Xantrex Battery Charger Overheating - Frigoboat Fridge

[btrayfors]

The frig should not make any difference....a 3A draw is nothing.

First thing you might do is borrow or buy a clamp-on ammeter and see what current draw you're getting, and what charging current is on the batteries.

The frig would have to be drawing more than ten times its designed draw in order to overload a 40A charger. Highly unlikely unless the compressor rotor is frozen. But a clamp-on ammeter will tell you quickly what's going on.

A good quality multimeter will tell you if the voltages are correct.

How do you know the batteries were being overcharged? Oddysey batteries are AGMs and can take a LOT of amperage. Matter of fact, AGM batteries can burn out alternators if they're not properly regulated (because they draw so much amperage for so long) and could even stress a small battery charger.

The remote indicator might or might not be accurate. Use a good multimeter directly on the batteries to measure voltage.

Bill

[Sailormannn]

Originally Posted by btrayfors

The frig should not make any difference....a 3A draw is nothing.

First thing you might do is borrow or buy a clamp-on ammeter and see what current draw you're getting, and what charging current is on the batteries.

The frig would have to be drawing more than ten times its designed draw in order to overload a 40A charger. Highly unlikely unless the compressor rotor is frozen. But a clamp-on ammeter will tell you quickly what's going on.

A good quality multimeter will tell you if the voltages are correct.

How do you know the batteries were being overcharged? Oddysey batteries are AGMs and can take a LOT of amperage. Matter of fact, AGM batteries can burn out alternators if they're not properly regulated (because they draw so much amperage for so long) and could even stress a small battery charger.

The remote indicator might or might not be accurate. Use a good multimeter directly on the batteries to measure voltage.

Bill

Thanks Bill .. I have replaced the batteries on the boat twice now. The original batteries were wet cells and the batteries vented spilling acid into the battery compartment. Tests we did at the time suggested the charger was working ok so we attributed the problem to faulty battery cells. I replaced these with AGMs 4 years ago and noticed this spring that they were venting again when the boat was left of shore power with the refrigerator on. We replaced with the Xantrex charger and 3 new Odyssey group 34 batteries. Now I'm getting the warning light on the charger. Thought the charger might be defective and got a new one, which is showing the same fault. Don't think the draw from the fridge is a problem by itself as charger only shows a 20% draw with the fridge on; never any more. But after 30 mins or so the warning lights start to flash; draw still shows 20%. The only time they flash is when the fridge is turned on, so it has to be something with the fridge that is causing the problem, but I'm at a loss to figure out what the problem is. I guess the next step is to do the tests as suggested. If anyone has other ideas, please let me know

[Seahunter]

Call Xantrec support, they'll guide you through a reset and a fault test. Watch for input and output voltage settings as they guide you through the test; it sounds like you have a connection issue. It's not uncommon to have voltage at your meter with a burned connection, but there will be NO amperage resulting in a faulty overheating error. I've seen many times where there is a burned terminal (still touching) giving a voltage reading, but there's not enough meat left to allow any amperage to get get through. A multi-meter is not enough; you'll also need a clamp-on ammeter.

[Seahunter]

Here's whats happening. Even though there's voltage showing at the charger, there's a connection fault in the AC system. The batteries' voltage begins to drop as excessive load is added and the charge can't keep up (because it's not getting the correct amperage to actually charge). As the voltage drops the Xantrex's indicators come on, indicating a charging fault and begins to overheat. Here's a simple trick; if you have a genset, remove yourself from shore power, start the genset making sure the system is set to "ship" allowing the charger and inverter another source. If there's a shore power connection issue, the charger issues will disappear after a hard reset. If the connection issue is after the shore power AND the genset, IE but before the Xantrex, you'll still have an issue, but you'll now know where to look.

[Sailormannn]

Originally Posted by Seahunter

Here's whats happening. Even though there's voltage showing at the charger, there's a connection fault in the AC system. The batteries' voltage begins to drop as excessive load is added and the charge can't keep up (because it's not getting the correct amperage to actually charge). As the voltage drops the Xantrex's indicators come on, indicating a charging fault and begins to overheat. Here's a simple trick; if you have a genset, remove yourself from shore power, start the genset making sure the system is set to "ship" allowing the charger and inverter another source. If there's a shore power connection issue, the charger issues will disappear after a hard reset. If the connection issue is after the shore power AND the genset, IE but before the Xantrex, you'll still have an issue, but you'll now know where to look.

Seahunter. Setup on this boat is very simple. No genset or solarcells or anything .. just 3 batteries and a Xantrex charger. The problem only occurs when the 12v refrigerator is turned on when the charger is plugged into AC and on. If the problem is on the AC side, why wouldn't this happen when I load it up with lights and other accessories are turned on and the draw is higher. I'm thinking this must have something to do with the refrigerator.

