Refrigerator Killing Batteries?

[Namaste]

I have a 2010 R-25 with the Nova Kool refrigerator. The refrigerator drew my old stock batteries down to 9v after two days at anchor and they were unable to hold a charge after that. I figured they were old with a ship date of Aug 09 so I replaced the original dual purpose batteries with Deka DC27s . Now the new batteries still are unable to keep the refrigerator going even when I have the battery charger on continuous shore power and I have everything else on the DC panel shut off. At this point the refrigerator which is set on "4" draws the batteries down to 11v which seems to be too low to keep the refrigerator running so I am losing this race. The refrigerator never really gets cold and the batteries never really hold a charge. The battery charger is the 1220i.

Thoughts, ideas, suggestions?

 

[walldog]

It appears that either your charger is not working properly or your reefer is drawing too much current. Turn the reefer off and see what voltage your batteries come up to with no load. You should see something near 14.

 

[GulfSailor]

At this point the refrigerator which is set on "4" draws the batteries down to 11v which seems to be too low to keep the refrigerator running so I am losing this race. The refrigerator never really gets cold and the batteries never really hold a charge. The battery charger is the 1220i.

The fridge should shut off at around 11v whatever temperature you have it set for.
As Walldog said, it's either the fridge or the charger.
I have the same charger, only a few months old and it's just failed, so it can happen.

However, as the fridge previously drew down the batteries to 9v and it never really gets cold, it does sound like the fridge could be the culprit.

 

[knotflying]

My experience has been that with the refrigerator on without a power source to charge the batteries that the batteries will discharge after a day. I have the solar panel and even with that after 10 hours I can see that the batteries are starting to loose the battle. Walldog may be right with his assumption that it is either the charger or refrigerator and it could be both. When you go on shore power your voltmeter should go to 14 volts within a minute because that is when the charger and relays kick in. One mistake I made once was that even though I was plugged into shore power I forgot to turn on the inverter switch that goes to the battery and therefore the batteries were not getting the charge. Not sure if your system is the same as mine, but check that the switch is on. When trouble shooting troubleshoot one suspected culprit at a time otherwise you could go crazy. I would suggest checking your charging system first to rule that out before you troubleshoot the refrigerator.

 

[Newtugnut]

Another option to consider (but it involves installing a bit of gear first), is to put in a Xantrex Link 10 or their new model Link Lite, which is a battery Amp-hr meter. Switching all loads off, and just having the fridge running, so you can see EXACTLY see how many amps the fridge is drawing. From manufacturer literature one can confirm whether the numbers are high/low or just right. Another factor is the duty cycle, for planning purposes on our boat, I assume the frig is on 50% of the time. With some simple tests considering outside temp etc. you can determine whether this applies to you.

Again turning all loads off, with a fairly depleted battery, The Link Lite will tell you exactly whether the charger (at least initally) is putting out its rated charge. Of course, with multi-stage charging this rate will taper off quickly.

IMHOB battery voltage is not a great indicator of the state of the battery. However, if this is all one has, leaving the battery completely at rest for 24 hrs and useing a digital voltmeter that goes out to two significanty digits will help. there are simple charts on the INTERNET giving battery voltage vs % capacitiy for various voltagers (I forget the actual numbers).

We found the Link to be extremely useful, when staying at anchor in our sailboat over several days running a small portable freezer and a fridge which are the major loads. then running the portable generator to 'catch up when the battery is drained to 50% capacity. Unfortunatley, the laws of physics and batteries hold, it seems to take forever to get those last A-hrs back in the battery.

An A-Hr meter is akin to a "fuel gauge" for your baterry/charger system.

Hope this helps

Dawn-Marie and Frank future Ranger owners (presently owners of a Catalina 36 sailboat)

 

[jroyle]

With our previous boat (4- newer 6volt Trojan house batteries) we would be lucky to get one day of refigerator and occasional house lights from the batteries. With the R-29 and solar panel supplying an average of ~ 7amps we can spend a weekend at Catalina and never dip below 12 volts.

 

[Levitation]

It is relatively simple - only 2 numbers to remember - 12.7 and 12.24
Full charge is 12.7 volts (charger off for at least 4 hours to allow the surface charge to dissipate - if it is still near 13 volts put a small load across the battery for 5 minutes)
50% charge is 12.24 volts (and as low as you want to go if battery life is important to you)

Here is an excellent primer:
http://www.marxrv.com/12volt/12volt.htm

 

[Claud'in]

I am not a specialist but the best way of having batteries in good condition which pass off slowly, it is of always to provoke a small discharge. My tugs is alongside the quay all year and I leave either the refrigerator, that is a small lit heating. It is the advice of my mechanic.
And like this, no problem after a week staying on my anchor.
What do you think about that?
Claude of Claud'in

 

[Levitation]

I think you need a new mechanic...

 

[Jimfrom Gloucester]

Thanks all ! I have left the boat in Florida and am home for the summer. We spent a few days traveling on the boat after this incident with the battery not charging. The new house batteries did not get above 11 v while on shore power in spite of the battery charger's best efforts. When we got underway the batteries dropped even lower. Then at one point I opened the throttle up to make a bridge before it closed and low and behold the batteries charged up in a couple of minutes and remained charged and doing their job for the next two days.

I am figuring there has to be a loose connection somewhere. The boat has been put to bed and I did not find anything while putting her up. Will try again in the winter,

Thanks

 

[walldog]

Thanks all ! I have left the boat in Florida and am home for the summer. We spent a few days traveling on the boat after this incident with the battery not charging. The new house batteries did not get above 11 v while on shore power in spite of the battery charger's best efforts. When we got underway the batteries dropped even lower. Then at one point I opened the throttle up to make a bridge before it closed and low and behold the batteries charged up in a couple of minutes and remained charged and doing their job for the next two days.

I am figuring there has to be a loose connection somewhere. The boat has been put to bed and I did not find anything while putting her up. Will try again in the winter,

Thanks

You do not say what Ranger Tug you have, but you may have a fuse in the charging line from the charger to the house batteries. If it blows, the charger works but the batteries do not charge. However running the engine will recharge the batteries if that fuse is blown.

 

[walldog]

I have a 2010 R-25 with the Nova Kool refrigerator. The refrigerator drew my old stock batteries down to 9v after two days at anchor and they were unable to hold a charge after that. I figured they were old with a ship date of Aug 09 so I replaced the original dual purpose batteries with Deka DC27s . Now the new batteries still are unable to keep the refrigerator going even when I have the battery charger on continuous shore power and I have everything else on the DC panel shut off. At this point the refrigerator which is set on "4" draws the batteries down to 11v which seems to be too low to keep the refrigerator running so I am losing this race. The refrigerator never really gets cold and the batteries never really hold a charge. The battery charger is the 1220i.

Thoughts, ideas, suggestions?

I note that you have the 1220i charger. I assume that you have checked the 30 amp fuse that is inline with the charger to battery line. If this fuse is blown, no charging current will go to the house batteries when on shore power, but the engine charging system will still charge the house batteries.