2 chargers on same battery a no no ?

Raider Ronnie

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In my ongoing quest for learning this boat and all the systems I find out the Xantrex 3 bank 60 amp battery charger is junk.
Not only does the boat have this Xantrex charger it has a Heart Interface Freedom Combi inverter/charger 10
its 1000 watt ac & 50 amp dc charger 1 bank.
Previous owner probably installed the inverter/charger when the boat was built, added the Xantrex 60 amp charger years later.
Xantrex charger is wired to both house & starting battery. The Freedom Combi is wired to the house battery
So both chargers are wired to the house battery.
No idea why he wired both the house. The Freedom Combi is 50 amps.
I know he did tell me one of them gets screwed up if it’s on & you run the generator.
it a no no or ok to run 2 chargers on 1 battery ?

Thanks

PS.
the Xantrex 60 amp 3 bank is junk.
Ordered a new Xantrex 40 amp.

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Cool Boat

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Interesting question. Common sense would tell us to never hook two chargers to one battery but modern electronics have changed too. I put the latest version 2KW/100A Prosine-Xantrex on the trawler about a year ago. With the previous Prosine we would use the dash control switch to shut off the charger function if the main propulsion engine was running and the Balmar high output alternator was spinning. (genset was always running for other loads) Failure to turn it off would confuse the Balmar programmable voltage regulator and the alternator would actually stop producing/shut down. We would lose the tachometer signal to the pilothouse. I spoke to one of the Prosine factory electrical specialists who noted that the newest version actually sees the other device and shuts itself down. It seems to work fine and we have not lost the tach feed as of now. In your case I would believe that the two chargers continually fight each other or one just dominates the other one. Testing the DC amps on each line would indicate exactly what is going on with yours. 800-446-6180 is the Xantrex number I have in my phone from the last time I called them. Never hurts to ask the designers. Let us know what you find out.
 

Raider Ronnie

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Interesting question. Common sense would tell us to never hook two chargers to one battery but modern electronics have changed too. I put the latest version 2KW/100A Prosine-Xantrex on the trawler about a year ago. With the previous Prosine we would use the dash control switch to shut off the charger function if the main propulsion engine was running and the Balmar high output alternator was spinning. (genset was always running for other loads) Failure to turn it off would confuse the Balmar programmable voltage regulator and the alternator would actually stop producing/shut down. We would lose the tachometer signal to the pilothouse. I spoke to one of the Prosine factory electrical specialists who noted that the newest version actually sees the other device and shuts itself down. It seems to work fine and we have not lost the tach feed as of now. In your case I would believe that the two chargers continually fight each other or one just dominates the other one. Testing the DC amps on each line would indicate exactly what is going on with yours. 800-446-6180 is the Xantrex number I have in my phone from the last time I called them. Never hurts to ask the designers. Let us know what you find out.

I know the newer chargers are designed with safeguards to shut down as to not over charge & when multiple banks are connected it adjunct the charge amp output to the weaker battery.
The newer chargers are newer technology with modified Sine & pure Sine technology.
Doubtful the older changer/inverter had the built in safeguards. It has a remote control panel (actually both units have remote control panels) to monitor & shit it off.
 

ARC

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Most new chargers are smart chargers. They look for feedback to determine their output. For instance a 12v battery resting at 11.9v will tell the charger to go full output and bring back up the voltage. As the stored voltage in the battery increases the charger will back off so not to cook the Battery. So if you have the same low voltage in the battery and you turn on charger #1 it will go up to 14.6v. Now you turn on charger#2 . It sees 14.6 volts so it stays at ready thinking the battery is full. The chargers are getting confused and may not even charge properly. The good side is you will not have a fire or do damage But your battery may not last long.
 

leaky

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Old post but my .02...

I dislike "Inverter/Charger" units. Basically they create too many head scratchers; one is an inverter I want to cut off from the power source when not in use (ie for sure at the dock), a charger I think should remain connected all the time. Then there are questions about how a generator is handled, how to protect circuits, how multiple house batteries are handled etc etc.

I've had one of those Freedom units & the manual in my hand and they are or at least were very high end, but WTF went through my head a bit - nevermind the size & weight...

Anyway, original question, agree with others - 2 chargers potentially switch on/off constantly trying to figure out battery state. Modern chargers are built so if they have multiple banks that get combined they basically channel all the capacity through a single bank automatically, but that is all happening within a single charger.
 

Cool Boat

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Leaky had a good point about what can break. One time the bypass relay on my inverter charger quit. I couldn't feed dock or genset power to the fridge and freezer. Had to wire in a quick bypass until the unit was repaired (under warranty). I note that the replacement unit went another 15 or so years until the capacitors died. Always have a plan B.
 

RCLS2016

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Ronny, 3-4 years ago, I installed a Xantrex truecharge on a customers boat because it fit the requirements and at a good price. Never will I use them again. I measured 1.6VDC from the bonding & ground to the water with a silver chloride lead once it was connected. Their engineer was accommodating and customer service was good with replacing the charger but the new one had issues as well..I would use them for a camper but not a boat... Please keep an eye on your zincs sir and consider looking at the Blue Sea line of chargers if you have 3 banks or less please.
 
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