Battery Capacity (Ah) Requirements

[Mustapha]

Hi, I'm currently pricing components to convert my mountain bike to electric for commuting. I haven't picked the controller yet but I plan on using the Crystalyte 408 at 36V. I'm not worried about it's low end performance as I plan to pedal before throttling up the motor. I also don't really care about exceeding 20 mph because my commute will be through stop-and-go city traffic and I'd rarely have enough time to get going faster anyways.

I weight just under 200 lbs and plan on commuting 6.5 miles to work and then back. There are two small hills (overpasses) on my route. I'd prefer to not need a charge when I get to to work. I would like to avoid SLA batteries and I've been told that for my intended range I'd need about 12Ah if I went that way. What capacity batteries would I need if I used NiCd, NiMH, or a Lithium variant? Can you recommend a site with good battery prices? ebikes.ca seems to be all sold out.

I'm also curious, if I did go with the more powerful 5300 series Crystalyte motor, how much would that change my battery requirements?

[Mr York]

Batteries are rated in Ah, so if you need 12 Ah you would look for a battery or battery pack that supplies 12 Ah regardless if it is sla, nimh, or nicad. An example would be a nimh battery pack that supplied 12 volts and 10 ah, put three of them in series to get 36 volts at 10 ah. Put the three in parallel to get 12 volts at 30 ah.

If you run 36 volts and a 10ah battery, you have 360 watt hours of power (watts = volts x amps). If you run your motor at 360 watts, you could expect about an hour of power if you treated the motor well, less if you hot dog and accelerate quickly. The more watts you use, the less time you will have on the battery pack.