Topic: 18v?

[giles]

Hi Guys,
Voltage question...
I understand that 24v would make the C5 faster (twice as fast minus the losses) but the plastic cog gearbox wont take it.

If you could choose a voltage between 12 and 24 (specifiying a LiION battery) where is the optimum for greater speed and not being too much for the plastic cog?  Would the risk of cog damaging power be reduced with a potentiometer allowing you to increase the volts, thus giving an accelerator of sorts?  I would guess this would reduce the shock load through the plastic gog, much like starting off with pedal power?

Sorry if this is a stupid question/idea.

Cheers, Giles

[techytype]

18 - 24volt?

i think the best you will get here is a well educated guess - but not from me 

i have a C5 with the earlier 24 volt conversion as yet not used it, been pondering the power issues.

having a twist grip 'throttle', imo the damage will mainly be done hitting full on throttle from a standing start or prolonged full power use.

in original format 12 volt use, you have a crude on/off speed control, so spurts are used to adjust speed which also allow the motor and gearbox to cool in between powered on cycles. that will also extend battery distances.

now  if we think about proportional electronic control, the motor will be run near constantly, even in periods where not under pressure and with a lot less 'off' cycles increasing heat and stress in both motor and gearbox.

so imo once you step away from the basic 12 volt format, voltage used is not the real issue, it is protecting the drive train from excessive 'abuse'.

to that end i've been playing around with designs to switch between 12 and 24 volt operation using heavy relays, but only allowed at above a certain speed, say 10 mph, perhaps with a time limited 'boost' for inclines.

regs
Alan