Two batteries, $275; New Charger $400, maybe it's the isolator

Tom Huntley

Tom Huntley

New Member
Sep 1, 2020
9
Boat Info
1999 400 Sundancer
Engines
Caterpillar 3116
I'm almost at the point of Breaking Out Another Thousand. The two starboard batteries were dead and not taking a charge so I bought two new batteries: Cost $275. Then I read that I might have killed the batteries (I'll spare you the details) so I bought a new state-of-the art ProNautic 63140 charger for my 400 SDA with Cat 3116s. Cost (about) $400. Installed that yesterday, and starboard batteries still not charging. Do I go for a $Grand and buy a new isolator? Needless to say, I'm very frustrated. Isolator is only other item in the schematic I have not investigated. SOS! Need help with identifying source of problem.
 
Installed that yesterday, and starboard batteries still not charging. D

Does the alt have any output?
Yes, then check the isolator for output, No ,check the alt
Isolator is just a diode ,check with ohm meter. continuity one direction, infinity the other direction
 
Bt Doctur said:
Installed that yesterday, and starboard batteries still not charging. D

Does the alt have any output?
Yes, then check the isolator for output, No ,check the alt
Isolator is just a diode ,check with ohm meter. continuity one direction, infinity the other direction
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It was getting late, so I didn't spend much time with my VOM. ProMariner suggest fuses between Charger and Batteries, but I don't see fuses in the schematic provided by Sea Ray. Today, I thought I would take some measurements at the charger lugs. ProNautica looks to be very sophisticated, but I'm having difficulty working through theory of operation. i.e. Three batteries (S, P, and G'set) yet no gauges. Actually not even gauges, but charging status LEDs. One side charges nicely, so I use emergency solenoid to start other engine. If I go for a small cruise, the alternators will charge their respective batteries, and that's why I have ignored the isolator as the culprit. Diode test makes sense, so I'll give it a try.
 
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How is your charger hooked up?

Are the charging leads directly to the battery banks or is it connected to the battery selector switch?
 
Little Ducky said:
How is your charger hooked up?

Are the charging leads directly to the battery banks or is it connected to the battery selector switch?
Click to expand...
This is a direct replacement to an older ProMariner charger that was original equipment, so I installed it using the same installation at original. Chasis ground to ground lugs on bulkhead, There are four lugs for battery charging. One is a common (-), and the other three are for battery (1) (2) and (3). Insulation of RED wires was ID's by someone else (factory?) with a felt marker as I, II, and III. Pretty sure I have installed as intended. Will do continuity checks today.
 
Check for in line fuses that may be blown on the wires that run from the charger to the isolator or to the battery switches. On my 97 there are (were) 30 amp inline fuses that blew after I upgraded to a 40 amp charger. I upgraded the fuses to 40amp and all is good now. Same symptom. I could not figure out why that battery bank would not charge fully. It was actually never charging after the fuse blew except when the engines were running.
 
Creekwood said:
Check for in line fuses that may be blown on the wires that run from the charger to the isolator or to the battery switches. On my 97 there are (were) 30 amp inline fuses that blew after I upgraded to a 40 amp charger. I upgraded the fuses to 40amp and all is good now. Same symptom. I could not figure out why that battery bank would not charge fully. It was actually never charging after the fuse blew except when the engines were running.
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This is a vert good thought, and it also fits well with the symptoms. The schematic does no show fuses, but some may have been added. I'll do a continuity check of each battery cable to see if that's a possibility. Today I ordered a ProMariner isolator for twin engine setup. The new ProMariner products are really well engineered. If this setup results in healthier batteries, I plan to write up the whole experience so people can learn from it. We'll be cruising the North Channel near you next summer. I hear it's beautiful.
 
I recently replaced my 28 year old factory ProMariner with a new ProMariner 44020. I had it professionally installed by a marine electrician. He wired direct to batteries, not thru perko switch, that way it is always monitoring and charging the batts regardless of switch setting. and there is an inline fuse for each batt from the charger.
 
Tom Huntley said:
This is a vert good thought, and it also fits well with the symptoms. The schematic does no show fuses, but some may have been added. I'll do a continuity check of each battery cable to see if that's a possibility. Today I ordered a ProMariner isolator for twin engine setup. The new ProMariner products are really well engineered. If this setup results in healthier batteries, I plan to write up the whole experience so people can learn from it. We'll be cruising the North Channel near you next summer. I hear it's beautiful.
Click to expand...

I think mine were OEM fuses. It may be hard to trace the wires depending on how they are bundled.
You will love the North Channel and Georgian Bay. I hope the borders are opened up by then.
 
Pirate Lady said:
I recently replaced my 28 year old factory ProMariner with a new ProMariner 44020. I had it professionally installed by a marine electrician. He wired direct to batteries, not thru perko switch, that way it is always monitoring and charging the batts regardless of switch setting. and there is an inline fuse for each batt from the charger.
Click to expand...
The OEM setup is effectively wired directly to the batteries. They wire to the battery side of the swtiches. So they are on all the time regardless of switch setting. I expect that they may have rewired the charger so that the wire gauge could be increased if the charger was a higher amp charger and was too big for the existing gauge wiring. They short-cut the rewiring by going direct to the batteries rather than trying to run the wires back to the switches.

