Recumbent hybrid Electric transport by CEL

[CEL-UK]

Hi,
My name is Chris Elsworthy, I’m director of the cordless power tool company CEL, you might have seen our products around which include the POWER8 workshop, multi2PRO, to mention a couple, or from our appearance in the BBC series Dragons Den.

I’ve always been interested in electric transport and also cycling, and a few months ago decided to investigate the possibility of using some of our cordless power tool batteries to make a daily useable transport device.

After a little research and a bit of idea bashing I decided to base a transport device on a tadpole recumbent design. I had a look at what others had done and set about drawing up a specification. I didn’t want this to be a replacement for a car, or a bicycle but something to bridge the gap, for people who lived a little too fare from the office to take their bike but close enough to feel guilty about picking up their keys for the trip.

We selected GM as a possible suppler for the drive train, with the idea to keep the engineering required to power the vehicle to a minimum. I talked over email to Fiona at GM before placing our first order for samples but unfortunately when the package arrived and was unpacked we discovered that they had been some miscommunication and the wrong motor had been sent. we kept this motor and again ordered and paid for the Magic Pie kit we had previously requested.


We’ve built a frame to test the performance and will keep you up-to-date on how we are getting on.

[e-lmer]

Great looking build Chris.

I am curious to know how you are addressing the battery installation.

One issue you must address is keeping the packs from just
bouncing out when you hit a bump.  I suppose you could
take the socket from one of your tools so they clip in.

Off the shelf packs in a clip in configuration would be great for
replacement, but you would need some pre-start balancing
to get them be safely at the same voltage upon connection.

Once installed you have to choose between in-place charging or
removal for a charging array.

Finally, I would like to know which chemistry you are using
in your battery packs.

[CEL-UK]

It’s quite easy actually, I work for CEL, a power tool company that has a unique battery called the POWERhandle system (www.POWER8workshop.com), unlike some other brands the batteries slide on from the side and then latch, all the weight is carried by the retaining ribs not the latch. I've ripped some mating parts our of older products and mounted them behind the seat. Each battery pack has 10 Li-ion cells in(5s2p), creating between 18-20volts, so I've made a loom to have 3s2p, it should give me around a 20mile range with a good top speed. All the packs have a PCB to control balance and over discharge, the packs in parallel naturally balance and the sets in series only give up their power with their own capability.