Confusion regarding voltage

[Pasley69]

Hi,
I am confused about a Bafang H405 motor I am considering for my touring bike. The description says "36v 250w, 48v 350w".
Does that mean there are two different models? or can it use either voltage? and if so do I have to change anything if I swap between batteries.
I assume there will be a setting change in the handlebar display unit - anything else?

Can't seem to find a definitive answer in the product brochures or on the Bafang website.
Reason I ask is that my group carries a spare battery in case someone's battery goes flat on long trips. Do I need to make sure the voltage
is the same. Haven't had to address the issue before.
Thanks
Adrian

 

[scrambler]

It is about what controller is being used.
The controller will dictate and set the parameters for 36V or 48V.

Not sure which controller are used with that motor and whether some can handle both configuration.
But the battery being used would definitely have to match what voltage the controller can support.

 

[Pasley69]

Thanks, so I guess I can change to a different voltage battery and then
go into the controller mid-tour and change the voltage if necessary.
Cheers
Adrian

 

[scrambler]

If the controller allows it.
Some controller may not.
If it is a 36V controller than cannot take 48V, using a 48V battery may blow it up.
If the system is setup for 48V and you put a 36V battery you most likely just lose performance

 

[Pasley69]

I am interested because I use a 36v TSDZ2b and I know this can do 48v. But you need to reprogram it either by hacking the original firmware or installing the OSF version.
But also the 36v and the 48v motors are wound differently - so go one way and you lose performance, go the other and if you don't blow things up you'll need a higher
cadence and deal with more torque.

 

[Gionnirocket]

Where are you reading the voltage description?
On the motor? Controller? Or the Bafang website?
Your motor's voltage rating should be printed on it.

If you are only reading it on the Bafang website... It's two different motors.
Take a look at the punctuation.
Comma denotes a different motor.
If it were a range in the same motor it would be written with a hyphen or a forward_slash ... Like the sproket size and speed limit.