Powering multiple stepper motors with one 12V battery source

I’m making an Arduino robot with mecanum wheels. For this, every wheel needs its own stepper motor and own driver module. I’m using 4 NEMA 17 - 0.52N.m - 1.5A Stepper Motors and 4 A4988 Stepper Motor Drivers. The drivers need a voltage from 8-35V and a max current of 1A (2A at peaks).

To power this, I want to use an 8x AA battery holder, so I get a total of 12V. I’m pretty new to electronics, so my question is probably pretty simple: Can I use the same battery holder for all 4 Stepper Motor Drivers? Or will every Driver require its own battery holder to work correctly? Keep in mind that I’d like to be able to use the robot for a few hours before having to change the batteries.

You can certainly use the same power supply for all the motors. However I doubt very much that a battery pack with 8 x AA alkaline cells will be sufficient - I suspect it would discharge very quickly. Also, alkaline cells can't produce as much current as the rechargeable NiMh cells - but 8 NiMh cells would only give 9.6v.

Stepper motors are very inefficient and are not really suited to battery power. If you want a long run time then I think you would need higher capacity cells.

You have not said how big your robot is. I wonder if the small 5 volt 28BYJ-48 geared stepper motors would be sufficient?

...R

I've based myself on this tutorial, I also use his wheel design so this could give you an idea of the size: Arduino Mecanum Wheels Robot - HowToMechatronics
The biggest difference is that I want to make 4 modules, each one having one wheel, that you can puzzle together however you want. I also use a USB Host Shield to control the robot with a PS3 controller.

He uses a 3S Li-Po battery, but I have trouble finding one myself, which made me think about the battery pack.
Is there a simple alternative for a battery you can think of?

achillededoncker:
He uses a 3S Li-Po battery, but I have trouble finding one myself, which made me think about the battery pack.
Is there a simple alternative for a battery you can think of?

I don't know of any.

If you get a LiPo battery be sure to get a safe LiPo charger as well.

...R

achillededoncker:
I'm making an Arduino robot with mecanum wheels. For this, every wheel needs its own stepper motor and own driver module. I'm using 4 NEMA 17 - 0.52N.m - 1.5A Stepper Motors and 4 A4988 Stepper Motor Drivers. The drivers need a voltage from 8-35V and a max current of 1A (2A at peaks).

To power this, I want to use an 8x AA battery holder, so I get a total of 12V. I'm pretty new to electronics, so my question is probably pretty simple: Can I use the same battery holder for all 4 Stepper Motor Drivers? Or will every Driver require its own battery holder to work correctly? Keep in mind that I'd like to be able to use the robot for a few hours before having to change the batteries.

Before anything else you should consider that a A4988 driver doesn't handle 1.5A. 1.0A is the
normal limit (remember the spec in the datasheet assumes infinite cooling, its not relevant to
the little A4988 modules which aren't liquid-cooled (!!)). I'd suggest DRV8825's instead.

12V is a little low for stepper drivers, the higher the voltage the more speed you can get as its
the limiting factor for rpm. Steppers are inefficient so for battery use you'll need plenty of capacity,
not just the current handling.

Most NEMA17 steppers are about 5W, so that's 0.4A each from 12V, not counting driver losses,
I'd actually double that figure to 0.8A per motor. For a 24V supply you'd simply halve the current
requirements. LiPo, LIFePO4, SLA, NiMH pack are all possible approaches, alkaline AA's are not
promising at all for this. Cheap battery holders are not designed for high current, note...

One supply can handle everything, a supply is a voltage supply, thus the loads are independent of
each other so long as the supply isn't overloaded.