If I'm powering a device with a series-connected stack of rechargeable batteries, can I pull different voltages at different points and route them to different components? I need to run a 12V solenoid, an Arduino (6V-12V recommended), some stepper motors (around 5 or 6V), and possibly a servo (though that can probably come straight off the Arduino).
If I have, for example, four 3V cells, can I grab 6V from two of them and 12V from all four at the same time, or will that do bad things to the cells' relative charge? Space and complexity are constraints here, so adding a regulator might be possible but would make things more complicated.
Alternatively, would using higher-capacity cells adding up to 6V and a boost converter to get the 12V work? I'd be concerned about current, but my fears might be baseless.