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Peak Power - how to calculate
#1
I am confused how to calculate by bike components, peak power.

The battery is 48v 15a. That is not what I am looking for (48x15 =720 )
That is not the peak power . My bike is advertising 1800 w peak power.
The Controller
Bru shiess DC Motor Controller ( I am typing it out as it is written , what a joke huh?)
Voltage :48v | Low Voltage protection: 40 +- 0.5V
Maximum current :25+-1A |

I thought 48v times the max current of 25 = 1200 would be peak watts no?
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#2
@brushless it may be a reference to the start up amperage which will be much higher than the morors rated Amps so that might be how that value was derived. Or it could be related to the mechanical power of the bike not electrical. Not sure how that would play out in calculating the "peak power", but I think you need to know rpms and torque values.

I would contact the seller/dealer (doubt they'd know), or better yet the manufacturer and request their means of calculating their own advertised power value.
Ride Fast, Be Safe!
Howard
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#3
Thank you for the reply...
image for 1800 peak watts

This is what I want to calculate. I want to see if it is even possible with the components it has, As I mentioned above about 25A controller.
The motor is '' 1000w '' but sticker on bike shows 750w.
So 48v battery 15ah.
1000w motor or 750w motor

I know there is a way to calculate it, I believe it IS 48v (battery) X 25A max current controller, but that is 1200w, Not 1800w. I honestly believe they are lying.
25A max current controller
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#4
Update, This You'Tube vdeo explains it.
"Overview & Ride Out! 750W 48V Folding Full Suspension eBike Review & Test Ride Jasion Hunter Pro"
The battery on the bike is 48v 15ah. The motor controller located behind the main battery connection plate.
48v battery = When fully charged, it should read 54.6 v.
The max current on the motor controller shows 25A + - 1.
54.6v x (max current on the motor controller 25A+-1) 26= 1419.6W
54.6v x 26A = 1419.6W

Therefore there is no way 1800w is legit.
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#5
I'm not into assisted pedal bikes but I think I can offer a very good answer to what they are trying to suggest here judging from the marketing materials you shared, normal bikes nowadays can have power meters installed which measures the amount of watts you generate like the actual down force you exert to push the pedal down, 1800watts is pretty high and is actually the amount of power you need to go up a steep climb if you are a heavy rider, that's why they promote this as such because E-bikes will need more power to go thru climbs due to the weight of the battery and the motor, 1800watts advertised should be in theory enough to help you conquer the climb. what do you guys think?
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#6
(07-20-2025, 12:39 PM)brushless Wrote:  Thank you for the reply...
image for 1800 peak watts

This is what I want to calculate. I want to see if it is even possible with the components it has, As I mentioned above about 25A controller.
The motor is '' 1000w '' but sticker on bike shows 750w.
So 48v battery 15ah.
1000w motor or 750w motor

I know there is a way to calculate it, I believe it IS 48v (battery) X 25A max current controller, but that is 1200w, Not 1800w. I honestly believe they are lying.
25A max current controller

So 48v battery converts to 54.6v on full charge. 54.6 x 25 Amp a bit over 1200w. Do they think we will not check? I guess so.

(08-06-2025, 10:54 AM)meamoantonio Wrote:  I'm not into assisted pedal bikes but I think I can offer a very good answer to what they are trying to suggest here judging from the marketing materials you shared, normal bikes nowadays can have power meters installed which measures the amount of watts you generate like the actual down force you exert to push the pedal down, 1800watts is pretty high and is actually the amount of power you need to go up a steep climb if you are a heavy rider, that's why they promote this as such because E-bikes will need more power to go thru climbs due to the weight of the battery and the motor, 1800watts advertised should be in theory enough to help you conquer the climb. what do you guys think?

1800w "in theory", is not how I shop. That's false advertising, no lying, or Chinese math. I hope your not suggesting a human needs to produce 1800w to get up a hill!
Here's the math. So 48v battery converts to 54.6v on full charge. 54.6 x 25 Amp a bit over 1200w, not 1800. Do they think we will not check? I guess so.
Two Wheels
Stay Safe
Robert
"SPINMAN"
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