My dads been using one for years (has an 8 year old original OEM battery in his car still), and I decided to get one myself. They have a 4 section programmed cycle for maintenance and charging of battery's. Main target is seasonal use vehicles which sit for half the year. They have a number of models, which range from a simple 30$ keep your battery nice setup 1.5amp up to larger units like the one I got.
Their products use a interchangeable tip to connect, and they offer tails which hard wire into the vehicle or a standard clip style. Pricing is reasonable ($5/tip).
I got a large model, which is vibration and waterproof (designed to be hard bolted into the engine bay) and charges at a max of 5amps. *note not all are water or vibration proof* Got enough hard wire setups for every vehicle I own for $20. Quite cool I think. The waterproof unit is nice as I can connect it up or leave on the trailer without worrying about it.
Anyhow, I love the form-factor and multi-tip hardwire design.