RE: How do you fully discharge a Dynamite glow plug thingy.
I keep two rechargeable glow drivers and one can take a full C size so I keep an Alkaline C for extra backup. I just use them and charge it only after it's dead. Cycling really won't help, because there is no issue with a reliable drop off, plane won't crash, etc. Also no issue with partial recharging. I have had a glow driver battery last over a decade. Yes it needed frequent charging to the end, only getting just over half a dozen starts per charge towards the end, but it worked so I used it.