Batteries VS Residential Fridge

[99dart]

I know there have been many complaints about batteries not holding up very well. But, who has actually made an improvement/modification that helped battery life? And, what did you do to acheive better life?
My wife & I went out for a quick two nighter to try out dry camping. Things did not far well for the fridge. Our 2-6 volt batteries are two months old, they were fully charged (reading 13.6- 13.7 on the invertor readout) because the coach had been plugged in for the last 2 months. I checked the water 2 days before leaving, they were all nearly full. We drove 1 1/2 hrs, arriving at our weekend getaway location and setting up camp about 5pm. At 2:30am the invertor alarm woke me up. Obviously the batteries didn't last long at all.
Has anyone managed to dry camp overnight without a two battery system going dead? With just two of us we don't run much more than the two lights over the dinnette while playing cards.

[99dart]

BTW, my wife was pretty preturbed that we couldn't depend on battery power to run the fridge for one night!
I am figuring I will need to upgrade to four batteries at least to maintain the fridge. :/

[jpmihalk]

That was a lesson we learned with our old coach. It had 2 wet cell 12v batteries and the inverter would only make it 4-5 hours on battery power. We updated to AGM group 31 batteries and we could go 8-9 hours. There were some other parasitic drains on the batteries so we added 400 watts of solar to keep the batteries charged during daylight hours and limit generator usage. That helped overnight battery usage some, upping time on battery to around 10 hours.

In our new Thor Hurricane, we immediately had the dealer install two additional batteries and added 400 watts of solar panels. We have been dry camping frequently without issue but we wanted even more time so we just updated our 4 batteries to group 31 AGM Interstates. We are still waiting to see how they perform.

[TurnerFam]

not sure I follow your original post situation:

-were you drycamping at your arrival spot?

-if so, did you use your generator?
-if so, did you allow the generator to run an hour or so before bedtime?
-do you have an AGS(AutomaticGeneratorStarter) to provide charging when needed?

for the 'fridge':
-is it hot outside?
-do you leave it on a 'high' setting overnight when not in use?
-were the items you packed into the fridge for your trip already cold?
-do you leave your ice maker on during the overnight?


I've found that a fridge cycles on and off during it's power cycle, not always on as some of us might think. It powers the compressor on only when it needs to reduce the temperature. Sometimes, though, we only mention the fridge and the batteries in our complaint, and forget that there are other things we are using and that are being powered during the night, such as lights of course, but also device chargers for our phones and tablets, 12v items that run all the time like o2 sensor and smoke detectors, and the water pump, when in use.

some methods to reduce the need for fridge, or battery power, overnight:
-turn the temp level up to it's 'highest' setting, or some even turn the fridge OFF
-if using a generator, allow the generator to run for an hour or two before bedtime, keeping the fridge temp at it's lowest setting. turn the fridge temp back up right before turning the generator off. This will allow the generator to get the fridge as cold as possible right before the overnight hours, with much less need to run during the night.

Many of us 'want' the inverter and batteries, no matter how many we have, to keep us and all our appliances 'cumfy thru the night, but most coaches are probably not going to be able to always do everything we think they should. Coach builders install two 6v deep cycle batteries as a way to help provide the potential for overnight running of the fridge, but there are many times too many variables to hold them to a 'guarantee' that it will do it.

also, you mentioned your 'alarm' from your inverter. I suppose you are referring to your LBCO(LowBatteryCutoff)? if so, this provides a method to cut off your inverter(fridge power) when your batteries reach a certain Voltage level. You can set this level yourself, just like you set your AGS Voltage setting to tell the Generator when to start up. The LBCO might be too high, giving you 'less' time on the inverter. If you want, try a lower setting, and see if that gets you thru the night. The drawback is that you could have it set so low that the generator won't start, but a little trial and error will help you identify the best setting. We use 11.8 on our AGS, and 11.1 on our LBCO.

oh, by the way, we have FOUR 6v batteries, and we rarely get thru a night without the AGS running the generator during that time. The less the better, of course, but the most aggravating is when a campground with no hookups has a very strict generator usage rule. One we had in the Yukon recently, at Liard Hot Springs, was only between the hours of 8am and 9am, and 6pm and 8pm. What?? There were kids running around screaming at 10pm, and folks laughing around fires, but we couldn't run our generator?? 'Quiet Time' was posted as 11pm to 7am.

