More battery and/or more power


I recently bought a RadWagon from Rad Power Bikes. It has a 750w peak motor, and a 48v, 11.5 ah battery. I'm using the bike to commute to work, 22 miles each way. I recharge the battery at work and at home.

I'm a heavy rider, weight more than 2 Courts (this should be a new standard of weight measurement, no? :)). The battery barely gets me to work at pedal assist level 1 (lowest), with almost no throttle used. My route is fairly flat. On PA1, my speed varies between 14mph and 19mph depending on the grade.

I'd like to be able to use PA3 or more for most of the trip to increase average speed, but the battery would die before I got there. The ways I see to be able to do this (besides the obvious one of get in better shape!) are:
  • Get a 1000+ watt motor
  • Get a higher capacity battery
  • Carry an extra battery
Any suggestions on which of those options would be best/cheapest? Any other suggestions I missed?


New Member
It is about how efficient your motor is, how Good your battery cells are and what is amphours of battery in reality
Carrying double battery OR carry 1 double ah battery is simply same thing so do not go for double battery

George S.

Well-Known Member
20 miles at a very moderate speed with a low level of pedal assist? The weight is a factor to get the bike moving, but once it is up to speed, not so much.

I'd pick up a cheap amp hour meter and see what the real capacity of the battery is. Sounds like about 200 watt hours, not the 550 it should be.

This one includes a shunt, which is easier for some installations:,160_&refRID=0Z1G3C9Q66WQ5QEZZ923
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Well-Known Member

You have a new bike that is under warranty. Call Rad Power Bikes (800) 939-0310.

22 miles or so is a poor range with that size battery at minimal assist level. something is wrong.

Doesn't look like a larger battery would fit in that frame, and carrying a second battery seems like a hassle if you to change it out mid trip.
How much more than two Courts? A gallon?:) Weight does effect range, however yours does sound short for a 48v 11.5ah battery. Make sure your tires are pumped up to highest capacity..can make quite a difference.


Thanks for the replies. I do check the tire pressure for each ride for exactly that reason, and I agree it seems like a short range. They claim the battery can go 15-40 miles, but I had thought 15 miles would be the range if you used 100% throttle. I had heard from one of the founders they went 40-ish miles on PA1, but she's about 1/3 of my weight. Even so, I was hoping to get a comfortable 25mi out of it on PA1. I mentioned it to them and they didn't seem to think it was all that surprising. While I do have confidence that their setup is working as it should be, and the battery seems to be high quality, I'll check out the amp hour meter and go from there. I suspect though that I may have a 2nd battery in my future...maybe it will be a good excuse to get the wife a bike so I can steal her battery for commuting :).


What is the bikes top speed ?
I ask because your low average of 14MPH in ass. level 1 seems high, and maybe using up power faster than expected.
Have you checked you voltage at end of your 22 miles ? You said "barely gets me to work" so I'm thinking there may be more left than you think. Just some thoughts.

Also wind resistance is a pretty big factor, your weight, and a fairly heavy bike, may well be using up say 400wh, or about 80% of your battery.

At least you got lots of places to pack on an extra battery.


Top speed is 40 kilometers per hour, or about 24mph, but I haven't had it above 22mph...can't pedal hard enough. No, haven't checked voltage. I know it's barely getting me there, because one trip I varied the route and had a short/steep hill at the end, and it died on the hill. So now I stick with the flatter but slightly longer route, and it gets me there, after having been on 1 bar for about 4 miles.

Current battery is a dolphin pack 48v 11.6ah, and I'm thinking Luna Cycle's 52v 13.5ah dolphin pack should work on the bike, and should give me a little more power/range to boot.