So I need a power source for my pre amplifier.
I need ~4-5 volts per rail.. (bipolar)
two options come to mind:
4x lithium battery for +-6v. I like this solution because I could seal the whole thing up well and just leave a external jack and switch to plug it into a lab power supply for charging (I don't expect this thing to be used much).
rechargable c/d cells - I don't know how many I need, 6 I assume (1.5x6 for 4.5--4.5v).
The problem is that I don't have a charger for these cells, so I would need to buy one, since you can't recharge certain battery types with a lab power supply (I would need to keep track of temperature and its kind of a pain).
I have eneloop AA rechargeable batteries. They are nice but they are only 1.3V, so I would probably need four of them per rail, and that is not much current (I expect this to take ~50-100mA).
Eneloops would cost 20$ and require dis assembly for recharging.
I am not sure what type of lithium battery I would use, I 3000+mAh would be nice.
I wanted to run the op-amp just from the batteries without a regulator to keep the circuit simple.