One of my reason;s for using the Optima's is No offgassing. The area I have them in has way to much stuff that could be affected by that. They also don't leak and cause corrosion on the terminals like a wet cell battery.
Minkotta battery chargers work Very well with Optima's.
Minkotta 440. This is one BIG charger on a 23ft boat and it's heavy too.