Xantrex Battery Charger Overheating - Frigoboat Fridge

[Sailormannn]

Thanks Richard. I have that one figured out. Actually there is a reverse polarity warning light on the Xantrex charger. That one is off. Any other suggestions welcomed.

[Richard Kollmann]

In order for that refrigerator fuse to blow the problem of amperage overload would seem to be in that circuit. What other items of DC power do not work with buss wire fuse removed? If fuse is good and battery charger 110 volt power is disconnected will refrigerator run or blow another fuse?

[Sailormannn]

The fuse blew when I was taking some voltage readings on the connections at the refrigerator. The connections are very close together so i probably caused the short. With the new fuse in it runs fine, just the temp warning at the charger comes on after it's been running for a while.

[motion30]

I had a truecharge 40amp It ran ok for a while then went crazy, would not cycle to float unless switched off then back on It killed a $600 agm battery I changed to Iota and have been happy No problem running a 12v fridge either on or off shore power I would suspect the true charge Your experience with xantrex support is about what I would expect from my experience. Sorry I could offer no help

[Sailormannn]

I hear you. I'm beginning to wonder about this charger. I might try moving the charger and mount horizontally so there's more air flow. The way it's mounted is well within spec but I'm wondering if it needs more clearance above for air flow. The fan intake is on the bottom and warm air exits on the top of the unit. Letting the warm air disperse in a larger area might make sense.

[Sailormannn]

Here's the latest on my woes with the Xantrex Charger


Took a series of voltage and amp tests at the batteries and refrigerator today with charger on and off. Nothing untoward found. All readings to me appeared normal. The refrigerator when it starts draws 3.5A at both the batteries and at the refrigerator. It drops to 2.8A when it's been running for a while. Voltage with the charger on was 13.3v at the batteries and 13.2 at the refrigerator. With the charger off amps were the same and voltage was 12.9 at the batteries and 12.6v at the refrigerator. With the refrigerator off voltage was 13.1v at the batteries and 12.7v at the refrigerator.

1. My focus is shifting back to the charger itself. It's mounted on the side of the boat by the stern near the transom. See the pic attached. It is an enclosed area at the back of the boat and there is lots of clearance above and under the charger. While there is a lot of volume in the area, it isn't ventilated per se and I'm wondering if that is the problem. It takes 30 mins or so for the unit to overheat so I'm wondering if the fact the warm air exiting the charger has no where to escape that it eventually builds in the area and causes the unit to overheat.
2. The fan on the charger does come on however one thing that is very odd is that when the warning light comes on indicating the unit is overheating, the fan shuts off. Unfortunately Xantrex Support didn't know if this was normal. Hard to imagine it is, but that's a mystery.
3. Since the unit is sitting in the back of the boat by the tramsom I'm wondering if the fact that this area doesn't have ventilation is the problem and if anyone has any experience with this.
4. The entrance to the area is at the back of the sleeping berth. There's an access hatch, but no ventilation grills or anything.

Any suggestions would be appreciated including ideas on adding ventilation to the area; what would be the best way to do that without compromising waterproof integrity of the cockpit; adding a fan, etc.

[DeepFrz]

Is the fan blowing in the right direction?

# The fan on the charger does come on however one thing that is very odd is that when the warning light comes on indicating the unit is overheating, the fan shuts off. Unfortunately Xantrex Support didn't know if this was normal. Hard to imagine it is, but that's a mystery.

I'm having trouble getting my little mind around this...

[Sailormannn]

When the fan is on, the warm air exits at the bottom of the unit. When the high temp warning light is flashing indicating the unit is overheating the fan isn't running. Weird.

Xantrex support couldn't confirm to me if this was "normal". If you've read all the posts above you'll note this is a replacement unit. The unit was installed by an experienced installer who does these all the time. He's at a loss to figure this out too.

[senormechanico]

Originally Posted by Sailormannn

Here's the latest on my woes with the Xantrex Charger

1. The entrance to the area is at the back of the sleeping berth. There's an access hatch, but no ventilation grills or anything.

Any suggestions would be appreciated including ideas on adding ventilation to the area; what would be the best way to do that without compromising waterproof integrity of the cockpit; adding a fan, etc.