[blw2]

You know what we really need is for someone to invent a fridge that works with propane.... I mean we are hauling around this big tank of the stuff that barely gets used and that could be great! I'll bet you could run a month with it!

Seriously, I only have experience with absorption fridges in RV's, but it seems to me that big variables that would affect this issue are
prechilling the fridge before going on battery
and making sure the fridge is FULL of stuff for the greatest thermal mass possible. Fill the fridge and freezer with as much water bottles as possible to fill any air spaces.

The other thing that I guess would just be luck of the draw, is that I'm assuming these are frost free fridges. I have no idea if newer frost free fridges are the same, but it used to be that they had a simple mechanical timer that would periodically kick on a heating element. As far as I ever knew there was no way to know when that would kick on and no practical way to override it except unplug the element. Maybe these fridges are different, but personally, if I were in your shoes I would look into how these newer fridges operate and possibly disable the frost free system.

[99dart]

Originally Posted by TurnerFam

not sure I follow your original post situation:

-were you drycamping at your arrival spot?

-if so, did you use your generator?
-if so, did you allow the generator to run an hour or so before bedtime?
-do you have an AGS(AutomaticGeneratorStarter) to provide charging when needed?

for the 'fridge':
-is it hot outside?
-do you leave it on a 'high' setting overnight when not in use?
-were the items you packed into the fridge for your trip already cold?
-do you leave your ice maker on during the overnight?


also, you mentioned your 'alarm' from your inverter. I suppose you are referring to your LBCO(LowBatteryCutoff)? if so, this provides a method to cut off your inverter(fridge power) when your batteries reach a certain Voltage level. You can set this level yourself, just like you set your AGS Voltage setting to tell the Generator when to start up. The LBCO might be too high, giving you 'less' time on the inverter. If you want, try a lower setting, and see if that gets you thru the night. The drawback is that you could have it set so low that the generator won't start, but a little trial and error will help you identify the best setting. We use 11.8 on our AGS, and 11.1 on our LBCO.
oh, by the way, we have FOUR 6v batteries, and we rarely get thru a night without the AGS running the generator during that time.

Thanks for your reply. We are new to all the sophisticated gadgetry in this MH. In our old 1998 we started the genni when the furnace would no longer turn on or the carbon monoxide sensor started yelping! LOL
Yes, we were dry camping, nothing but us and nature. BTW, our coach came with two 12v batteries,but were shot. I "supposedly" upgraded to two 6v wet cell batteries. I did run the genni to run the AC for roughly an hr. The thermometer in the fridge was showing 34-35 degrees. We decided we would turn the fridge off for the night, so around 7:30pm we turned it off(oddly enough, I did think to push the arm up on the ice maker) to preserve power. Around 10pm we went to bed, so I checked the therm in fridge, 41*. I turned it back on to a low setting to hopefully maintain thru the night. Later is when the LBCO woke me. (this is where I need to figure out the adjustment) I then started the genni (2:30am) and sat up for an hr watching the "charge" condition. It didn't change from 12.0 the entire time! I shut down the genni, then the LBCO started again. In frustration I turned off the inverter and fell asleep on the couch. When I woke up I started the V10 (turned on the in dash heater, it was 59*) then, turned on the inverter. It was showing it was then charging, up over 12v don't remember exactly. I alternated running the genni or the V10 probably 3- 3 1/2 hrs during that day. That night was a repeat of the previous night.

