ProMariner 20-amp 3-bank charger

[Hookup1]

I have used this charger for 10+ years now. I had one fail but I replaced it with the same. These charges bank shift the charging amperage based on need but are capable of directing all 20 amps to one battery. In my case the twin engines do a great job of charging the starting batteries. The house battery is the one that gets run down (it is charged from starboard engine when running).

ProMariner fuses the battery connection with a in-line glass fuse in a rubber holder. Since the house battery needs more charging amperage and I'm usually running bait pumps all night I have had problems with the fuses heating up, melting the holder and sometimes blowing the fuse leaving me with a dead house battery and bait in the morning.

When charging you can put your hand on them and they are hot to the touch. When you try to open them up the fuse shatters. I tried ceramic fuses too but when the holder melts its still a mess to get apart. Here are the OEM fuse holders:

To get around this I went to waterproof automotive blade type fuse holder.

I bulkhead mounted them and all is well. This is only the house battery. I use the OEM fuse holders for the engine batteries and they hold up fine.

 

[Timbo]

I would consider upsizing to a heaviest wire or a battery with a higher capacity

 

[Hookup1]

I would consider upsizing to a heaviest wire or a battery with a higher capacity

This is the factory standard charging harness on the ProMariner charger. Everything is fine except for the factory fuse. Great charger.

 

[SkunkBoat]

I have same charger. It has worked really well. Two DP24 Starting batteries and I put two DP24s in parallel as the House. Start batts charge from respective motor and House charges from both motors' aux charging cable. I haven't had the fuse melting problem but I don't run livewell that often. I do run full electronics and LED spreaders all night on canyon trips.

Are you running the pumps at the dock while on the charger?

 

[DennisG01]

There was likely corrosion or frayed wires inside the wiring at the connection of the fuse holder. That would cause heat buildup. Glass fuses will work just fine - the actual switching to an ATC style fuse wasn't the solution, per se. It was that the wiring was replaced.

 

[HMBJack]

Coincidentally, I too have experienced this - but on ProMariner 30 amp charger with 3 leads.

I had 2 of the 3 charger leads going to my Port Battery bank and 1 charger lead going to the Starboard battery bank.

Like you, my starboard bank feeds the House. So, when the Starboard bank gets low, the ProMariner, in my case, was sending all 30 amps to the Starboard bank. This proved too much for the 30 amp fuse holder (got hot and melted).

My solution was to simply move 1 of my 3 charger leads from Port to Starboard. So now, I have 2 charger leads going the Starboard bank. When the House bank draws it down, the ProMariner now splits the 30 amps across the two Leads at 15 amps each. Problem solved. No hot or melted fuse holders...

The better scenario is to not let the House (Starboard) Bank get so low.
I now start my generator sooner so as to allow the ProMariner to not have to work so hard.
Better yet - maybe I should run my generator all the time - as in when I leave the slip.

Thoughts? Comments?

 

[Hookup1]

This is my second ProMariner charger. I had fuse issues with both of them. There are 5 inline fuse holders. I inspected all of them. No water intrusion. Three of them were perfect. I left them unchanged except for a ceramic fuse instead of a glass fuse. The two that go to the house battery were damaged (plastic melted closed). I re-used the wires for the ATC fuse holder - it was clean tinned copper.

Think what you want but if you have one of these chargers keep the fuses in mind if you start having charging problems. Also grab the house fuses when you are charging at the dock to see if they are running hot.

 

[Hookup1]

Coincidentally, I too have experienced this - but on ProMariner 30 amp charger with 3 leads.

I had 2 of the 3 charger leads going to my Port Battery bank and 1 charger lead going to the Starboard battery bank.

Like you, my starboard bank feeds the House. So, when the Starboard bank gets low, the ProMariner, in my case, was sending all 30 amps to the Starboard bank. This proved too much for the 30 amp fuse holder (got hot and melted).

My solution was to simply move 1 of my 3 charger leads from Port to Starboard. So now, I have 2 charger leads going the Starboard bank. When the House bank draws it down, the ProMariner now splits the 30 amps across the two Leads at 15 amps each. Problem solved. No hot or melted fuse holders...

The better scenario is to not let the House (Starboard) Bank get so low.
I now start my generator sooner so as to allow the ProMariner to not have to work so hard.
Better yet - maybe I should run my generator all the time - as in when I leave the slip.

Thoughts? Comments?

From what you described you have two batteries and a three bank charger. Two of the charger banks are connected to the Starboard side. That would distribute the charging amperage to across two fuses allowing them to run cooler. Make sense.

I don't have a generator so I never shut my engines down - they are my generator. The Yamaha alternators are efficient even at idle (see charging curve below). With all the electronics and two live wells (500GPH and 1100GPH) I would run the house battery down during the day and get low voltage warnings on the Garmin display.


Back at the dock the house battery probably isn't that low. I think the problem is running pumps and electronics off the charger.

 

[DennisG01]

Interesting to hear about a second, similar case. All I can say is that this is very much "not" the norm - but interesting. I have owned a couple PM 30-amp chargers (ProNautic model) and am very, VERY familiar with them. In fact, I have experience with, literally, a couple hundred of them (20a, 30a, 40a and 50a) as the primary boat brand I work with used them for a few decades. I can't ever recall coming across this issue, before.

