- Thread starter Roseville
- Start date

Example:

1) You get the watt hours by multiplying the amp-hour spec of a battery by its voltage. So a 48V 10.5 AH battery is 502 watt-hours.

2)You take a typical number for watt-hr/mile. 20 watt-hr/mile is common, although my 250W hub motor bike only uses 8 watt-hr/mile at 12-14 mph with me pedaling a lot. However, my mid drive bike does use 20.5 watt-hr/mile at 20 mph.

3) You knock off 10% because the amp-hour rating on a battery figures you run the cells all the way down to minimum. In practice, battery makers shut them off with at least 10% margin. Also knock off another 10% if the battery is a year old.

I actually have that 48V 10.5 AH battery. Figure 400 watt-hr. Yeah, I might get 40 miles out of my little motor. I have done 28 miles and still looked like it was half used up. But I'm only going 12-14 mph.

I use it mostly to commute to work around 13 miles round trip, 4900-5400 ft elevation range, I'm about 270 lbs, and the bike+gear around 75-80 lbs. I have it on the highest PAS (level 5, 20 mph max) and use most of my wattage in the afternoon since it is 70% uphill. I try to pedal as much/hard/fast as I can to keep the power around 150-300 watts. The combo of the extra weight and steady 4 mile incline zap about 10-15% of my range at the highest PAS level. I might only be at a 1-5% loss if I drop the PAS to 2-3; but, I don't want to spend more time in traffic at a slower pace just to save 1-2 cents of power.

I did take the RadRover on a endurance run last weekend (PAS level 3, 12-14 mph, power levels 50-150 watts of assisted power, flat terrain). I was able to go 36 miles in 3 hours before my legs just got too tired. I still had one solid bar left (blinking bar means almost depleted). I think I could have broken the 40-45 mile mark on level ground (last 4 miles was the 500 ft elevation climb uphill to my house).

The max has been about 35 miles using tour with about 3,500ft of elevation gain.

This range is consistant between both bikes and both batteries, I weigh 75kg, am pretty fit, and 95% of my riding time is spent off road.

*Battery swapped to complete the last 1.4 miles.