So, to summarize.
I need to do some trial & error with the LBCO & AGS. Thanks for including your settings as a starting point.
Have the fridge on the coldest setting possible going into the night time. Turn off the Ice maker and any other un-necassary power draw. Which I always do. I think I will move the ice bin from the freezer to the fridge from now on.
AND, invest in having two more batteries installed. If needed, I have a friend that can weld up a battery tray.

Thanks again to all that have replied with ideas to "Help me make it thru the night"! Who sang that?! LOL

[99dart]

Originally Posted by blw2

You know what we really need is for someone to invent a fridge that works with propane.... I mean we are hauling around this big tank of the stuff that barely gets used and that could be great! I'll bet you could run a month with it!
if I were in your shoes I would look into how these newer fridges operate and possibly disable the frost free system.

My wife and I knew we were taking a gamble buying this coach having a resi-fridge in it. But, we really wanted the floor plan w/cabover entertainment center. We always did great with our propane powered fridge in the old coach. We always turned it on 3- 5 days before a trip and loaded it with already cold items.
I like your thought about finding out if the fridge has a defrost cycle. I will investigate that!
Hmmm... maybe I should have a propane fridge installed... never mind!

[99dart]

Originally Posted by jpmihalk

That was a lesson we learned with our old coach. It had 2 wet cell 12v batteries and the inverter would only make it 4-5 hours on battery power. We updated to AGM group 31 batteries and we could go 8-9 hours. There were some other parasitic drains on the batteries so we added 400 watts of solar to keep the batteries charged during daylight hours and limit generator usage. That helped overnight battery usage some, upping time on battery to around 10 hours.

In our new Thor Hurricane, we immediately had the dealer install two additional batteries and added 400 watts of solar panels. We have been dry camping frequently without issue but we wanted even more time so we just updated our 4 batteries to group 31 AGM Interstates. We are still waiting to see how they perform.

I REALLY like AGM batteries! I had a single Odyssey 1700 in our old coach. I liked how it would re-charge really quickly when it finally did need charged. I use a little 925 Odyssey in my race/show truck. It does an outstanding job! It spins over the 10.8 to 1 compression motor faster than anything else!
I found this Apex battery site. It wonder how good their AGM 6v would hold up?
https://www.apexbattery.com/golf-car...0-battery.html

[doubravsky]

We also added 2 extra batteries and 400 watts of solar, which keeps things charged during the day and limits generator usage.

We found that if we just turn off the inverter when we go to bed, everything stays nice and cold til morning, even in the summer heat. And the battery drain is minimized.

[99dart]

Originally Posted by doubravsky

We also added 2 extra batteries and 400 watts of solar, which keeps things charged during the day and limits generator usage.

We found that if we just turn off the inverter when we go to bed, everything stays nice and cold til morning, even in the summer heat. And the battery drain is minimized.

Kewl! Thanks for your posting your "fix" and results! Did you install the 400w solar system? How technical was it if you did? Thanks!

[doubravsky]

I didn't do the install... found a referral for a guy that works at a camping world by day and does side jobs. Cost me $1700 for the panels/controller/extra batteries/install..... was a great investment.

[99dart]

So, I was just outside (92°) under the MH looking at our battery tray. It looks like it WILL hold 4 batteries! Am I hallucinating? Did Thor actually do something that would make THINGS EASIER for us?? There are however a bunch of wires that will need to be tucked/pulled up out of the way. One being a large jacketed flexible conduit. It will take some "messin' about", but I should be able to do it myself. YAY!

[99dart]

Originally Posted by doubravsky

I didn't do the install... found a referral for a guy that works at a camping world by day and does side jobs. Cost me $1700 for the panels/controller/extra batteries/install..... was a great investment.

Oh, I forgot to ask. Are your batteries 6v or 12v, wet cell or AGM?

[jpmihalk]

We did our own install of the solar power system. It was fairly easy with the right info and tools. The challenging part was figuring out where the cable runs to the controller and to the batteries would be routed.

