You're not going to screw it up. If it is a Ni-cad you may leave a memory, but you won't screw it up. To clear the memory you will just have to give it a good discharge at some point. I would suggest just going out and getting a nice long lastin gNiMH cell to pop in your glow ignitor. If it is an NiMH already, then you have absolutely nothing to worry about.