At what wattage can 1200 wh of battery give me 60 mile range

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boytitan

100 W
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Jan 7, 2017
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Location
Buffalo Newyork
Wonder if its possible. I have a DD hub motor with a 26 amp controller but the display lets me adjust the max wattage. I was wondering if I limit wattage to 500 watts can that give me 60 mile range. Also add in heavy pedaling with 42t,11t gearing.
 
Not sure you can or should use all 1200 Wh of your 1200 Wh battery... but using that number:

1200 wh / 60 mile range = 20 wh / mi. Seems doable.

500 watts / 20 wh / mi = 25mph. You need to keep you speed at 25 mph
to achieve that range at 500 W continuous draw.

400 watts / 20 wh / mi = 20mph. This might be a more realistic speed.

I ignoring (or ingorant of) lots of factors, so take the above with a grain of salt.

It gotta be worth experimenting! Good luck
 
That's about the size of my battery. I think you could barely get that range at around 20mph with moderate pedaling but you'd be completely discharged at the end.
 
I believe you should have a much bigger battery for this target range. You are playing with ideal numbers in terms of effective battery capacity, system efficiency, and riding conditions. A dirty cold windy day, and all numbers fly.
 
At 20MPH your tire choice is going to make a pretty big difference on your range. 2.5" fat knobbies, probably not gonna get 60 miles. 1.25" high pressure road tires, should be pretty easy as long as your motor is reasonably efficient at that speed. On my touring bike with a BBS02 and 32C tires at 85PSI, I use around 12Wh per km, so around 20Wh/mile. Cruising speed is 23 mph, but the motor is spinning at near full speed for max efficiency. Not sure how a hub motor running well under full speed will do in terms of efficiency.
 
It depends on many things. Are there hills where you ride? How efficient a bike are you riding? My mid-drive recumbent bike has a 12s, 39 volt average, 30 Ah Ping pack. I pull 80%, 24 Ah, out of the pack, 39 x 24 = 936 Wh. A few days ago, I took it easy and rode at 17.0 mph average, and pulled 12.4 Wh/mile for 75 miles The next day I rode at 20.2 mph average in the wind, and pulled 15.9 Wh/mi for 58.5 miles. Five years ago, when I was younger and in better shape, and the battery had less voltage sag, I did 80.7 miles at 21.1 mph and 10.1 Wh/mi!
 
This is a 1 time thing for the upcoming friday and we are talking pedaling as hard as I possibly can I have done 30 mile trips on a regular bike before.
 
a few considerations--

--if you ahve a lot of stops and starts, it's going to seriously impact your range, and could potentially halve it depending if they are frequent, like every 1/4 mile or 1/8 mile, like in city traffic, depending on your motor's usage from a stop.


--as the pack ages, it will provide less wh, so to get the same range you'll need to go slower, or otherwise use less power. probably not a worry since it's a one time trip


--for range calculations, you should assume the motor does all the work, and then anything you get from pedalling is a good range bonus. ;) unless you already know how much power you yourself can provide by pedalling, and how much range at what speed you'd get by pedalling alone--in that case you could assume you'll get 25 percent of that power, because people generally pedal a whole lot less than they think they do when they are getting an assist from the motor. ;)
 
I will give my real world numbers of my DD motor and maybe it can help you.

I ride a mountain bike in a city with lots of stops and starts, afternoon headwinds depending on direction, not much peddling and average about 27 watts per mile and about 12 mph by the time I am able to get through the city. So for me to go 60 miles around my city I would need a battery of about 1620WH. Since I roll at 36v that would be about a 45Ah battery. (1620w / 36v = 45ah)........

or.....

I could use less watts. So if I set my bike (throttle or controller) to only allow me to use 1/3 of 27 watts which would limit me to about 8mph wot on the flats before stop and go city driving, but it would extend my range so that a 15ah battery could cover it. It would just take 3 times longer to get there. (for me that is 15ah x 36v = 540Wh) (depending on stop lights and other reasons to stop.)

So 60 miles on a 15ah battery is possible if you go slow. Any peddling you do is a bonus.

Your 1200 wh battery should take you 44 miles on it's own, limit your controller to say 18 amps and you should be able to do it with moderate peddling.

Just remember, as stated above, limiting you watt usage is only one part of a ton of variables....ike type of bike you are riding, weight you are pushing, terrain, wind, temperature, amount of stops and starts needed etc.

How many volts is your DD motor?

:D
 
e-beach said:
I will give my real world numbers of my DD motor and maybe it can help you.

I ride a mountain bike in a city with lots of stops and starts, afternoon headwinds depending on direction, not much peddling and average about 27 watts per mile and about 12 mph by the time I am able to get through the city. So for me to go 60 miles around my city I would need a battery of about 1620WH. Since I roll at 36v that would be about a 45Ah battery. (1620w / 36v = 45ah)........

or.....

I could use less watts. So if I set my bike (throttle or controller) to only allow me to use 1/3 of 27 watts which would limit me to about 8mph wot on the flats before stop and go city driving, but it would extend my range so that a 15ah battery could cover it. It would just take 3 times longer to get there. (for me that is 15ah x 36v = 540Wh) (depending on stop lights and other reasons to stop.)

So 60 miles on a 15ah battery is possible if you go slow. Any peddling you do is a bonus.

Your 1200 wh battery should take you 44 miles on it's own, limit your controller to say 18 amps and you should be able to do it with moderate peddling.

Just remember, as stated above, limiting you watt usage is only one part of a ton of variables....ike type of bike you are riding, weight you are pushing, terrain, wind, temperature, amount of stops and starts needed etc.

How many volts is your DD motor?

:D
Click to expand...

Its 48v DD. I was averaging just around 20-23 miles a charge on max throttle with half the watt hours at 1000 watts but this was with a 600 wh of battery. I am doing a controller upgrade and adding a second battery to get 1200wh.

I can't get accurate human input since red lights and wind kill my bike commutes on a regular bike. No matter where I go the average speed is 15 mph with spikes of 28mph. I tested this on various bikes with different gearing and the time is always around the same.
 
200-300 watts, should do that.

The best trick for maxing your range is to get a CA. With the CA you get a display of this rides average wh/mi. This accounts for the weather, your weight today, how much wind resistance your clothes create today, hills, starts and stops, and if you are pedaling hard today, or not. All the variables affect this days wh/mi average.

Watching that display, you get a clear indication if you are over or under the previously mentioned 20 wh/mi that will do the trick. If you just have a simple watt meter, you can of course still do mental calculations on the fly, and know where you stand. But for the long rides, its just worth it big time, to have the CA do it for you.

As you ride along, check the wh/mi every five miles or so. If you see it's 25 wh/mi, slow down, pedal more, till you get back to 20 wh/mi. If you get a surprise, like a head wind comes up, you will have to adjust, but you will know how much to slow down, for how long, to get there in the end on your 1200wh.

I have found this priceless on my longer rides, 60-80 miles. Very nice especially, if near the end of the ride you find you underused, and can zoom the last 10 miles after all.
 
1200/60= 20wh per mile. So a close guess would be you could ride at 19 mph on level ground without wind and get 60 miles.
http://www.ebikes.ca/tools/simulator.html
 
I read that, In ideal conditions, a road race cyclist lapping a race track at 25kmph uses 100w. Each extra 5 kmph needs another 100w.

Mostly u r battling the wind at over ~25kph.

u can extrapolate from that.

250w sounds fine for 30kph in theory.

I suspect hub motors suffer here. mid drives can operate at optimum efficiency rpm always.
 
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