Xantrex Battery Charger Overheating - Frigoboat Fridge

[motion30]

Originally Posted by bob_77903

I have a Xantrex TrueCharge2, and a AB cold machine with Danfoss compressor. I have had no problems with the charger at all. The cooling fan runs fine. Only time I see the red temp light flashing is if I try to charge in the cold battery temp setting on a very hot day. When its set in the warm or hot battery mode, it functions fine. I suppose the naysayers here would want me to throw the Xantrex overboard and get an Iota. Haven't had any problems with the Xantrex, if I ever do I'll consider that option.

No we would never want you to throw your xantrex overboard but as a former frustrated owner of a true charge maybe you could put it on display as one of the few working examples

[bob_77903]

[Sailormannn]

Originally Posted by bob_77903

I have a Xantrex TrueCharge2, and a AB cold machine with Danfoss compressor. I have had no problems with the charger at all. The cooling fan runs fine. Only time I see the red temp light flashing is if I try to charge in the cold battery temp setting on a very hot day. When its set in the warm or hot battery mode, it functions fine. I suppose the naysayers here would want me to throw the Xantrex overboard and get an Iota. Haven't had any problems with the Xantrex, if I ever do I'll consider that option.

Is yours a 20a or 40a. If you leave just the refrigerator on does the fan eventually come on to cool the unit? In my case, the charger eventually warms to the point where the fan should come on but some some reason it doesn't and the unit signals it's overheating. The only way I can get the fan to come on is if I load it up by turning lights on, etc as described above.

[Sailormannn]

Originally Posted by Captain Bill

The way I see it we have 3 working theories here. The first is that feedback from the fridge controller is causing the overheating. The second, that there is a firmware glitch that stops the fan from running in float mode. The third is that the unit is actually drawing much more power for brief instances that it is actually indicating causing the overheating. S/V Jedi, I would agree with your assessment that the low power draw from the fridge could not be causing a 40a charger to overheat, that is if it was being properly cooled. If the fan is not coming on, then it might be possible for the components to overheat. I think your assessment of a firmware error is the likely culprit, though I would call it a design error. My guess is that Xantrex tried to save a few cents per unit by not putting an actual temperature sensor in the unit, but deciding by some firmware algorithm that the fan needs to come on. I would guess that the designers never thought about the pulsed draw requirements of the danfoss controller. Why would this be? If one looks at the instructions accompanying most refrigeration units it says to connect the unit on a separate circuit directly to the battery. This allows the battery to filter the pulsed requirements and reduces feedback to other electronics. So we know that this fridge is not on a separate circuit, so why is it feeding back into the battery charger. I am beginning to wonder how the battery charger is hooked up. All of my charging sources connect to their own set of cables, through my pathfinder and then to the batteries. The power to the DC buss comes off the batteries through a separate set of cables, so the battery sits between the chargers and any loads. Is this the case in this instance or does the charger connect to the DC buss along with all the loads so the charger is exposed to the noise and pulsed draw of the fridge without the battery being in between? I doubt that the noise/feedback from the fridge is actually causing the overheating but It would make some sense that the pulsed nature of the fridges draw and the pulse width modulation of the charger might be fooling the firmware on the charger into deciding that the load was not enough to require the fan to cool the components. I think the idea of a test running directly from is a good one. I would guess all of this is a result of Xantrex trying to cut out a few components and do everything in software.

Just a couple of points here:

1. I can confirm that the fan will come on in "float" if I turn the lights on with or without the refrigerator on as long as there is a load. It won't come on with just the refrigerator on by itself. Sure seems to be something to do with the refrigerator wiring.

2. When the warning light is displayed the charger definitely feels "warm" but the fan doesn't come on unless I increase the load by turning other accessaries like the lights on. When I do that the fan comes on and the Xantrex cools.

3. Having a marine electrician inspect the wiring on my boat and do some diagnostics is the next step for me.

[bob_77903]

Originally Posted by Sailormannn

Is yours a 20a or 40a. If you leave just the refrigerator on does the fan eventually come on to cool the unit? In my case, the charger eventually warms to the point where the fan should come on but some some reason it doesn't and the unit signals it's overheating. The only way I can get the fan to come on is if I load it up by turning lights on, etc as described above.

Mine is a 20A. And yes, with just the refrigerator on, the cooling fan does come on and cool the unit.

[twistedtree]

Ahh, I have a revised theory. Someone suggested that to save cost Xantrex might not use a temp sensor, but rather use some software algorithm to decide when to turn on the fan. The fan runs with resistive loads, but doesn't run with the fridge load even though they are more or less equivalent power.

If this hypothetical software algorithm is sampling current and using that to control the fan, and the fridge's load comes in spikes, the sampling software might be missing the spikes and be fooled into thinking there is much less load than there actually is. The spike loads heat the charger, but the sampler know it's happening.

