fridge draw

[colin k]

I recently installed a fridge in my 13 foot boler. (2 way 120 ac and 12v.). Its a small norcold . Just curious as to how much draw (amps) i can expect. It will be powered by a deep cycle 12v battery probably an optima yellow top. How long can i expect the battery to power the fridge before the battery needs recharging?
Thanks.

BTW. The boler is almost finished. Will post pics when the reno is complete.

[Byron Kinnaman]

It's really hard to say how much it draws. If you have the manual it should tell you. If you don't have the manual, get the model number and go to Norcold's web site and down load it. Once we know how much current it draws in DC mode an estimate on battery life can be made.

[colin k]

Hi. I got the manual with the fridge and there are no specs on power consumption. It has everything else like air venting tolerances,mounting tolerences but nothing on draw. Weird.

[Dan Meyer]

If your 'fridge draws 60 watts (it's proabably double that) while on 12 volts, that works out to 5 amps. That will translate into 16 hours from a typical 80 amp hour group 24 battery. This is also drawing the battery completely dead, which isn't the greatest thing even for a deep cycle battery.

For more information about batteries and how to use and maintain them, go to http://www.batteryfaq.org

-- Dan Meyer

[Steve C.]

I recently installed a fridge in my 13 foot boler. (2 way 120 ac and 12v.). Its a small norcold . Just curious as to how much draw (amps) i can expect. It will be powered by a deep cycle 12v battery probably an optima yellow top. How long can i expect the battery to power the fridge before the battery needs recharging?
Thanks.

BTW. The boler is almost finished. Will post pics when the reno is complete.

You may want to reconsider the use of the optima yellow top if you want the frige to run for a good length of time. These batteries are rugged and reliable but have very low reserve capacities (C/20 Rate 55AH or less) compared to other conventional deep cycle batteries that are rated at 80-105AH for a physically similar sized battery.

Steve.

[colin k]

Hmmm. What battery would you recommend? I need as much reserve as i can get. Optimas are not very wallet friendly either.

[Byron Kinnaman]

I just checked the Norcold web site. The 2 ways draw between 2.5 and 3 amp at 12 Volts. Group 24 batteries are 75 to 80 amp hours. If you don't run anyother 12 Volt items you're out of battery in approximately 24 hours ± a couple hours.

If you're going to be away from 120 Volts for a week-end freeze some ice and use it like a cooler. You could run it while traveling but turn it off when camped.

If you're going to be away from 120 volts for long periods of time, sell it and get a 3 way.

[Steve C.]

Hmmm. What battery would you recommend? I need as much reserve as i can get. Optimas are not very wallet friendly either.

I guess it depends on how much room you have available for batteries, and if you really require a sealed spill proof battery.

If you have the room, a pair of 6V golf cart batteries in series will give an economical 225AH of capacity. If you are like me, with room for only one, check out the 12V Trojan SCS225 or 30XHS with 130AH. I think when mine finally dies, I will look at the newly released Trojan J150, with 150 AH capacity. These quality batteries are not cheap, but do offer high capacity in a relatively compact package. However, vented lead acid batteries probably should not be placed inside a trailer unless you can provide a sealed and externally vented battery box. I have mine mounted out on the trailer tongue.

If you require a high capacity sealed deep cycle battery, an expensive AGM style battery is a good choice. The best, and priced accordingly.

Steve.

[Steve L.]

Practical Sailor just did a test of deep cycle batteries in the group 27 to 31 range. They do a pretty fair comparison and are not sponsored. The Optima group 27 size was 25% below typical lead acid batteries in amp hour capacity for the same group size. Unless you plan on doing aerobatics with your trailer, they're not an optimum (Wah! I slay me!) choice.

AGM's are good, but sometimes want a charger with different charge programs for different battery chemistries. Seems a shame to me to spring for the AGM (which is a pretty slick bit of technology) but slowly degrade it with a commom battery charger.

Cramming the biggest lead acid battery in there that fits would be my approach. Still and all, I'm glad to have the propane option on my reefer. I know they're more expensive, but I expect they pay for themselves in a few years what with battery replacement, and the difficult to price convenience factor.

[colin k]

Well. I spent a full year looking for a fridge and i was not about to prend $7 -$800 on a 3 way that is too large for my boler.Everything i found new was too large. This fridge i finally found was out of a vanamera campervan. I bought everything out of the van ,the 30 gal automotive propane tank,stove ,fridge,sink,watertank. All brand new never used. Since i bought my boler gutted of appliances it was a good score. $270. We dont camp for longer than a few days usually on long weekends so i figured a 2 way will have to do.
Thanks for the battery advice. If we end up keeping this particular boler i will get a solar panel and charge the battery with that.
The battery BTW has to go inside the boler under the front bunk. The propane tank is on the tongue so battery goes inside.

[Steve L.]

Good luck and let us know how the solar works out.

I like the idea of solar, but I looked at the average solar load tables for Michigan, and combined with the fact that I like to camp in the woods and the price of 70-100 watt panels and couldn't justify it in the end.

3 amps an hour times 24 hours is 72 amp hours a day for the reefer. If I assume I'm only running the compressor 20% of the time, that would be about 14.5 amp hours a day to replace. A 50 watt panel, perfectly located in full sunshine and always pointing directly sunward, would provide about 3.7 amps of recharge power (at about 13.5 volts), so you can replace your battery drain in about 4 hours of sunny weather. Quicker if you get a bigger panel. I suppose smaller panels, while they wouldn't replace what you use will at least extend the time some.