And, just to be clear, again, what I'm mentioning isn't based on a personal experience or two - it is based on familiarity of hundreds of models.

For transparencies sake, the type of power being run on these boats is things such as fishfinders, lot's of cabin lights, stereos, refrigerator/freezers (sometimes two of them) - "cruiser" style boats.

Maybe the big difference is the live wells - but I still think there may be more going on than just the "style" of fuse. I mean, these style of fuses have been used (as I'm sure you know) pretty much "forever". However... thinking about this... the "contact" point inside the glass fuse may be a smaller contact point than the ATC. So if some moisture got in there, it likely wouldn't take much corrosion to degrade the connection and heat things up. And adding more to this "thinking"... the boats I work with (Sea Ray) tend to have MUCH drier bilges than the Grady's. As an example, my last Sea Ray... I could get down in my bilge and stand in front of the engine (stern drive) - even sit on either side of it - with nice pants on, none-the-less... it was always pretty much bone dry.

Hookup, I was going to say that when you installed the ATC maybe you used larger gauge wires - but if I understand you correctly, you reused the existing wires?

If for nothing else, though, it's a good "public message" thread and certainly deserves to be mentioned!

With the "moisture" in the bilge in mind... another PSA would be to once a year check all electrical connections... remove, clean and reinstall with a LIGHT smear of dielectric grease (too much will prevent electrical contact) on the contacts. I even put some on the rubber sealing surfaces before reconnecting. NOTE: I mentioned "dielectric" becasue most people have easy access to it and it's inexpensive. But the product that I actually use for electrical connections is called "Tef-Gel". It ain't cheap, but it's about the best stuff you can get.

 

[HMBJack]

Like others in a 330, I have 4 batteries: 2 on Port and 2 on Starboard in parallel. Group 26 sized Optima AGM's. I have my ProMariner Charger (ProNautic Model 1230P) set for AGM's.

Like Hookup experienced, I had a condition where my House batteries ran basically to zero volts due to my shore power going out on me during the night with my two Live wells running (1,100 GPH Shureflo Bait Sentrys). In the morning, the live wells, the bait and the House Bank were all DEAD as a doornail.

I think my single fuse holder to the pair of House Batteries got hot and melted as the ProMariner tried to pump 30 Amps through that one Charger Lead.

By now putting TWO Leads on the House batteries (one on each battery connected in parallel), I think my issue went away as each lead will carry a max. of 15 amps each.

Below is my melted fuse. It holds a 40 amp fuse (per Mfg. spec.) and at 30 amps, it didn't blow.
It just melted then caused the charger to go into Fault mode. I of course removed and replaced this fuse holder.
Scary to see this happen!

 

[dogdoc]

do not understand some of the logic in battery set ups in the posts above. seems logical to me that each bank should have a dedicated use, ie if 3 banks and 2 engines (very common set up) or 2 banks 1 engine also common then one bank to each engine and one bank for house. bat switches could be configured to modify use of each bank on the fly if need arises. as for charging, chargers have gotten much smarter than batteries these days. 2 banks, 2 bank charger, 3 banks 3 bank charger and as smart as you can afford. distributive charging of the promariner/pronautic line is great. when dealing with 30 amps inline or blade fuses may be inadequate i use mrbf type in independent supply block placed as close to source (charger) as possible

 

[drbatts]

The same thing has happened to me with two separate pro-mariner changers on 2 separate boats with different battery setups. On my 265, When it was on the dock, I would leave the shore power plugged in with the battery charger and the 12v fridge on. My shore-power was accidentally unplugged, the fridge ran the house battery down. When I plugged the charger in to charge it, My fuse burned up like the one above. With my 305 with a newer promariner charger and 2 battery banks. One bank ran down and again the charger fried the fuse and holder trying to charge that bank. I was suspicious of the issue and now you guys are confirming it.

 

[DennisG01]

Although I still think that water intrusion/corrosion (even a slight bit) may be a factor, I was thinking more about it this morning and... ProMariner doesn't supply the fuse/wire for this since they don't know how close to the battery the charger will be. That is supplied/installed by the boat company (or person doing the install). This may better explain why I had never seen this issue with hundreds of Sea Ray installs - they may be using more appropriately sized wiring, as well. The fuse connection may be the "weak" link in the circuit and that could heat up before the rest of the wiring (and, of course, the fuse itself would/should be the weakest link by design).

I'm not comparing the two companies - just trying to think further into this as to the real "why" since the glass fuse (or the ATC as referenced by Jack), itself, isn't the problem. There are other factors that come into play. Between a wetter bilge and "possibly" slightly undersized wiring, that could certainly explain the problem.

All that said, it's a good post to bring light to an important thing to check.

 

[seasick]

For a short round trip run ( and I think the run is a lot longer that you might think) taking into account the ground wiring and a 10% voltage drop, the minimum wire size would be 10G for a 30 amp draw. For lower voltage drop and a 30 foot round trip, you are looking at 6G wire. The leads on that inline fuse look undersized and as a result would overheat.