Try just leaving the entrance hatch open.
That should give you enough air exchange to see if ventilation is the problem.
A zero cost and effort test.

[Lancerbye]

After reading through this thread I have to admit that you have a unique problem. I also have a Xantrex 40 truecharge plus. Mine looks a lot different from yours.It has the cooling fins up the sides which create a chimminey effect to help cool the components that create heat when loaded. This one has to be vertically mounted. I live aboard 6plus months a year during which the fridge also using a DF350 24/7. Five plus years on the same wet cell Golf cart batteries without problems. The cooling fan will only come on when the unit is bulk charging or I am drawing more then 10 amps for a while. The high temp indicator has never come on. I wonder if the newer units have a basic problem. The idea of the temp light coming on before the fan is wrong. Either a faulty unit or bad engineering. I have noticed mine will try to bulk charge causing the fan to come on if there is a bad connection at either the batteries or the charger. If the charger does not see the true battery voltage it will missbehave.

[DeepFrz]

The fan should always blow so that the hot air exits the top of the unit, at least in any power supply/charger I have ever seen.

The airflow direction may be your problem.

The reason I asked which way the fan was blowing is because I once flew into a city to work on a power supply overheating problem. The local tech had replaced the fan at the top of the supply, and had installed it so the fan was blowing down. There was also a fan at the bottom of the supply blowing up. There were no vents in the middle of the supply.

Why the fan would shut off when the overheat light comes on is beyond me...

[Sailormannn]

Originally Posted by Lancerbye

After reading through this thread I have to admit that you have a unique problem. I also have a Xantrex 40 truecharge plus. Mine looks a lot different from yours.It has the cooling fins up the sides which create a chimminey effect to help cool the components that create heat when loaded. This one has to be vertically mounted. I live aboard 6plus months a year during which the fridge also using a DF350 24/7. Five plus years on the same wet cell Golf cart batteries without problems. The cooling fan will only come on when the unit is bulk charging or I am drawing more then 10 amps for a while. The high temp indicator has never come on. I wonder if the newer units have a basic problem. The idea of the temp light coming on before the fan is wrong. Either a faulty unit or bad engineering. I have noticed mine will try to bulk charge causing the fan to come on if there is a bad connection at either the batteries or the charger. If the charger does not see the true battery voltage it will missbehave.

What's a bit weird with my unit is the fan not running when the charger temp warning lights are flashing. I've sent another note to Xantrex asking them to advise if this is normal. If it is, there's problem with the engineering. If not I have another bad unit which doesn't inspire a lot of confidence in Xantrex.

All the connections at the batteries and charger have been redone; although I'm using the same wires. The boat is only 7 years old so the wiring is in good shape. The mystery continues. I'm going to run it for a while with the hatch open and see if that makes a difference.

[Sailormannn]

Originally Posted by DeepFrz

The fan should always blow so that the hot air exits the top of the unit, at least in any power supply/charger I have ever seen.

The airflow direction may be your problem.

The reason I asked which way the fan was blowing is because I once flew into a city to work on a power supply overheating problem. The local tech had replaced the fan at the top of the supply, and had installed it so the fan was blowing down. There was also a fan at the bottom of the supply blowing up. There were no vents in the middle of the supply.

Why the fan would shut off when the overheat light comes on is beyond me...

I'll follow this up with Xantrex. In the manual they describe the vent at the bottom of the charger as the "Air Intake Vent". On my unit, hot air is coming out of the bottom when the fan is on, suggesting the fan isn't blowing in the right direction.

[DeepFrz]

It doesn't make any sense to design a unit where the fan is fighting the natural flow of convection. I think your fan is installed so it is blowing in the wrong direction.

[DeepFrz]

I just looked at the installation manual and see that it can be mounted in any orientation, however, the two vertical directions are not permitted/suggested for marine use unless there is a further drip shield. Now, the location you have is pretty sheltered so I don't think that is a problem. However, I don't think mounting it so that the fan has to work against normal flow of convection makes any sense at all. Perhaps that is why the other poster had better luck when he changed the mounting orientation. Just my thoughts on this. Good luck.