I'm trying to build a circuit that can power multiple sources with a single battery (rated at 18.5V but the charge is pretty unstable and could be anywhere from 16-20V depending). Among other things, the battery is powering several servos which are prone to producing back voltage when activated...what's the best way for me to fix this? I was planning on adding some sort of buffer, but thought it might be risky or simply impossible to power the buffer with its own input (the whole point of the system is for it to be able to run off a single battery). Appreciate any suggestions out there as I'm not very well versed with this sort of thing. Thanks!