went to lithium batteries last week. I want a charge on the fly charger. trying to decide a stealth 1 or yandina. I don't care for the 30 second delay deal with the trollbridge, and I e-mailed them with questions and they didn't bother to respond. I know stealth has been around for a long time and never heard anyone say too many bad thing about it, anyone with experience with either or both ??