I've got a motorised camera slider running nicely on AC but need to have it portable. Can someone recommend a suitable battery setup for this application? I had it working on a 6pack of Li-ion AAs with a 5v servo but it was too loud. Changed to 5v stepper but not enough torque so i decided to go for a Nema 17 which has plenty.
Under the impression that all Nema 17s were 12V, and figuring the arduino can regulate down to 5V, I figure I need a 12V battery that I can split to power both. I searched ebay for 'Lithium 12v Battery' and bought one of those cheap chinese things wrapped in blue plastic. It fits perfectly size wise, has DC plug that fits Uno and a charging socket. When I hooked it up this way with the AC charger plugged in at the same time, everything works awesome. The stepper has so much torque I have trouble stopping it with my hand. Problem is when I pull the AC power, it only works for a minute or so before failing. It seemed to work for a while the first time I charged it but now it's got nothing even after charging all night. (I pulled this battery apart to inspect and it seems to be a series of waver like cells bodged together and a whole lot of empty space. I very much doubt the 3000mAh printed on it.) I think there's too much current draw for this dodgy pack.
So, I need something like this, but that actually works. I'm even more confused now as my stepper apparently has these ratings.
2 Phase bipolar 4 wires Rated Voltage 2V DC Rated Current 1.2A
2V is far from 12V that i originally thought, though it works great at 12V. So, should I use a pack of AAs? Will they provide enough current? What voltage should I aim for considering the stepper rating? Are there other, better made battery packs like the one I bought from ebay, but that actually work?
Chunky SLA type things like motorcycle battery are not an option. It needs to be slim and flat and not too heavy.