Spring refresh -updated Battery Charger selection

Looks like I am going to be updating the battery charger on my 2001 340 SD. After going through my Spring launch checklist and reviewing some of the things I need to do to re-install the genset in the boat (Previous owner removed- I cleaned carb and tuned over winter), I noticed the batter charger is plugged into a crimped on Female end to what should be a hard wire. So this sends me down a rabbit hole, turns out the Samlex power sec-1230ul charger installed in the Bilge by previous owner is not ignition protected.

Time to replace. I was already planning on updated the lead acid batteries this year to size 27 or 31 AGM. That would be 2 banks of 2 or a parallel bank of 2 port and 1+1 stb and genset.

The boat is Dual 30 Amp from a shorepower. I have narrowed it down to the ProNautic line. (Open to other suggestions)

What issues are there installing the ProMariner 40 Amp ProNauticP 1240P Battery Charger over the 30 Amp? Is it really just the cable size on the DC side I need to account for?

I replaced my OEM 30 amp with a Pronautic 1240P. I have two banks. One is a pair of dual cycle high capacity group 27 lead acid maintenance frees. The other bank is a pair of 6v Rolls Surrette golf cart batteries with 240 Ah capacity each at 6v (and total at 12v) The install was dead simple, but.....

After my first long weekend on the hook, when I returned to the marina and plugged in, the charger kicked in at a full 40A to the 6v bank since it was really drawn down and did not charge a lot on the short trip home.
I did not notice, but it blew the 30A inline fuse on the line feeding the 6v bank. So they did not charge and two weeks later when I was back at the boat, they were pretty much dead.

So, I then reconfigured the wiring and added 40A fuses on the feeds. Others have said that they do not have in line fuses on their boats. I am pretty sure they were Sea Ray OEM on my boat, but cannot guarantee it. It has been 100% fine since then and my experience with that charger has been great.

I just replaced a 1998-ish Charles Industries charger with a ProNautic 1220P. It was very simple to do, just making the proper connections.

I'm also considering replacing the Xantrax 40A on my Back Cove with a ProNautic 1250P so I've been looking at the considerations as well. You do need to consider if the wiring to the batteries is large enough. The thing is - it's the ROUND TRIP length of the wire that determines the proper gauge, not just to the battery. You also need to consider the size of a thermal breaker, if you have one. My install has a 50A thermal breaker in the line that's mounted to the batteries. The standard says that the breaker should be 1 size larger than the battery charger output. I would be going from 40A to 50A, so would need to upgrade the breakers from 50A to 60A. If you upgrade from 30A to 40A and have a thermal breaker it would need to be changed from 40A to 50A.

Old charger



New charger.

+1 on the Pronautic 1240P

I had the 1220p on our 290 (driving two banks) and I have the 1240 on the 410 (charging 3 banks - 2 mains and a genset battery)

No issues so far. I might add the victron monitors versus the promariner remote panel though, reviews aren't steller on their remote station. Other than that it's been great

Sterling is supposed to be identical to the Promariner but lower cost. I have the Promariner 1230 in my 370 DA and just put a Sterling 1250 in dock neighbors boat. I agree with prior comment on Promariner remote usefulness. Just tells you the total amp output, with nothing specific about individual battery bank. I put the Promariner emote in my 370.

I ended up going with the 1240p. Amazon had it for 489 direct and had some Gift cards to burn.

Going to replace my lead acid with AGM. Had to go to 2 different Sam's club, but got 4 Duracell 27M AGM for $168 a piece.

So for the 1240p, do I hook up the chassis ground to the bus bar or bonding system on the SeaRay?

Also last charger didnt have inline fuses to batterys. Do I need to add those?