I've done a lot of searching here and with Google but haven't found the answer yet. I'm developing a project that uses a stepper motor purchased from SparkFun (the ROB-09238). It needs 12V.
On my development Uno I currently have a 12V wall-wart power supply plugged into it and am powering the motor with a lead from Vin. The current draw should be low as the motor will be slowly moving a wheeled or slider platform about 3' max on a horizontal surface.
When I move the project to a portable platform I'll need 12V battery power. I could probably buy something like a 12V motorcycle battery and have some long leads. But that is big, heavy, expensive and overkill. If I could wire up some lithium ion or other batteries in series to get 12V that may work. The lithium ions I'm seeing for sale ar 3.7V, so three in series would only give me 11.1 at a full charge. Maybe use 4 in series? They can also be expensive.
Suggestions on a portable and prefereably inexpensive ( less than $30) 12V battery supply would be appreciated. Small and light if possible would be great too. I'm willing to make my own by rigging up batteries in series.
p.s. the project is a DIY motorized camera slider for time-lapse photography.