I have a Zenoah 20 which uses a single LiPo cell (3.7v) as the ignition supply and have been looking for a checker that will indicate when the voltage drops to 3v. I found a gadget that reads individual cell voltages in multi-cell LiPo packs but it won't indicate for a single cell. Anybody know of a suitable widget that can be left connected in parallel to the cell in the aircraft to indicate the cell state? Alternatively is there an electronics guy out there who can come up with a suitable circuit to do the job? - I'm OK with soldering components etc.