http://www.greatgrady.com/forum/viewtopic.php?t=9238
Pro Mariner makes a decent charger and I believe is the one most have recommended to replace the Guest one with. My Guest has been replaced once when we purhcased our boat by the previous owner on delivery, it is 2 seasons old and acting up already, I would avoid them honestly. Guest chargers are a cheap bottom of the line charger and do not last long. Charles, newmar and xantrex are better quality then the pro mariner, but will cost more. Where I work we build high end sportfishermen and have used the previous 3 brands and were very pleased but have since gone to mastervolt chargers, they are very high end and very expensive, but also very sophisticated. Not nessecary on a boat our size. I plan to replace my guest with a xantrax or charles charger, but the pro mariner is not far behind due to simplicity and price. Xantrex is my top pick but not positive I have the space, a Charles C-Charger would fit and might end up as my replacement...still doing some research though, might be some new chargers by spring. As for installation, it is not overly difficult if you are somewhat handy and can follow directions provided. ...Make sure the power is off first, and I'd recommend personally disconnecting the batteries and shore power as well to be safe.
