For battery chargers we don't use the Andymark ones because we find they are too expensive.
For a long time we have been using these chargers, they are similar to the kit of parts chargers but a little smaller and normally a bit cheaper. We've bought them for as low as $23.
http://www.amazon.com/Raider-AA-023-.../dp/B003Y3UFMS
This summer we purchased one of
these that can trickle charge up to four batteries at a time with an adapter. We've been using it in our shop and haven't had any problems yet. We'll be doing some testing soon.