scheme. The only reason I can see why they may stop talking to you once you say that is they probably see limited number of sales for more effort. Silly really.

We have not really focused on size and implementation at the moment, we are currently working about 9cm x 9cm x 30cm size of the chargers, so they can be either separate or built into a docking station. If they are in docking stations they can also be easily paralleled up for more power output. The three things we are focusing on with our architecture is, lowest price per watt, efficiency and reduction in bill of materials. Thanks,

We know the answer so don't worry about that :-)

We have been working with systems up to 60v for some time now, the CE and UL standard for high voltage is >60v DC so as long as you work below this during charging then you are fine. This applies the same for the EN 15194 standards as far as we have experienced. Regarding the higher capacity packs, yes we can go higher, we should be able to charge a 450wh pack in under 30 minutes, the problem you have is then diminishing returns on the size of the pack in Wh vs the miles range. Once you go beyond 400wh packs you will see a large drop off due to the weight of the system. We have been focusing more in efficiency gains and high quality and efficiency BMS systems to maximise the potential of the power already in the pack. Thanks,

Update! I wanted to give you all an update on our progress and what we are expecting to achieve in the next 12 months before launch. We have sized up 3 battery packs for a 48 volt system, a 132wh pack (for scooters), a 264wh pack for Ebikes and a 396wh pack for extended range. One of the main advantages of running at 48 volt (well 57.6v when fully charged) is the efficiency is higher in the whole system, we are running several % higher efficiency on the motors, >88% efficiency on the charger and our test bench is running beyond expectations. We have several versions of our charger running now but in a very 'dirty prototype' stage and have received grant funding to develop the system to a fully running system (mainly the battery management and analysis system). We have estimates for our charging speed that are pretty much on par with what we estimated: We have a 900 watt charger estimate with our 48v system looking like it will be 20 amp output (20 amp @ 57.6v) Our 132wh pack <10 minute to charge to 100% Our 264wh pack <20 minute to charge to 100% Our 396wh pack <30 minute to charge to 100% We think that the pricing will be just below the cost of the Bosch system for equivalent battery sizes but with fast charging, as we are using the highest quality components to keep the efficiency high and not cheap components and parts that we have witnessed with most of the Chinese charger versions. Let me know if you have any questions so far. Thanks!