Having just fitted a new Optima bluetop 75ah battery to my new 250as in place of the sealed leisure battery that comes with the new boat. I decided it was time to now plug in the shore power which also comes as standard and try the Pronautic battery charger which is a standard fitting on new 250s.
As recommended by Dan at EBY, "Yeah, you just connect up your shore power to the supply and it all lights up and comes on automatically".
It does indeed Dan, BUT.. the standard default setting on the Pronautic battery charger is for a sealed battery, ie the 'wet' sealed leisure battery fitted as standard on new boats.
Having left mine on overnight, I disconnected the shore power the following morning and started the engine to make sure I hadn't killed the battery or something, as I haven't had a lot of luck with this boat since getting it from new and I also wanted to see if it improved the bow thruster problem, which it did not, that still wouldn't work. (new bow thruster motor coming under warranty).
What I did notice though was that on start up, the plotter shut down - a problem the new battery had corrected. Strange I thought, it was okay yesterday when I started her up on the new battery, now since charging it I'm back to that problem again?
The Optima batteries are 'AGM' (absorbent glass mat) dry batteries, which charge differently.
Having read the Pronautic handbook, I realised that you can re programme the charger unit and it has a list of battery types to choose from including AGM. I swiftly did this and found that on this mode it actually puts a bit more voltage into these deep cycle batteries when on the AGM setting.
Praying that I hadn't damaged the new battery, I connected up the shore power and reprogrammed the charger for AGM. It went into 'conditioning' mode and stayed like that for about half an hour before switching to 'standby' mode. There are a sequence of lights on the front of the charger telling you what's going on.
I disconnected the shore power and started her up again and was pleased to see that the plotter didn't switch off.
So, obviously it is important to alter the setting on these new standard fitting battery chargers to suit the type of batteries you are using, and seeing as most of us are choosing Optima AGM ones over the Numax leisure battery that are supplied with new boats, you must remember to adjust the settings on the charger or you will recondition your Optima and it won't work as well as it should.
I'm no expert on batteries and these comments are based on my personal experience and advice given to me by on site marine engineers.
Hope my experience helps others.