[Sailormannn]

Originally Posted by twistedtree

Ahh, I have a revised theory. Someone suggested that to save cost Xantrex might not use a temp sensor, but rather use some software algorithm to decide when to turn on the fan. The fan runs with resistive loads, but doesn't run with the fridge load even though they are more or less equivalent power.

If this hypothetical software algorithm is sampling current and using that to control the fan, and the fridge's load comes in spikes, the sampling software might be missing the spikes and be fooled into thinking there is much less load than there actually is. The spike loads heat the charger, but the sampler know it's happening.

Interesting. But how do we explain that on some boats ... maybe most ... that the Xantrex chargers work. I'm still thinking this must have to do with the wiring in my boat. With my previous charger ( a Cristec) I didn't have any problems with the charger overheating but it fried 2 sets of battaries. I'm wondering if this refrigerator wiring issue is somehow related so worth having this checked out by someone who specializes in boat electrics.

[twistedtree]

Originally Posted by Sailormannn

Interesting. But how do we explain that on some boats ... maybe most ... that the Xantrex chargers work. I'm still thinking this must have to do with the wiring in my boat. With my previous charger ( a Cristec) I didn't have any problems with the charger overheating but it fried 2 sets of battaries. I'm wondering if this refrigerator wiring issue is somehow related so worth having this checked out by someone who specializes in boat electrics.

I'm not sure. There's a lot of poking in the dark here, and making up crazy theories (guilty!). I still think doing the direct-wire-the-fridge-to-the-battery experiment is the next logical step. Hopefully your electrical guy can try that to see if it makes a difference.

As for toasting batteries with your previous charger, I think that's a classic problem where chargers don't go to float until they see charge current drop to a certain level. With a load on, that current threshold is never hit and the charger stays in absorb mode until some timer trips. That can often be 6 hrs or so, and can turn into a lot of overcharging pretty quickly. I don't think the Xantrex will be any less susceptible to that, though it may have a shorter timer. Come to think of it, the one time I had my old boat on shore power and had the fridge running, the charger never went to float, the batteries out-gassed, and my CO alarm went off. It was a 40A Xantrex, just like yours.

Whatever charger you end up with, I'd suggest monitoring it carefully while charging with DC loads on to be sure it's going to float in a reasonable time. Also check the various programming options on the charger to be sure it's set properly for your batteries. You may want to adjust the absorb timers (assuming it's adjustable) to prevent overcharging. As a last resort, many chargers have a constant voltage charge mode which works much like your engine charge system and just puts out a steady 13.6 volts or so. It will take longer to charge that way, but will be immune to loads.

[s/v Jedi]

It might well be the difference between a resistive and a capacitive load. I don't really care because these units are obviously flawed anyway. The microcontroller might not have had enough analog inputs so they had to scrap a $0.50 NTC temp sensor. in the design.

You can try different cabling to your fridge until you drop, but as long as the fridge works correctly, it's not gonna fix a problem with the charger. It's also simpler to test with a capacitor at the fridge connection instead (easy to find in car hifi shops). These would also filter all noise just like the batteries would. But it won't fix the charger anyway.

If you guys decide to replace, you should also have a look at Victron... it's the other end of the spectrum, high quality (and more $$$).

ciao!
Nick.

[Sailormannn]

Originally Posted by s/v Jedi

It might well be the difference between a resistive and a capacitive load. I don't really care because these units are obviously flawed anyway. The microcontroller might not have had enough analog inputs so they had to scrap a $0.50 NTC temp sensor. in the design.

You can try different cabling to your fridge until you drop, but as long as the fridge works correctly, it's not gonna fix a problem with the charger. It's also simpler to test with a capacitor at the fridge connection instead (easy to find in car hifi shops). These would also filter all noise just like the batteries would. But it won't fix the charger anyway.

If you guys decide to replace, you should also have a look at Victron... it's the other end of the spectrum, high quality (and more $$$).

ciao!
Nick.

Anyone here have experience with MasterVolt or ProMariner chargers?

[Stu Jackson]

Yes, ProMariner are to be avoided. 14 years of C34 owner feedback. Not to be trusted. You already have good recommendations for Iota chargers. And Tripp Lite, although I know they make combined I/Cs, maybe not just chargers.

One ? - does your second or third Xantrex fan blow down or up into the unit. I don't think you said. If the "new" one is still blowing the wrong way, what do you think?

I've read your post on co.com and this whole one, and can't, for the life of me, figure out why you keep banging your head against the wall.

Xantrex has been recently proven to be less than useless. You have a relatively new boat with reasonably good wiring and you've worked hard to fix that. Xantrex has become the, if not one of the, worst manufacturers of marine equipment known to man. All in short order, over the course of less than three years. Disappointing, at best. Tragic...

Over 40 years of basic A/B refrigeration proves that Danfoss compressors work pretty much in all boats, even ones with old ferroresonant chargers. Lots of the suppositions about voltages, ripples and the like on this post have been truly fascinating, but not much real in the real world.

