is it dangerous to run 17a controller witn20ah battery?

[alonstar]

hey,
is it a problem if ill run “48v 350W -17a current motor controller” with a 48v 20ah battery?
(motor is 48v- 350w)

thanks!

 

[harrisonpatm]

hey,
is it a problem if ill run “48v 350W -17a current motor controller” with a 48v 20ah battery?
(motor is 48v- 350w)

thanks!

17a motor controller means that the controller is capable of taking 17a of current from the battery safely. Likely it has its own current regulation.

20ah battery is a capacity measurement, not a current measurement. It means the battery is capable of delivering 20 amps for 1h, or 10 amps for 2 hours, or 5 amps for 4 hours...

You've gotten a controller and battery in the same voltage range, so there shouldn't be any issues there. A 350w motor running off a 48v battery means that it could be drawing 7 amps, likely more. 350/48=7.2, that's just an estimation, the controller could draw more or less from the battery, but you're still within spec. You should check your battery to make sure it can handle at least 10ish amps, but a 20ah battery is probably fine delivering that amperage.

Short answer is it'll be fine. Just explaining the math and the thinking.

 

[amberwolf]

Generally what he said above is correct, and the battery won't overpower the controller, if that is what you are worried about. (Notes are inline below)

17a motor controller means that the controller is capable of taking 17a of current from the battery safely. Likely it has its own current regulation.

Generally correct--but if it's got a current limit noted on it, it means it *does* have current limiting (regulation) of some form. Whether the 17A is a peak or a continuous limit is unknown, unless the controller label or manufacturer specs / manual / etc state one way or the other.

A 350w motor running off a 48v battery means that it could be drawing 7 amps, likely more. 350/48=7.2, that's just an estimation, the controller could draw more or less from the battery, but you're still within spec.

The wattage rating of the motor is not really relevant to the current draw the system may have. (that's just the amount of power the motor is designed to handle without damage to the motor, assuming that the rating is actually a real tested manufacturer rating, and not a marketing rating. Though the latter is much more common than actual tested capabilities, usually the motors can handle what they are claimed to under typical riding conditions).

The load placed on the motor, and the controller's current limit, will determine that instead.

So a 17A controller, assuming that's the max it can ever draw, will when sufficient load is placed on the motor draw that much current from the battery.

 

[alonstar]

17a motor controller means that the controller is capable of taking 17a of current from the battery safely. Likely it has its own current regulation.

20ah battery is a capacity measurement, not a current measurement. It means the battery is capable of delivering 20 amps for 1h, or 10 amps for 2 hours, or 5 amps for 4 hours...

You've gotten a controller and battery in the same voltage range, so there shouldn't be any issues there. A 350w motor running off a 48v battery means that it could be drawing 7 amps, likely more. 350/48=7.2, that's just an estimation, the controller could draw more or less from the battery, but you're still within spec. You should check your battery to make sure it can handle at least 10ish amps, but a 20ah battery is probably fine delivering that amperage.

Short answer is it'll be fine. Just explaining the math and the thinking.

thank you so much for ur reply. helped me a lot!!

 

[alonstar]

Generally what he said above is correct, and the battery won't overpower the controller, if that is what you are worried about. (Notes are inline below)




Generally correct--but if it's got a current limit noted on it, it means it *does* have current limiting (regulation) of some form. Whether the 17A is a peak or a continuous limit is unknown, unless the controller label or manufacturer specs / manual / etc state one way or the other.




The wattage rating of the motor is not really relevant to the current draw the system may have. (that's just the amount of power the motor is designed to handle without damage to the motor, assuming that the rating is actually a real tested manufacturer rating, and not a marketing rating. Though the latter is much more common than actual tested capabilities, usually the motors can handle what they are claimed to under typical riding conditions).

The load placed on the motor, and the controller's current limit, will determine that instead.

So a 17A controller, assuming that's the max it can ever draw, will when sufficient load is placed on the motor draw that much current from the battery.

Thanks for your reply!! gotta say i lost u somewhere there but maybe because im not a native english speaker so its a bit harder to understand the technical terms. still, much appreciated.

 

[AHicks]

The bottom line is you're fine running a 17 amp controller.