Installation notes: ProMariner ProIsoCharge battery isolator

echandler1971

I have another concern now. The Proisocharge 2x4 unit has a 130amp rating. I believe each of the VP 5.7 GI-E alternators put out 75 amps each after checking for a new OEM alternator for an engine and getting the specs. Is the 130 amps per input or total? I'll have 2-batt house, 2 starter batteries, and 1 bow thruster battery - 4 banks total. I don't see any other models with higher amperages.

Edit: Notes on Dual Alternator Installation: In the installation of a dual alternator unit ensure the output wire gauge size is capable of conducting the total current of the two alternators. As an example in the case of the ProIsoCharge 130 2-4 connect to two 120 amp alternators ensure that each of the cables to the 4 battery banks is capable of conducting 240 amps. Found it in the manual buried. So, yes, it can handle it.

LaRea

LaRea said:

... Whenever I turned on the ignition, the isolator would make a loud, fast clicking sound, like the sound a ratchet wrench makes when you spin it backwards.  And it was not charging the batteries.  In other words, epic fail.  

... ProMariner says it's a known problem involving "relay chatter, which can be caused by noise on the ignition lines of some engines."  They sent me a filter ... basically a small circuit board that bolts onto the front of the isolator.  It's not the prettiest thing in the world, but it solved the problem.

One more follow-up.  The filter board that they gave me 18 months ago failed.  I asked ProMariner to replace filter board.  Instead, they sent me a brand-new isolator (the newer model, which has the filter built-in).  

So if anybody else has an early model ProIsoCharge with the external filter board, keep an eye on it.  If it fails, ask them to replace the unit.  Their customer service is excellent.  

YYZRC

That’s classy of them but honestly I wouldn’t have accepted that external board as a solution. 

LaRea

Well, the replacement unit failed after a month.  I'm trading emails with ProMariner to figure it out.

As I've learned, this problem isn't new to ProMariner, and it's not related to Mercruiser.  I saw discussions on a trawler forum from 2016.  But I did learn this:  if I reset the unit by disconnecting all batteries for 30 seconds, the relay chatter goes away and the system functions normally (a temporary fix, apparently).  

I'm gonna be ticked if I have to scrap this unit and switch to something else.  

Aqua_Aura

This is the new unit with the filter built in? The filter failed or the whole unit quit?

LaRea

Same as before -- relay chatter, and it only charges battery #1.  

YYZRC

I would go with a Victron Energy setup if I could switch both the charger and the isolator.   I would do a charger/inverter with a big lithium battery pack.

Next boat.

Liberty44140

Very interesting. My in laws have a two bank pro mariner on their 1974 Trojan 32 fly. It’s 2 years old with newer batteries. Got a call last Sunday morning at 7am “we’ve been hand pumping the bilge for two hours, carpet is wet, please come help”. I found one of the batteries completely dead and not charging yet the other bank was charged and charging. Was able to get the bilge pump on the other battery to pump her out. Replaced the bad battery and it has been good and charging. I was blaming the battery but perhaps it’s the charger?

oh and I also found a freshwater line with a cracked fitting which was filling the bilge with water. Fixed that too!

Cableguy Greg

Ugh… I have been recommending these chargers on the Facebook page all of the time. Mine seems to be holding up well, but I have a single engine. I hope they can get the issue resolved for you. 

LaRea

Don't blame the charger ... my Blue Sea Systems P12 is working fine.  It's only the ProIsoCharge isolator that is causing problems.  

Liberty44140

LaRea said:

Don't blame the charger ... my Blue Sea Systems P12 is working fine.  It's only the ProIsoCharge isolator that is causing problems.  

Ahh, ok good to know 

Cableguy Greg

I have the ProMariner charger along with the single engine isolator. I will keep an eye on my isolator. Maybe is just the 2 input isolator that has an issue. 

echandler1971

I finally completed my install. Boat still on the hard with freeze warnings still so could only test that ignition power did the needful. I have 4 banks (bow thruster is 4th). 

LaRea

Looks like yours is tucked away in a hard-to-reach spot.  Fun job, eh?  

echandler1971

It's above the stbd FW tank right were the old isloator was. There was enough room to maneuver there, although not without some bruises on legs and arms from prolonged contortionism. Hardest part was the run to the helm, although ringing out all the cables/destinations took time too, as I wanted to make absolutely sure port and starboard alternators/batteries were matched up.

LaRea

Same here.  But it's a necessary repair.

YYZRC

Well, I noticed that my engine batteries were a bit low last weekend while out and today I discovered that I have the dreaded ProIso relay chatter. 

Let’s see how they respond as I refuse to install the ghetto add on module that they sent @LaRea - I question whether that thing is ignition protected. 

LaRea

Ironically, I was also getting relay chatter last week.  I did the reset by disconnecting all batteries from the isolator for 60 seconds.  When I reconnected and started the engines, no chatter ... BUT now the alternators are not charging the batteries while underway.  

This is with the new isolator they sent me 12 months ago.  

I haven't had a chance to contact them yet.  You should mention my name ... I'll PM you.

YYZRC

I will - after hearing that, I think I will switch to a Victron isolator. 

YYZRC

@LaRea rather than fully disconnecting at the isolator, can I just turn the batteries off?

LaRea

No.  I tried turning off the battery charger and all battery switches, then disconnecting the power cables from all four batteries.  The isolator didn't reset.  A few days later, I disconnected the wires from the isolator, and the chatter stopped.  Maybe there was a latent current from elsewhere on the boat.

When this unit is working, I'm happy with the performance.  I'd hate to admit defeat and get something else.  

Grahamu

What is the advantage of the Promariner Isolator over a standard Isolator which I have kept and have no charging problems.

YYZRC

It's more efficient as it doesn't use diodes which result in voltage loss.  Saying that, I don't see any upside to the ProIso with my setup as I have solar to supplement the alternators for my house bank.

I just ordered two Victron Argofet to replace the ProIso.  Boating season is too short to put up with shoddy products.  Hopefully they send me a new ProIso that I can throw up on eBay and recoup my losses.

Grahamu

The only time there is a voltage loss is when alternators are supplying the charge current. In a 24 hour period that's probably on average less than 10 percent of charging. I don't worry about my start batteries they are no different to my car battery. My house bank of 4 golf cart 6V batteries are always fully charged before leaving and I have anchored for 24 hours with no charging and I have never reached 50% discharge.

YYZRC

Right - if your existing isolator is working fine, no justifiable reason to replace with a non-diode (FET) isolator. For the Victron units, the price difference between FET and diode is only a few dollars.

goalie59

The new isolators require additional wiring from both ignition keys. The old diode isolators seem to last forever . If I change mine I will stick with the pro mariner diode model. They still make them. 

echandler1971

I have the same ProIsocharge, install at the beginning of the season. It's buried in the engine compartment, so I don't even know if the relay is flapping or not. I'll definitely have to take a look at it.

LaRea

Turn off all noise sources (radio, blower, etc.).  Then turn the ignition keys to the first click, but don't start the engines.  You'd definitely hear it in the cabin, and probably at the helm too.  It sounds like a really fast clacking sound.

YYZRC

Here’s a video of the relay chatter

https://youtu.be/whZvqxCh5mI

Spyderweb

Whoa, I guess that does chatter!