Battery Vehicle Society

Been building another toy (winter has to be good for something). It uses a 250W Unite MY1018Z geared motor and 4qd controller combined with 36 volts worth of Ian Goodman's LifeBatt cells.
The only bits I had to make were the motor mount and chainring adapter.
The cranks are special trials cranks with a threaded section on the right-hand crank that accepts a standard freewheel. Both chainrings are then bolted to this freewheel. The motor sprocket also runs on a one-way needle bearing. This means that you can use the motor and pedals independently or at the same time. Makes you feel like superman Just pedal along at a gentle pace and feed in as much additional power as you want. It also means that all the motor power goes through the standard derailleur and gears, which is great for hillclimbing. The motor and mount weigh about 6lbs, but because they're in the centre of the bike they don't affect the feel of the bike too much, so when you ride it without the battery pack it still feels pretty nimble. The only real drawbacks are that the motor is quite noisy, so it's not quite as stealthy as I'd like, and the extra torque can cause the chain to skip unless it's set up just right. Otherwise it's great fun. Roll on the warm weather!

Hay Mal that rocks, nice job, did you use cell balancers in the end

Looks a really neat job,

what is the speck of the controller?

Very very nice! I'm impressed

Would you like to write something for Plugged In about this?

Ta Tes. Yes, I'm using the LifeBatt VMS as well. Lots of flashing lights so it must be good . I'd guess from the way the little red LEDs flash that the VMS is shuttling current around during charging. I've run half a dozen partial charges so far and the individual cell voltages are all within 0.04V of each other after charging, which is good. The charger simply shuts off when the pack voltage reaches 43.8V (3.65V per cell). At the moment the low voltage signal just triggers a piezo buzzer, but Ian's promised me a switch module that will actively cut power to the controller as soon as Taiwan have finished building it.

The controller is a 4qd Porter 48V 40A, so plenty of headroom there.

Thanks Kelvin. Yes I can write a bit for the mag. You want it in Word don't you? I guess that'll be next issue though, so no hurry eh? I've got a stack of neglected chores to catch up on...

MalcolmB wrote:Thanks Kelvin. Yes I can write a bit for the mag. You want it in Word don't you? I guess that'll be next issue though, so no hurry eh? I've got a stack of neglected chores to catch up on...

Noooooo!!!!! simple straight forward .txt file please as Word puts in unusable mark up which means you waste time trying to get a pretty all styled document which can't be used and I then have to try to replicate.


Just send me the straight text and the photos

Hopefully the mag will be out in the post in a fortnight

No problem at all to create a text file, but I'm just curious why Word should be such a problem. It's the main tool I use for work and it's how I receive and deliver most of my agency jobs (language translations). I know excessive formatting can be a problem, but if you write simply without adding tabs or font formatting etc then Word files should be readily transferrable into most editing/layout software, shouldn't they?

That looks really good -- well done that man

What do you think of the 4QD controller ? Read a lot about them but have never personally tried one.

Very nice work Malc, that looks great:)

Cheers Steve! I reckon I'll do a lot more miles on this than I will on my motorbike this year. At least that is if I can resist the almost irresistible temptation to tear it apart and start building another one, stronger, better, faster... Maybe I'll just lean the bike up against my motorbike, turn the garage lights down low and leave them alone for a bit...

...hrmmm, oh yes, the 4qd controller – it does what it's supposed to do without any fuss. It's pretty basic really, and I probably could have done the same job with a much cheaper Chinese version, but I've learned a lot from scouring the 4qd site and I wanted to give a little back

Wow! Another work of art. Nice one, Malcolm.

Hope you're feeling better after the weekend. We were sorry to miss you.