[Seahunter]

Actually, this indicates it's in the SP circuit and that it's a connection issue. A fridge is all about amperage; I doubt if you turn on every light in you're boat if it would add up to even 1/2 the start-up amperage of the fridge. Check voltage and amperage, starting at the SP. I've seen where the breaker or voltage coming to your dock box is defective. For test purposes use somebody else's SP. If there's a problem with the plug the plug will show signs of discoloring or burning. My guess is that it's after the SP connector on the boat (as it's hard to keep this area dry on many boats) remove the scews and check first if SP and cable is good. Make sure to reseal with non-silicone sealant after test or repair.

[senormechanico]

Originally Posted by Sailormannn

Thanks for the post. The batteries are new Oddysey batteries and showing at full charge on the charger remote panel. The charger shows them accepting the float charge and everything looks fine except when I turn on the fridge. I tried putting all the halogens and accessories on last night and running the charger for an hour to see what would happen. The charger showed a 40% draw and no problems. When I turn on the fridge I get a warning light flashing on the charger (It doesn't shut down; just a warning). The temp light and charger lights flash indicating the unit it overheating.

Strange .. I thought it was the charger, and replaced it, but the new one does exactly the same.

Sounds to me like your charger needs the "Black Tape Update" which is placed over the warning light.
<sarc>

[Sailormannn]

Originally Posted by Seahunter

Actually, this indicates it's in the SP circuit and that it's a connection issue. A fridge is all about amperage; I doubt if you turn on every light in you're boat if it would add up to even 1/2 the start-up amperage of the fridge. Check voltage and amperage, starting at the SP. I've seen where the breaker or voltage coming to your dock box is defective. For test purposes use somebody else's SP. If there's a problem with the plug the plug will show signs of discoloring or burning. My guess is that it's after the SP connector on the boat (as it's hard to keep this area dry on many boats) remove the scews and check first if SP and cable is good. Make sure to reseal with non-silicone sealant after test or repair.

I'll have to test. I did try to plug in to a different outlet on the same service and that didn't make a difference. There are 3 boats plugged in and no-one else is complaining. I'll check the cords again and look at the connections closer.

[TOM]

Could i ask you how your charger is mounted ,is your Xantrax wall mounted or lying flat mounted . We have had 3 Xantrax 40 amp replacements with all the problems you are having . We took it off the wall and mounted it flat on the floor with the required air space underneath ,we have not had a warning light go on since ....Dont ask me why as i have no idea . I know this is a very low tech solution but it is definatly worth trying .

www.byamee.com

[Sailormannn]

Mounted vertically. Hard to believe that would make a difference. Were you getting the warning light with your refrigerator or other accessaries. I just get it with the fridge on.

[Sailormannn]

Originally Posted by Seahunter

Actually, this indicates it's in the SP circuit and that it's a connection issue. A fridge is all about amperage; I doubt if you turn on every light in you're boat if it would add up to even 1/2 the start-up amperage of the fridge. Check voltage and amperage, starting at the SP. I've seen where the breaker or voltage coming to your dock box is defective. For test purposes use somebody else's SP. If there's a problem with the plug the plug will show signs of discoloring or burning. My guess is that it's after the SP connector on the boat (as it's hard to keep this area dry on many boats) remove the scews and check first if SP and cable is good. Make sure to reseal with non-silicone sealant after test or repair.

I will check the shore power connections out .. but one question. If I can connect a heater inside the boat to an AC outlet and it works ok, wouldn't that suggest my AC connections on the shore power side are OK or am I missing something.

[DotDun]

Assuming it's mounted properly.

The Xantrex pulls max 6.5amps on the shorepower (15.5v charge @ 40a = ~620watts @ 80% = 6.5a @ 120v. An electric heater may not be a good test, a resistive heat coil usually doesn't care what voltage you give it.

Check the current the frig is pulling.
Check the current the charger is pulling from the SP.

[Sailormannn]

Yes. It has lots of clearance on all sides so don't think that is an issue. At least 4-5" on all sides.

Would a faulty connection on the AC side cause a charger to put too much voltage into the batteries. That's why I replaced the charger in the first place.

[btrayfors]

No it would not.

I think you're on the wrong track with the AC thing.

Stop playing about and wild guessing.

Get yourself:

1. a good clamp-on ammeter; and
2. a good multimeter.

Then, use them to measure the amperages and voltages.

Then, you'll know.

Bill

[Seahunter]

Originally Posted by Sailormannn

I will check the shore power connections out .. but one question. If I can connect a heater inside the boat to an AC outlet and it works ok, wouldn't that suggest my AC connections on the shore power side are OK or am I missing something.

Marks to Dotsun, a heater isn't a motor driven device, it's based on resistance. It'll work, regardless of voltage but not to it's optimum heat. If you put a clamp-on ammeter on this load you'll see how much it's drawing.