House batts not charged by alternator

[Edward Buker]

Bill, Terry,

It also does not help that the alternator in a rear diesel pusher configuration has poor air flow over it ,no normal front radiator fan air wash, and is usually mounted near the turbocharger. There is also a circuit within the alternator regulator that de-rates the current output if the alternator is getting hot. Our alternators have some tough duty so we need to lighten the load to compensate if the house batteries are down as Bill mentioned.

I was reading numbers like 11 amps on some of the energy star Samsung units. That would be 110amps or so on an inverter at 12V when the compressor is running. Maybe that is starting current but I doubt that.  The current would likely be much higher momentarily until the compressor is started. Has anyone actually measured one of these Samsung frig units with the compressor on for current load, AC amps, and then DC amps using the inverter?

Later Ed

[Paul Schwalen]

[size=14][/size]Ed,

This past April I had a Samsung RF197ACRS installed in our 03 Contessa.  Upon returning home I plugged the RV in and waited until the next morning when I unplugged all the electronics that usually draw amps (TV, DVR, Sony system,Microwave) and then switched on the inverter and turned the pedestal power off.  I was not smart enough to note the voltage at the batteries or at the Aladdin at this point but did later realize that error and then noted the voltage at the Alladin and at the batteries every hour for the rest of my test.  After 3 hours the voltage was 12.5V at the Alladin, after 4 hours it was still 12.5V at the Aladdin and 12.57V at the battery posts.  After 8 hours the voltage at the Alladin was 12.3V and 12.41V at the batteries.

I should note that the batteries were only7 months old when I did the test.  I felt that after 8 hours of draw from the Samsung it seemed to me that I would not have a problem with my inverter and would not have to run the generator just to keep the refer from depleting my house batteries while I was on the road.  I did spend some time trying to find the amperage draw from Samsung online and at some point I did find a 3.9A draw at initial startup of the refer but I don't remember where I got that number from.  On the puny manual that Samsung provides with the refer they do not mention amp draw anywhere.

Since that time we have done a fair amount of driving and only run the genny when we need to keep the RV cool by running the roof AC's.  We have not boondocked at a Walmart yet but feel that it will not be a problem if we charge the batteries before retiring for the night with the genny.

Hope this helps.

Paul

[Edward Buker]

Paul,

The saving grace with a well insulated frig, cold food and frozen goods, is that the compressor does not have to run that often and that long. It would still be good to know what AC current the unit draws. If you have an AC current readout you can get that number watching the AC current offset on your monitor system when the compressor runs. Open the door until it comes on. May be 4 amps of background draw that then goes to 12 amps for instance which then would be 8amps AC for the frig. Multiply that by current by 10 or 11 with losses and you have the approximate DC battery/alternator current the inverter needs to be supplied with to run the frig.

Later Ed

[Paul Schwalen]

[size=9][/size]Ed,

Unfortunately my Aladdin does not have a readout for AC amps.  I will try to isolate the wires for the refer where they connect at the breaker box and use an AC amp meter to determine the amp draw.

Paul

[Edward Buker]

Paul,

This is just information for those looking at converting to an electric fridge option. This is truly a back burner item when it best fits your plans. I know there are better times to be had traveling and having some fun.

When and if you get to it.....If you have an amp clamp meter you can get a reading with a line splitter like this one at the fridge plug or just with the clamp directly around a breaker wire.

http://www.amazon.com/Extech-480172-AC-Line-Splitter/dp/B0000YHN9W

If your Alladin has DC amps you could use that measurement directly to see what the fridge compressor uses while using the inverter.

Later Ed

[Paul Schwalen]

[size=14][/size]Ed,

Thanks for that info, I did not know that a line splitter device existed!   Since my Aladdin does show battery volts and amps perhaps I can get the needed amp draw information by disconnecting everything that would be drawing amps, covering the solar panel and turn the pedestal breaker off before switching the inverter on, then open the refer door and wait for the compressor to cut in.  

We are not home, but when we do arrive I will try and get the needed amp draw and post it.

Paul

[Edward Buker]

Paul,

That will work, covering the solar panel is probably over kill. Maybe just do the test towards evening or on a cloudy day when the output is minimal. It does not produce that many amps anyway.

Later Ed

[Terry Melot]

Well, the alternator kept the house batts right up to close to 14v all day in the trip from Vegas to Phx. The Samsung data plate says it uses 3.9 amps.
So the frig was not the problem.  Probably a loose wire somewhere, who knows.
Bill, thanks for suggestions. I'll certainly remember to charge the batteries with the gen after dry camping.

[Gerald Farris]

Terry,
An intermittent inoperative condition with the "Bird" system is not terrible uncommon. The problem is that it is almost impossible to diagnose the problem with the system if it is working at the time you check it. However, if you continue to have the problem, you are going to need to fix it.

Gerald    

[Michael Marcocchio]

Hello Terry, Michael here, I had a problem like yours as the BIRD was not charging the house batteries while driving I installed a new BIRD and now the alt charges the house batteries while driving

[Terry Melot]

Thanks, Mike. It worked on the last trip. Glad to know that's the most likely culprit.  I may pick up a spare Bird and carry it with me.