• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Electric wheel chair, question about amps

Status
Not open for further replies.

joshua17ss2

New Member
i got an electric wheel chair, and ive been working on modifying it, i think that the original motor control is totally dead, so im working on desinging my own.

The motors are 24 volt DC motors. their are 2 12 volt 50 amp batteries.

my question is do the motors actually run on the 50 amps, or is that more for longer battery life ? Maybe only uses 50 when loaded down with a person, or something like that.

i want to find 24 volt 50 amp RC ESC w/ reverse but my time spend on google has given me few results.
i would also like to know if either there are ESC that would meet my needs, or if i could use a much lower amp ones.
any information would be appreciated.
 

Sceadwian

Banned
There is no such thing as a 50 amp battery.
50 amp hour maybe, it has nothing to do with the motor itself though. 50AH's means it will provide the equivalent of 50 amps for 1 hour. BUT amp hour ratings on lead acid batteries (what you're using) are based on a 20 hour discharge. So you can only draw 2.5 amps off that battery and still get a 50AH rateing on the battery. More than 2.5 amps at a time, and the capacity is lower from internal losses. You need to determine what the TRUE current draw under a typical load is going to be for your motor before you can determine what kind of ESC you're going to use.
 

Willbe

New Member
i got an electric wheel chair, and ive been working on modifying it, i think that the original motor control is totally dead, so im working on desinging my own.

The motors are 24 volt DC motors. their are 2 12 volt 50 amp batteries.

my question is do the motors actually run on the 50 amps, or is that more for longer battery life ? Maybe only uses 50 when loaded down with a person, or something like that.

i want to find 24 volt 50 amp RC ESC w/ reverse but my time spend on google has given me few results.
i would also like to know if either there are ESC that would meet my needs, or if i could use a much lower amp ones.
any information would be appreciated.
The Web tells me 5 hours of W/C operation between charges is reasonable so this would put motor current draw at ~10A.

To measure max current I'd load the chair with 300# and go up a wheelchair access ramp; these ramps are designed so that most or all W/Cs can go up it.

The reliability of your control circuit must be very high because a life depends on it.

If the rated motor current is I and you use PWM for the motor control, exceeding 5I will probably demagnetize the motors.
 
Last edited:

Nigel Goodwin

Super Moderator
Most Helpful Member
You can't really specify the load requirement for a motor, because it varies massively over it's range of use - but consider a much smaller, far less powerful, motor in an R/C car can easily take over 100A on peaks, and needs a substantial ESC.

For reliabilty reasons alone I would suggest you replace the controller with the correct type, unless you're just ripping the motors out to make a robot wars type machine?.
 

joshua17ss2

New Member
Robot type war machine is about how i would describe it. im shooting more for simple Robotic base.
i still have the original motor controller, and im still trying to bring it back to life, im waiting on a new hex inverter chip as i think due to a wiring mishap it got burnt up.
so im gonna replace it, and try again, i already bypassed the brakes on the motors, so they now turn off when the power is applied for now. i just want to get the wheels turning again.

At the moment i just want to get the whole base responding to an RC remote. then move on to a computer.
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top