[scrubjaysnest]

Our friends have a resi frig, and 4 6 volt batteries for 432 aH of capacity. With no solar they have to run the ginney 5 hours per day. From our experience 500 watts of solar is good with 210 aH of battery, we also have a LP refrig. We last had shore power the first week in May and have been dry camping since then. We may have shore power for the first time since then with a stop in NM after Labor Day.

For our friends set up they would almost need 1000 watts of solar. 500 is good enough to reduce ginney run time.

[wredman]

question for you solar guys

How much generator time will you reduce with average conditions of 300 watts of solar every day. Assuming your daily usage will exceed you solar potential.

[Bob Denman]

As a "newbie": I'm starting to learn about all of the stuff that I'll need to learn!
(And it's a little bit scary!)
I think that our Oullaw has two batteries tucked up under it's belly. Would it be worthwhile to ask the dealership about an upgrade to AGM batteries before taking it off of the lot?

[TurnerFam]

Originally Posted by 99dart

Around 10pm we went to bed, so I checked the therm in fridge, 41*. I turned it back on to a low setting to hopefully maintain thru the night. Later is when the LBCO woke me. (this is where I need to figure out the adjustment) I then started the genni (2:30am) and sat up for an hr watching the "charge" condition. It didn't change from 12.0 the entire time! I shut down the genni, then the LBCO started again. In frustration I turned off the inverter ...

my question: are you sure the CHARGER was on?

The inverter only inverts, meaning changing battery 12v power to 120v power for the fridge and other 120v outlets, when you have no generator or shore power(dry camping).
The converter converts 120v power, when you are on shore power or generator power, down to 12v to power lights, and other 12v items.
The CHARGER charges the batteries when you have it on and the Generator is putting out power(make sure the generator breaker is not tripped), or on Shore Power.

You also have a SHORE MAX button/setting on the Magnum info panel. It allows you to set the 'Max' amperage that the Charger can use while you have the generator running, or are on Shore Power. If you have this set too low, such as 5 or 10amps, while the generator is running, you won't get much of a recharge for the batteries, setting it up to 40 or 50amps will give you the most charge to the batteries while the generator is running, still allowing for other 120v and 12v items to be used, such as TVs, lights, etc.

[Chance]

Originally Posted by wredman

question for you solar guys

How much generator time will you reduce with average conditions of 300 watts of solar every day. Assuming your daily usage will exceed you solar potential.

Not a solar guy but will give you my educated guess.

As with most things, it depends on many factors. But you can make reasonable assumptions and get close to the right answer, which can't be known exactly until you try it.

First, how efficient is solar system -- they are not all equal. If you're talking about 300 watts of nominal panel capacity, and installed flat on roof, I'd guess you might get "about" 1,000 ~ 1200 watt-hours of energy into batteries.

On a 12 Volt system that's roughly 100 Amp-hours. It's really not that much.

So how long would it take a generator to offset 100 A-h? Mostly it would depend on converter capacity, how many batteries are there to accept the charge, and what type of batteries they are. With lithium batteries that accept charge faster, as an example, combined with high-capacity converter, a generator may accomplish the same energy in an hour or so.

With 4 flooded batteries it would take less time than with 2 similar batteries to store the same 100 Amp-hours of energy, etc.; provided converter can deliver current capacity.

Some of the entry level motorhomes have limited converter capacity, and small battery bank capacity, so it could easily take 2 hours, maybe a little more.

In my opinion it could vary a lot, but I can see roughly in 1 to 2 hour range being fairly common.

[Bob Denman]

Originally Posted by TurnerFam

You also have a SHORE MAX button/setting on the Magnum info panel. It allows you to set the 'Max' amperage that the Charger can use while you have the generator running, or are on Shore Power. If you have this set too low, such as 5 or 10amps, while the generator is running, you won't get much of a recharge for the batteries, setting it up to 40 or 50amps will give you the most charge to the batteries while the generator is running, still allowing for other 120v and 12v items to be used, such as TVs, lights, etc.

Question: Is this a feature that is included on ALL rigs?