electric bicycle milage per charge

paul

paul

Well-Known Member
this is almost to simple and i cannot believe i only realized it now. those of you that have different battery's tell me if you get the same results. i have a 10ah battery and a 15ah battery. so theoretically the 15ah battery should get 50% more range then the 10ah battery but it does not. it gets around 30% more. conclusion is rather then get a 20ah electric bicycle battery i would be off having 2 10ah battery's stacked and just unplug one and plug in the other when one goes dead. i would really like input on this, it just hit me today while i was looking at 20ah battery's.
advantages of 2 battery's would be
1. better range
2. short trips only mount one battery and make the bike lighter
 
I have a 20ah LifePo4 and a 15ah NiCoMn. The 20ah battery is twice as heavy and big and gets an average of 34 miles while the 15ah gets <24 miles. (Both averages are on flat land) I usually load both battery's on my rack but I can notice a handling difference when I bring only one battery.
The one thing I notice is my 20ah battery has more punch and power. Also the green light on the throttle stays on (even at full throttle) for 30+ miles and the 15ah battery will start to fade after 5 miles on full throttle but will come back on when I reach top speed.
Personally, I prefer using my bigger battery because of the range and use the 15ah one as a back up.
 
sometimes the lower mah battery doesnt have the "C" abilty of the larger battery....so giving the bike a better battery would allow the motor to pull its full or more amperage from the battery......draining it quicker.
 
Both my batteries are C rate. I think the important thing to look for in a battery is the discharge rate. I made the mistake of buying a 15 amp continuous discharge rate and the battery only gets a maximum of 14 miles. Here's the link to my 15ah battery.
http://www.bmsbattery.com/48v/609-48v-15ah-lithium-ion-alloy-shell-ebike-battery-pack.html

The only thing I don't like about the NiCoMn battery is you can only get around 800 charges unlike the LifePo4's 2000 charges.
 
I'm still trying to understand this battery language. Could someone please explain the difference between 2 hypothetical battery's? All I understand right now is they're both 5 amp.

5000 mAh 4S 25-50C
5000 mAh 4S 35-70C
 
biknut said:
I'm still trying to understand this battery language. Could someone please explain the difference between 2 hypothetical battery's? All I understand right now is they're both 5 amp.

5000 mAh 4S 25-50C
5000 mAh 4S 35-70C
Click to expand...

First term is 5000 mah or 5ah. Can discharge at 5 amps for 1 hour.

Second term is 4S or 5S, that means 4 cells or 5 cells are connected in series.

The third term is mostly used as a marketing term that most likely is just a number that is printed on the side of a rc lipo pack.

1C max discharge rating means you can max discharge the 5 ah pack for 1 hour.
2C max discharge rating means you can max discharge the 5 ah pack for 1/2 hour.

The higher the C rating the faster you can discharge the cell without damaging the cell.

Discharging at 50C would make for a very short ebike ride. :)
 
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motortriker said:
1C discharge means you discharge the 5 ah pack at 5 amps for 1 hour.
2C discharge means you discharge the 5 ah pack at 10 amps for 1/2 hour.

The higher the C rating the faster you can discharge the cell without damaging the cell.

Discharging at 50C would make for a very short ebike ride. :)
Click to expand...

Thanks, the C rating was what I am the most fuzzy on. So I guess a higher C rating allows faster charging too?
 
Yes. The higher the C rating the faster you can move the power in and out of the cell without causing damage.
 
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Easy Rider said:
Both my batteries are C rate. I think the important thing to look for in a battery is the discharge rate. I made the mistake of buying a 15 amp continuous discharge rate and the battery only gets a maximum of 14 miles. Here's the link to my 15ah battery.
http://www.bmsbattery.com/48v/609-48v-15ah-lithium-ion-alloy-shell-ebike-battery-pack.html

The only thing I don't like about the NiCoMn battery is you can only get around 800 charges unlike the LifePo4's 2000 charges.
Click to expand...

The link only says High C rate, but not exactly what the actual rate is.

When people ask me what my range is I answer, that's a trick question. It depends what speed we're talking about. For my 18 ah battery I could be telling the truth if I said 80 miles, or 17 miles. At top speed it eats a little over 1 ah per mile, so your 14 miles from 15 ah sounds the same as my bike.

If I cruise at 20 mph I could go about 50 miles on 18 ah which is the factory claim for my bike.
 
The battery he linked to says,

Maximal Continuous Discharge C-Rate: 30Amps.
Capacity: 15Ah.

It would be rated at 2C Max Continuous Discharge.

Fully charged to discharged in 1/2 hour is about the fastest it should be discharged.
 
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Regardless if I'm going 10 or 25 mph. My bike has been pretty consistent with the mileage. Every weekend I use the app on my phone and the mileage for each battery is always within + or - 1 mile from what I'm expecting the mileage should be and that's running that battery all the way down until the battery shuts down. I have logged & recorded twenty five 40+ mile road trips so all my data is from my personal experiences.
 

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wow it must be flat where you live. that is awesome easy rider. I am gonna down load that ap
 
paul said:
wow it must be flat where you live. that is awesome easy rider. I am gonna down load that ap
Click to expand...

Yeah it's pretty flat but this weekend we're riding in the hills. The app is B.icycle
This app will be good for you because it also shows "climbed altitude" as well as "current altitude".
I got the app because i want to make sure how many miles I've traveled per charge. The last thing I want to do is pedal my bike for miles with my bad knees.
 
Easy Rider said:
Regardless if I'm going 10 or 25 mph. My bike has been pretty consistent with the mileage. Every weekend I use the app on my phone and the mileage for each battery is always within + or - 1 mile from what I'm expecting the mileage should be and that's running that battery all the way down until the battery shuts down. I have logged & recorded twenty five 40+ mile road trips so all my data is from my personal experiences.
Click to expand...

I see what you're saying. Averaging your best and worse mileage both come out to about an average speed of 15 mph.

I don't understand how that can be. Shouldn't you always go the same distance at the same speed?
 
biknut said:
I see what you're saying. Averaging your best and worse mileage both come out to about an average speed of 15 mph.

I don't understand how that can be. Shouldn't you always go the same distance at the same speed?
Click to expand...

I vary my speeds between 15-25 mph. There are times when I'll go 15mph for 10 miles and that still won't affect my mileage. I know what you mean by my mileage should increase but it really doesn't.
Just remember Biknut, I don't have a bike like yours that can go 50 mph...I just wish I did! :)
 
I sometimes wish I can but my riding buddy has a Prodeco that will go a little over 20 mph. I'm not complaining because its cool cruising all over the Bay Area with him. We've already rode 1068 miles.
 
My stock battery is 18 ah 72v. If I were to buy a 10 ah 72v battery to carry on my rear rack, could I simply parallel it to my stock battery to have 28 total ah?

I expect I would unhook the battery's for charging, and probably use 2 separate chargers.

Yes, or no, or not that simple?
 
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