[StinkyMatt]

If you want the fastest( or at least what I think is the fastest way to charge up you battery, hook it up with jumpercables to a car battery. This will very rapidly recharge your battery. Yes, there is a small danger of recharging VERY run down batteries as they suck juice quicker and may heat up. I dont think anyone here drains their batteries completely running a FF.

Now, this set up is if you really are in a rush and need a good kick in the butt charge for your batteries. This works quickly in a bind if you need them up NOW.

I have done this with various batteries while camping and fishing.

The best way still is to use a smart charger that will charge up slowly. From my understanding (like some other poster said) slower charging cycles will likely prolong the life of your batteries.