 

[Hookup1]

Although I still think that water intrusion/corrosion (even a slight bit) may be a factor, I was thinking more about it this morning and... ProMariner doesn't supply the fuse/wire for this since they don't know how close to the battery the charger will be. That is supplied/installed by the boat company (or person doing the install). This may better explain why I had never seen this issue with hundreds of Sea Ray installs - they may be using more appropriately sized wiring, as well. The fuse connection may be the "weak" link in the circuit and that could heat up before the rest of the wiring (and, of course, the fuse itself would/should be the weakest link by design).

I'm not comparing the two companies - just trying to think further into this as to the real "why" since the glass fuse (or the ATC as referenced by Jack), itself, isn't the problem. There are other factors that come into play. Between a wetter bilge and "possibly" slightly undersized wiring, that could certainly explain the problem.

All that said, it's a good post to bring light to an important thing to check.

Dennis - All the ProMariniers I have bought or seen have pre-assembled cables fixed length with fuses. I can only speak for the 3-bank 20-amp. My bilge is pretty dry and I can tell you the fuse holders are well sealed and dry - until they burn up. So maybe the OEM chargers are different then the retail ones. If the wiring is undersized its on ProMariner in my case.

All I can say is the chargers are great but beware of fuses particularly on the house battery. Replace if necessary.

Also - in addition t my pumps my fridge is running all night too.

debatts problem was exactly mine. The house battery fuses would overheat and pop. Fridge and pumps running all night would kill battery. After much checking I would find out I'm not charging and one of the fuses were blown and the holder melted. It almost happened to me this year in Islamorada except that they melted and ran hot.

 

[SkunkBoat]

It may be that the fuse holder contacts are the point of highest resistance (due to oxidation or poor contact). That is why the fuseholder melts but the fuse does not blow. There is not too much current, there is too much resistance. I have seen the same thing in fuse blocks(especially ATO fuse blocks).

It may also be related to running the live wells and/or DC refrigerator while the charger is connected. The charger is designed to cycle charge a battery but you have a constant current draw. That constant high current over a long period of time "cooks" the fuseholder. ( in other words, you are using the charger as an AC to DC power supply)

 

[Hookup1]

I suppose. But what good is a charger is you can't have a load on it at the dock? Every boat (small and large) I've owned and large sportfish I work on have a demand for 12/24 VDC at the dock.

I discussed my situation with ProMariner engineers too. No problem with how I was using the charger. The only strange thing they told me was to connect the wiring leads closest to the power cord on the unit to the house battery followed by the engine batteries. They never explained themselves but it probably has to do with how the charger scans/prioritizes charging.

I have to look at fuse holder ratings for intermittent and continuous load specs. All I can say is the AGM fuse holders I'm using are #12 AWG and waterproof (at least resistant). When I installed them on my old charger I never had the problem again. I just did the "new" charger that had the melted fuse holder problem for a while. I'll report back in February how it's working out.

 

[Hookup1]

Both styles of fuse holders are too close to the edge.

3AG holders max out at 20 amps.

Fuse Holders - Littelfuse

www.littelfuse.com

Looks like the ATC holders are on the edge too. Max is 30 amp fuse holder.

http://www.farnell.com/datasheets/2059883.pdf

 

[Seafarer_Bob]

Since the house battery needs more charging amperage and I'm usually running bait pumps all night I have had problems with the fuses heating up, melting the holder and sometimes blowing the fuse leaving me with a dead house battery and bait in the morning.

I don't understand this. Are you running your 12v pump and accessories and blowing fuses while you're charging at the dock or are you blowing fuses on your charger while you're at sea disconnected from AC? The latter wouldn't make sense unless you have a generator.

Either way I don't think it should matter. If the charger is rated for 20 Amps each bank should have a 20 amp fuse so they shouldn't be blowing unless you're getting bad AC power.

I had a Pro Mariner I my last boat and it mysteriously died the one time I tried to charge my batteries from a generator, the circuit was supposedly protected but I think I got a major surge.

 

[Hookup1]

It happens at the dock overnight while under load. I don't have a generator but a generator should be treated as shore power if you have it on.

Let's back up. I have owned this 1997 Islander since October of 2008. After I bought it the original battery charger quit and it was replaced with a ProMariner 3-bank 20-amp charger. First winter in FL with that charger I found the boat with no house power in the morning after running pumps and fridge overnight. Threw out my bait, started the engines and went fishing.

Back and forth with ProMariner engineers and at some point I found damaged fuse holder and bad fuse. I changed batteries unnecessarily before realizing it was fuse/holder.

Years later first charger (failed with no lights) and I installed a new one wiring and all. I should have upgraded the fuse holders for the house. I didn't, it never failed but was running hot and melted earlier this year. I upgraded fuse holders a few days ago.

I started this thread just to provide a heads up to users of this charger system to check to see how hot your fuse runs and maybe you should spend the $15/$20 to upgrade it.

It's worked for me. I analyze EVERY failure that happens on my boats/fishing. I'm satisfied with my conclusion. I hope it's helpful to someone else.