Recommend a battery.

stevetedesco

100 µW
Joined
Mar 2, 2021
Messages
9
Hello
I am trying to decide what type and size Li-ion battery pack to run ...

TWO 800watt 48volt hub motors each
w/30amp controllers.
What ah battery could run for 2-4 hrs around 20mph???

Thanks
Steve
 
To do 80mi @ 19mph with two motors on a upright bike (no tuck) on flat ground with no head wind on a nice day without stopping and starting, just a straight ride a 48V 35ah or two 17.5ah should be close.
 
Thank you!
Do you what it means when the put 1000w on the battery. Is max motor it can handle?
Does it mean I need one that says 1600w?
 
The watt label on a motor does not have any thing to do with a battery's advertised watts.

Most motors can handle more watts than advertised. It's really about heat. You want a motor that can do what you need it to with out getting to hot. 800w motor should take 800w all day long. Not to say that it should take 1200w for a few mins at a time. Depends on the motor.

Battery's should deliver all the amps you need with out stressing the battery. A battery's Watts is how many watts stored in the battery but you can not used them all without shorting the battery's life. I never plan on using more that 70% of my battery's watts.

Its best if you read up from the experts here on ES. Good information about motors and maybe the motor your planning on using.
Batteries there is a lot to read about batteries. Don't confuse Ah with amps going to your controller.

If you try to go to fast and far it will be more like a motorcycle not a bike. Fast is not to hard, just like distance but not both at the same time.
 
Good advice here. Another point to make is that battery cell types also make a difference. As an example a pack made of Samsung Q cells will be able to deliver higher amps but the overall capacity in WH will be less than a similarly configured pack made of GA cells that can't flow as high a current. But if your motor can't pull the high amps that the Q cells deliver then the GA cell pack is a better alternative for more range. Q and GA are examples but there are other similar cells.

ZeroEm said:
The watt label on a motor does not have any thing to do with a battery's advertised watts.

Most motors can handle more watts than advertised. It's really about heat. You want a motor that can do what you need it to with out getting to hot. 800w motor should take 800w all day long. Not to say that it should take 1200w for a few mins at a time. Depends on the motor.

Battery's should deliver all the amps you need with out stressing the battery. A battery's Watts is how many watts stored in the battery but you can not used them all without shorting the battery's life. I never plan on using more that 70% of my battery's watts.

Its best if you read up from the experts here on ES. Good information about motors and maybe the motor your planning on using.
Batteries there is a lot to read about batteries. Don't confuse Ah with amps going to your controller.

If you try to go to fast and far it will be more like a motorcycle not a bike. Fast is not to hard, just like distance but not both at the same time.
 
Thank you!

Don't understand why I get such a wide range of input 10 ah -100 ah.
Its way more complicated than I ever thought!
Wish I could find someone in US that can make what I want.
Steve
 
4 hours at 20mph is 80 miles, 135km

If you put in 50% leg work you need a 20 AH 14S batery / a 60V one. If you want to ride all the way, you need a 35-40AH 14s / 30AH 35AH 60V.

On a very efficient bike, 18 Watt Hours will get you 1 km, that's about 1.5 3500mah 18650 cells per km.
 
I know using ah is better description for stored energy. Badly use watts because never know how many Volts we are talking about.

I have a 24ah battery how far can I go. Sort a incomplete is it not?

by Elektrosherpa » Aug 18 2021 3:46pm

ZeroEm wrote: ↑Aug 09 2021 1:32pm
A battery's Watts is how many watts stored in the battery but you can not used them all without shorting the battery's life. I never plan on using more that 70% of my battery's watts.
Stored are not "Watts" but "Watt hours"...
 
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