I actually rewired my house feed for that exact reason. My house bank is a 6v golf cart bank and after a weekend at anchor it takes the full 40 amps from the charger to that bank. I wanted to ensure that the wiring was up to it, so I ran a new direct wire from charger to battery bank (not via the switch). It was easier that way. At some point I am going to re-wire it to the battery switch for a cleaner install and to limit the number of wires direct to that bank of batteries (I have a few other direct feeds coming off that bank for other purposes - downriggers for example).
 
Creekwood said:
The OEM setup is effectively wired directly to the batteries. They wire to the battery side of the swtiches. So they are on all the time regardless of switch setting. I expect that they may have rewired the charger so that the wire gauge could be increased if the charger was a higher amp charger and was too big for the existing gauge wiring. They short-cut the rewiring by going direct to the batteries rather than trying to run the wires back to the switches.

I actually rewired my house feed for that exact reason. My house bank is a 6v golf cart bank and after a weekend at anchor it takes the full 40 amps from the charger to that bank. I wanted to ensure that the wiring was up to it, so I ran a new direct wire from charger to battery bank (not via the switch). It was easier that way. At some point I am going to re-wire it to the battery switch for a cleaner install and to limit the number of wires direct to that bank of batteries (I have a few other direct feeds coming off that bank for other purposes - downriggers for example).
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Nope - there are circuit breakers behind the main 12V circuit breaker panel on the Port side of the cockpit of the boat. If the OP simply connected the existing wires to the new charger those wires run directly to three 50 amp circuit breakers (engine, engine, generator) then are routed to the battery side of the disconnect switches. Unscrew and tilt the circuit breaker panel downward and you will see the breakers... This is a pic from my old 400DA.
View attachment 91554
IMG_3613.JPG
 
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Regarding the isolator - hardly ever an issue but if the charger/converter is working on all battery connections the isolator will not prevent a battery from charging. If the isolator was bad it would only prevent one battery bank from charging the other.
 
ttmott said:
Nope - there are circuit breakers behind the main 12V circuit breaker panel on the Port side of the cockpit of the boat. If the OP simply connected the existing wires to the new charger those wires run directly to three 50 amp circuit breakers (engine, engine, generator) then are routed to the battery side of the disconnect switches. Unscrew and tilt the circuit breaker panel downward and you will see the breakers... This is a pic from my old 400DA.
View attachment 91554View attachment 91555
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Interesting routing and makes sense. I am not sure if that is how my 97 DA is wired. In any event, the OEM wiring for the charger is effectively wired to the battery side of the switches and may take a circuitous route to get there as you have explained.

I will have to check whether mine goes through both the fuses and the circuit breaker. It seems to me that by connecting to the circuit breaker it is a simpler way to achieve the result of being connected to the battery side of the switching circuit without running directly to a battery post.
 
Creekwood said:
Interesting routing and makes sense. I am not sure if that is how my 97 DA is wired. In any event, the OEM wiring for the charger is effectively wired to the battery side of the switches and may take a circuitous route to get there as you have explained.

I will have to check whether mine goes through both the fuses and the circuit breaker. It seems to me that by connecting to the circuit breaker it is a simpler way to achieve the result of being connected to the battery side of the switching circuit without running directly to a battery post.
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He may simply have one of the circuit breakers open....
 
Did you get this resolved?
Asking because I am in a similar situation. My starboard battery bank was fully discharged twice after the post-purchase relocation and haul out. After the first time, it took a charge off the converter and were operational. No such luck recently when I relaunched last week. The panel gauge would read zero and I used the jumper switch to start the stbd engine. While engine is running, I had voltage on the gauge and use of the dc items on that bank. i thought maybe after running the boat for the day that the bank may take back a charge, but nothing. After I turn the engine off, back to zero.
As the lead acid grp 27 batts were from 2016 I was planning on replacing them within the next year anyway. So over this weekend, I picked up all new group 31 AGMs and replaced all 5. Got everything installed, flipped the switches and same deal. The new batteries are all reading 13 to 13.2 at the terminals. the next place I checked was at the jumper relay (not sure what the proper name for that), but sure enough, no voltage here from the stbd side, but good from the port side. I pushed all 3 of those red button style breakers and all seem to be in the same closed position.
So, could the main switch have gone bad? I ran out of time and didn't get to remove the switch panel cover, but any other items I should be checking? The boat has a fairly new victron charger, which so far looks good.
Thanks, Vince
 
Boca_Vincent said:
Did you get this resolved?
Asking because I am in a similar situation.

Both sets of engine batteries charge well from their respective alternaters. I installed a new ProMariner charger, and still have an issue with the starboard pair of batteries when on shore power. If I come back to the marina after a an hour or so run, S and P sides are evenly charge. Problem is, if we use lighting and other 12V functions, the Starboard side is starts to run down and does not recharge on the converter. I'm going go run continuity checks on all wires associated whit the Starboard side, but just haven't gotten to it yet. Charger has output, but the system acts like it's open somewhere between the charger and the battery. SeaRays schematic does not show a fuse, but that does not mean one was added. I'm open the notion that a blown fuse could be the culprit. My boat is a 1999.
Click to expand...
 
On the topic of charging could someone confirm my thoughts on the following. Have just purchased a 1990 350 with a converter/charger on board. The manual says the charger puts out 35 amps for charging and the converter 20 amps for operating all 12 volt acces. Am I correct that when the converter/charger is operating all 12 volt acces are being supplied by the converter and not the battery bank? And the charger is charging the batteries with no draw down from the 12 volt acces.
 
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