A 50 watt panel will go for around about $300, not counting the charge controller. Arizona RV Solar has packages. I don't know how competitive they are.

[Brian B-P]

You may want to reconsider the use of the optima yellow top if you want the frige to run for a good length of time. These batteries are rugged and reliable but have very low reserve capacities (C/20 Rate 55AH or less) compared to other conventional deep cycle batteries that are rated at 80-105AH for a physically similar sized battery.

Steve.

There are a significant number of Optima battery models, and a C/20 rate capacity of 55AH suggests a group 34 size, which is relatively small unit. At C/20 rate, the group 31 (D31) marine (blue top) or commercial (yellow top) dual purpose units have a 75 AH capacity, for instance. Unfortunately, where I have seen Optima batteries in stores, only the smaller sizes (such as the yellow top D34) are stocked.

Optima batteries - and AGM batteries in general - are expensive, which is probably one reason for not stocking the larger sizes, and the main reason I don't have one.

I'm not saying Optimas are the ultimate RV battery, and I don't have any experience with them; I'm just saying that the capacity of any battery should be considered in the context of its size and (more importantly in a trailer) weight.

[Steve L.]

I did a quick search as well and pretty much confirm what Brian found. The largest amp hour capacity Optima battery that I can find quickly that is about the size of the traditional group 27 is the blue D31M that he refers to. 75 AH as reported. Froogle show about $190. None of the yellow tops I can find are much over the 55 AH mentioned so I can't see yellow tops as much of a RV deep cycle candidate in a 12v load environment.

Two springs ago I bought an Exide Stowaway group 27. Rated at 105 AH for about $95. I can't find a spec weight for it, but it's a heavy puppy. Heavier than the Exide group 27 that came with the new trailer.

If the situation requires the battery be inside the trailer, and it can't be boxed in and vented outside, one's options are limited I suppose. 12v drains are going to be a bear to deal with.

[Benny K]

Why can`t the propane bottle be moved over a few inches to allow room for a battery next to it? I have a 74 '13 and that`s what I did....check my webshots site. ...Benny

[Brian B-P]

...None of the yellow tops I can find are much over the 55 AH mentioned so I can't see yellow tops as much of a RV deep cycle candidate in a 12v load environment...

The bigger Optima yellow-tops are found in their Commerical selection, not under Automotive; from what I have read, these guys make a good product, but not a really easy-to-use web site. A while ago, someone even found a 3-cell (6V) product on a distributor's website which Optima doesn't list on their own site. I have no idea of cost or availability of any version except what I see at Costco.

12V batteries can be combined in parallel just as 6V batteries can be combined in series - either way works, so either approach can be used to build a high-capacity battery set from units you can find, and lift. Of course, two big Optimas would take a pile of cash, and I agree it's probably not the ideal route for most of us.

[colin k]

Thanks for the battery tips. I have decided on 2 gel wheelchair batteries in parallel. That should do me. I am going to build an enclosure at the back of the boler to distribute the weight between the front tank and the 2 batteries. I figure a 30 lb propane tank and batteries mounted on the tongue was WAY too much weight.
Benny K. I cant really mount a battery on the front tongue because the tank i mounted is a horizontally mounted tank the same as mounted under a van or truck. You know the kind that are permanently mounted under a vehicle.

[Brian B-P]

Colin, I read back through this thread when you reminded us of the horizontal tank, and now I'm wondering: is that a 30 lb propane tank, or 30 gallons (your first description)? Even 30 lb would be enough, but I think 30 gallons at 80% full would be about 80 or 90 pounds of propane.
I can see how the battery can't go beside it; how long is this tank?

[colin k]

Hmmm. 30 lb or 30 gallon. hmmm. Good question. The tank is 29 inches long and 11 inches high . Looks like a tylenol capsule. Has a guage on it. A big filler nossle . An overflow thing, and the flow tap. Its out of a vanamera van which was mounted i assume under the van as it was undercoated in black undercoat. Its now white. Since a bbq tank is 20 lbs and this tank is a little bigger because its longer i assumed 30 lb tank. But i dunno .

[Brian B-P]

.... The tank is 29 inches long and 11 inches high . Looks like a tylenol capsule. Has a guage on it. A big filler nossle . An overflow thing, and the flow tap... Since a bbq tank is 20 lbs and this tank is a little bigger because its longer i assumed 30 lb tank...

If that 29 inches is all tank (not brackets or guards) then I would guess about 45 litres capacity, or about 45 lb of propane at 80% full. Maybe smaller if some of that length isn't tank. Sounds like a good size for endurance, and a good fit across the A-frame of the trailer. The gauge will be nice to have, if it is a real liquid level gauge.

The Manchester Tank specs show a 30-lb horizontal tank as 12.2" in diameter, and only 19.6" long (cylinder body) or 23.4" overall (with valves and guard on one end). Colin's is presumably an RV tank, but Manchester's online RV Products page doesn't give specs.

[colin k]

Yup. 29 inches and all tank. The brackets are under each end of the tank. So the tank fits perfectly across the widest part of the tongue. The guage is like a cars gas guage with a red needle encased in glass. I didnt want a tank this big but since i got it i might as well use it . If i sell the boler down the road the tank stays with it. Its just too bad the fridge wasnt a 3 way but i will have to make due until i figure out a good solar setup. I am thinking about having an array over the back window so when the boler isnt in use the array is down. In use and the array is up.

I figure with this tank and the only thing that is run by propane is the stove i should be good to go for about 10 years.