If I may? Dump that POS charger and stop wasting your time.

You've learned a lot about your boat and its wiring. Good for you. Time to move on...

[twistedtree]

My current boat came equipped with MasterVolt gear - both an 80A charger and an Inverter/Charger. They work fine, though the Inverter developed an odd problem where it wouldn't always auto-start when shore power was applied, but I talked the problem through with their tech support and they replaced the unit. It was 2 years old at the time. The replacement unit is working fine. This is my first experience with MasterVolt, but so far I'm happy.

Iota was mentioned as a quality charger, and I've also head good things about Charles Marine, though I've never owned either personally.

[downunder]

Best reputation - Vitron

Worst reputation - Xantrex

[adrac]

Originally Posted by Sailormannn

Hi there .. I'm having an electrical problem with a Xantrex TrueCharge2 40A battery charger and Frigomatic Madrid 35F refrigerator.

When we run the refrigerator when the charger is on shore power, the charger shows a temperature fault indicating the charger is overheating. The charger seems to be working fine other wise. The charger fan is working properly and I have tried running the charger under load with all lights and accessaries running except the refrigerator and it works fine.

However; when we turn on the refrigerator, with nothing else running, in about 30 mins we get the fault light on the charger indicating its overheating. This only happens when the refrigerator is running.

The refrigerator seems to work ok when it's powered on as the compressor is running and cooling. I wonder if the electronics in the refrigerator might be interfering with the charger.

Any suggestions would be appreciated.

This will be my last post on this modern marvel of engineering.

My observations (on my own Unit) indicate that the charger only overheats putting out minimal amperage in float mode You really need to load it up which causes the fan to kick on (I believe above 20% of the chargers rated output of 40 amps) Since Im at the dock when I run the charger the draw is minimal well under 10 amps or less than 25% of its output. Fridge draws 3-5 amps, I have led lights and two low amperage fans Obviously No instruments, gps nav lights auto pilot are run when your on shore power. By increasing the output by either manually switching the battery temp to cold or running an equalization cycle the charger is programmed to turn the fan on because the output is increased to 20% or more of the 40 rated amps. I also noticed that by manually switching the battery temp to cold on the charger the charger never drops to less than 20% of its output in float mode even when you shut everything DC off....So its frying the batteries... When you run it in two stage charging mode the fan and charger appears to work mind you the voltage of the batteries need to drop below 12.5 volts to begin charging and the output would be well over 20% of its capacity. As for the people who claim the 20 amp charger fan works well I wouldn't be surprised if xantrex uses the same program and if you turned off your refer and drew lets say 10% of its output (2 amps), see if the fan works and the thing over heats.. In summary my theory,as stated by another member is the charger does not use a temp sensor but a faulty computer program and only kicks on the fan when a certain amperage and or increased voltage is supplied to the batteries and has nothing to with the actual temp of the charger until the faults, warnings are tripped and there is no connection between the fan control and the when the charger overheats because the fan should turn on and it doesn't..

ON a positive note Im glad I found this forum searching for answers on my battery charger dilemma. I read a about a lot of interesting and informative posts on a wide variety of subjects I often wondered or thought about...

[Sailormannn]

Originally Posted by adrac

This will be my last post on this modern marvel of engineering.

My observations (on my own Unit) indicate that the charger only overheats putting out minimal amperage in float mode You really need to load it up which causes the fan to kick on (I believe above 20% of the chargers rated output of 40 amps) Since Im at the dock when I run the charger the draw is minimal well under 10 amps or less than 25% of its output. Fridge draws 3-5 amps, I have led lights and two low amperage fans Obviously No instruments, gps nav lights auto pilot are run when your on shore power. By increasing the output by either manually switching the battery temp to cold or running an equalization cycle the charger is programmed to turn the fan on because the output is increased to 20% or more of the 40 rated amps. I also noticed that by manually switching the battery temp to cold on the charger the charger never drops to less than 20% of its output in float mode even when you shut everything DC off....So its frying the batteries... When you run it in two stage charging mode the fan and charger appears to work mind you the voltage of the batteries need to drop below 12.5 volts to begin charging and the output would be well over 20% of its capacity. As for the people who claim the 20 amp charger fan works well I wouldn't be surprised if xantrex uses the same program and if you turned off your refer and drew lets say 10% of its output (2 amps), see if the fan works and the thing over heats.. In summary my theory,as stated by another member is the charger does not use a temp sensor but a faulty computer program and only kicks on the fan when a certain amperage and or increased voltage is supplied to the batteries and has nothing to with the actual temp of the charger until the faults, warnings are tripped and there is no connection between the fan control and the when the charger overheats because the fan should turn on and it doesn't..

ON a positive note Im glad I found this forum searching for answers on my battery charger dilemma. I read a about a lot of interesting and informative posts on a wide variety of subjects I often wondered or thought about...

Have you experimented with turning the output amperage down to see if that makes any difference.