Xantrex Battery Charger Overheating - Frigoboat Fridge

[Richard Kollmann]

Sailorman Yes, you are correct even smart chargers operating in Float mode can cause battery gas venting when these small 12 volt refrigerators run many hours per day. I have been told that the liquid recovery vent caps will reduce liquid loss. Another solution to reduce battery venting is to put a timer on battery charger with several hours of off cycles per day or in warm climates reduce charger float voltage The best solution to reduce battery stress when operating small Danfoss BD35 refrigeration compressors from shore power is to install a 110 volt AC to 24 volt DC converter designed for this purpose. The BD35 will automatically transfer back to 12 volt battery power when AC power is disconnected. These BD35 power converters are available from WAECO and maybe others.

[Seahunter]

Is the "equalize" switch in the on position on the charger? If so turn it off as most AGM's cannot be equalized by 3 stage chargers. It may be trying to equalize automatically.

[Sailormannn]

Equalize is off.

[Seahunter]

Have you called Xantrex support yet? One thing that's important is that the charger be set to battery specs. The cut in and cut out voltages and float must be set according to the battery manufacturer specs and not to the charger's default settings. EG AGM's can demand a higher input up to 16.5VDC on a 12VDC system, the charger may just be choking. There may also be a timing issues with the float.

[motion30]

Richard K
do these refrigerators work better when run on the higher 24v mode?
by that I mean cool down quicker

[Richard Kollmann]

motion30
Registered User


Join Date: Feb 2009
Posts: 617


Re: Xantrex Battery Charger Overheating - Frigoboat Fridge
Richard K
do these refrigerators work better when run on the higher 24v mode?
by that I mean cool down quicker

Re: Xantrex Battery Charger Overheating - Frigoboat Fridge
Richard K
do these refrigerators work better when run on the higher 24v mode?
by that I mean cool down quicker.

Answer: I have run more than one hundred controlled tests on Danfoss BD compressors but none comparing performance of running these compressors on 24 volts My guess is control module might be cooler but compressor performance will not change.

[capn_billl]

When I leave the boat for an extended period of time, I disconnect the house bank and run soley off of the charger. Yes I've come back to a warm fridge sometimes when I lose shore power, but I'd rather do that than come back to a dead house bank. spoiled food is cheaper than batteries. I've thought of a solar cell, or float charger just to keep the batteries topped off, but if I go out and reconnect the batteries for a few hours when I check on the boat they are always topped off.

[DotDun]

Originally Posted by Richard Kollmann

Sailorman Yes, you are correct even smart chargers operating in Float mode can cause battery gas venting when these small 12 volt refrigerators run many hours per day.

Good batteries will not gas at float voltage.

Assuming float voltage is set correctly (13.2-13.4 volts), a good set of fully charged batteries will draw 0 amps (OK, maybe 200ma). Zero amps does not produce gassing. At that point, the charger will pick up the house load, assuming the load is within the charger's capability. If your 12v battery is gassing at float voltage, it's a bad battery.

[Seahunter]

Originally Posted by DotDun

Good batteries will not gas at float voltage.

Assuming float voltage is set correctly (13.2-13.4 volts), a good set of fully charged batteries will draw 0 amps (OK, maybe 200ma). Zero amps does not produce gassing. At that point, the charger will pick up the house load, assuming the load is within the charger's capability. If your 12v battery is gassing at float voltage, it's a bad battery.

Almost no gasing with AGM's.

[TOM]

Originally Posted by 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.

I know it sounds odd .But the minute we mounted ours horizontally all our problems stoped . Mounted it vertically again and overheating lights came back on. I can not give an explanation for this but all i can say is that if all else fails try it.

www.byamee.com

[redcobra]

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.

I ugraded from an old 20A truecharge to a newer 40A truecharge2 and had a lot of similar issues. Got rid of the Truecharge2 and went back to the origianl 20A and the problems went away. Service from the factory was non-existant since it was out of warranty. The best they would do is sell me another one at "cost" (same price you could buy one online.) Claimed that since it is now all just a circuit board it is not feasable to repair. Phooey. No more Xantrex for me.

[Sailormannn]

Originally Posted by DotDun

Good batteries will not gas at float voltage.

Assuming float voltage is set correctly (13.2-13.4 volts), a good set of fully charged batteries will draw 0 amps (OK, maybe 200ma). Zero amps does not produce gassing. At that point, the charger will pick up the house load, assuming the load is within the charger's capability. If your 12v battery is gassing at float voltage, it's a bad battery.

I think what's been happening with my system is that the current draw from the refrigerator is sufficient for the charger to think it needs to drop back into Bulk or Acceptance modes, which drives the system to higher voltage and over-charging the batteries. My boat sits at dock with the shore power on and refrigerator on a lot.

The better solution here might be to install a 110 volt AC to 24 volt DC converter designed for this purpose to the refrigerator to take the stress off the batteries. That doesn't explain why the new Xantrex is throwing off a warning light, but might solve the whole problem. Waiting to hear back from Xantrex if they have any suggestions.

[DotDun]

FWIW, I have the Xantrex XC5012 and run (2) 6a compressors (frig & freezer) while on shorepower with no problems.

It would be interesting if Xantrex will tell you at what point (how many amps) the charger gives up on float and goes back to bulk.

Have you be able to measure the current draw of the frig?

[DotDun]

I guess I should RTFM......

"Finally, in the Float stage, the charger
continues to provide voltage at a lower level to maintain the
battery in a fully charged state. If there is no load on the
battery, it will typically draw very little current. The charger,
however, is able to provide current to its full rating to power
auxiliary DC loads on the battery.

The charger will restart the charging cycle in the Bulk stage if
the lowest battery voltage of the three banks drops below
12.5 V (12 Vdc chargers) or 25 V (24 Vdc chargers) for 15
minutes. After 21 days, the charger will automatically restart
charging in order to refresh the batteries."

[btrayfors]

DotDun,

Glad you did read it :-)

I was just about to post a short note re: smart chargers.

A modern smart charger, faced with a fully charged battery and in the float mode, can deliver a LOT of amperage without dropping back to the absorption or bulk charging modes.

In other words, it is fully capable of powering most/all onboard loads without affecting the voltage being maintained at the house batteries.

Examples:

1. My Iota DLS-45/IQ4 remains in the float mode (13.6V) even when powering my SSB radios and my SG-500 amplifier. The amplifier draws 50A or more during voice peaks in the SSB mode, and the transceiver draws another 30A during peaks. That's 80A or more during voice peaks....the Iota takes that in stride and remains in the float mode.

2. My Victron Multi-Plus charger/inverter easily maintains my onboard refrigeration (which draws 6A and runs much of the time because of its advanced age -- 23 years -- and a large poorly insulated box). In addition, it runs other onboard loads...computer, SSB and VHF radios, nav instruments, TV, etc. all the while remaining in the FLOAT mode.

It's the battery voltage which controls what the smart charger will do, in most instances. Some of the 'smarter' chargers will also take account of battery temperature and length of time at various delivered current.

I almost never disagree with Richard Kollman who is the acknowleged refrigeration expert, but I must take issue with his remark about compressors which run a lot throwing off the charger's calculus. NO, sorry, if this is happening then you've got a lousy charger.

Especially since, as earlier noted, the compressor in question draws only 3A when running.

I note also that we are 45 posts into this vexing but resolvable issue.

PLEASE, Sailorman, get some instruments and MEASURE WHAT'S GOING ON.

Put us out of our misery :-)

Bill