## amp hour v/s volts

General Discussion about electric vehicles.

### amp hour v/s volts

I admit I don't know all that much about technical electrical things so I am posing this question for you more attune individuals!! Right now I run a 48 volt gohub with 9amp hour batteries,my question is could I run 24 volts on this system with 14 amp hour batteries and increase my distance and just have less power/speed?? Or would I need a different controller or would I not be correct at all regarding the speed/power vs distance with the increase amp hour batteries ??
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jimmyg4life
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As long as the low voltage cutout on your speed controller will work with 24v, you will get longer run times with less power. If you're looking for the longest range, generally going slower will help, but only to a point.
Lowell
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it won't help you any to go to the 24 volt system, except to force you to not go to full speed.

24volts and 14 amps = 336 watt hours.
48volts and 9 amps = 432 watt hours.

So your 48 volt system has the potential for longer range by almost 30%

Drunkskunk
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Drunkskunk wrote:it won't help you any to go to the 24 volt system, except to force you to not go to full speed.

24volts and 14 amps = 336 watt hours.
48volts and 9 amps = 432 watt hours.

So your 48 volt system has the potential for longer range by almost 30%

Oops, didn't read closely enough. For some reason I was thinking he would switch to a 2s2p configuration to go to 24v.
Less watt hours is definitely not a good thing, but the lower power consumption might offset it enough. Test it out and check your Wh/km figures at different speeds.
Lowell
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24v would be kinda like riding at 50% throttle...

Ride around at half throttle and see if your bike will make it up the hills, see if you can tolerate half the torque and slower overall performance;
see how much further you can travel.

Try that and tell us how it went.

Have a Nice Day,

TD

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TylerDurden
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Running at half throttle should be pretty close to running with a lower battery voltage. You could install a resistor in the throttle to limit the output. The resistor could be on a switch so you could have a high and low setting.
"One test is worth a thousand opinions"

fechter
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I used Fechter's adjustable current mod on my speed control and installed an external pot that I can adjust while riding.
Lowell
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24v on a brushless hub motor will not be very much fun... they only fizzle at 36v..

Changing over to NIMH instead of SLA would improve range.. for the same 8ah-nimh vs 9ah-SLA you will get a good 20% more distance per charge !!
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Ypedal
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I have the gohub too. I think the controller will cut off at 24v. The system seems to operate most efficiently at 36v so if you can somehow configure your batteries back to 36v, this should give you the best range.

You can have good range at 48v if you can keep your top speed down to below 12 mph and peddle a fair amount.

For reference, I have the milwaukee battery pack for my gohub. Using 4 packs in 2s2p (54v@ 6ah) and full throttle, i get about 9 miles range. Using 6 packs in 2s3p (54v@ 9ah) and cruising around 20 mph, i get about 20 miles range.

What kind of range do you need?

jondoh
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