I have been researching the battery charger on the Hunter for reasons previously discussed here(not wanting to get zapped). I found the model and downloaded the actual owner/operator/installation manual and found some very interesting things.

First, although the boat owner's manual supplied by Marlow-Hunter refers to the unit as a charger/inverter, it is not. It is just a battery charger and not a very smart or capable one at that.

Second, the ProMariner-4 series has been discontinued, I think a good decision by them. Having read through the entire manual, this charger is not a very smart unit which explains things. In the past I have been very fond of a series of chargers that were fairly small, inexpensive, trouble free and available through many sources. I installed them on at least three of our boats that I can remember, one charger per battery. 3amps charge plus a float setting that kicks in automatically when the battery is fully charged. Although these were not bass boat trolling battery capable, we never had an issue, the boat batteries were always topped up. The ProMariner on the Hunter is only slightly larger, 5amps charge per bank, however there is nothing automatic about it. There are a series of dip switches that need to be set in proper sequence for the battery size and type. You can adjust the charge cycle for 1,2,3 or 4 hours after which time the charger goes into float mode. The boat was equipped with two group 31 batteries from the factory, at some point the mechanic who "professionally maintained" the boat for the PO installed two group 24 replacements. Although I have not confirmed yet, I have a strong hunch that this guy never read any manual and never reset the dip switches down to group 24 mode. That means they have been getting the crap charged out of them for however many years they have been in the boat, which would explain why they were boiled dry. This charger doesn't know or care that a battery is fully charged, only how long you told it to jam 14.7 volts into them.

Third, it cautions the owner NOT to mix battery size or type with the charger. Having a group 24 start and group 31 house battery will get you either an overcharged group 24 or undercharged group 31 depending on how you have the dip switches set. You also can't mix a gel and traditional flooded for the same reason.

So, all of those things said we have a case of good news/bad news in that I don't have to worry about getting zapped from a 120v circuit while unplugged from shore power, but have only a marginally capable battery charger installed.