I'm certainly not the best qualified to answer this but I do know that the first question is going to be "Just what do you want to charge?"
I use two Oxford Optimisers for my 12 v 7ah batteries, of which I have quite a few, and they are always kept in good condition but for smaller stuff I then use a Hitec CG-340 to charge stuff such as Rx packs, Tamiya packs and other assorted batteries. This set up allows me to use either 12 v 7ah batteries in most of my models and a spare battery in my tool box can be either used to replace one that is going down or to charge up any one of the smaller ones via the Hitec. I can also use the Hitec from the car battery so lots of flexibility.
