Go Back   iRV2 Forums > CAMPING, TRAVEL and TRIP PLANNING > Boondocking
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-21-2014, 08:39 PM   #1
Member
 
Join Date: Oct 2013
Location: Orange Park FL
Posts: 49
Inverter to run fridge

Question:

I have a mini fridge that according to the literature that came with it has running amps of 1.0 to 1.4 and a base voltage of 115V(127V max). It also states that it uses 60-80 watts (last 1/3 of cycle), I assume this means last 1/3 of the compressor cycle.

I have 2 84 amp hour house batteries. Interstate SRM-24, not the best but that is what came with the MH.

I want to buy an inverter to run only the fridge off of the 2 batteries.

Doing the math of figuring wattage I get 115 (1.0 x 115) to 177.8 (1.4 x 127).

No info on start up amps/watts in the fridge literature. So guesswork of doubling or tripling the amps/watts for start up would suggest a 500 watt inverter would work.

Based on this the fridge would only run for maybe 5-6 hours, is this right?

And all of this does not take into account the lights (all LED) and fans also depleting the batteries.

I know bigger amp hour batteries would extend the time as would solar panels.

Trying my best to use the existing batteries.
__________________

__________________
US Navy 1983-2003, C-130 F/E. 31' 1998 Southwind Storm P32 chassis, 7.4l (454), Toad 1998 VW Cabrio
gary276 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 10-21-2014, 09:27 PM   #2
Senior Member
 
mgscott4's Avatar
 
Workhorse Chassis Owner
Join Date: May 2009
Location: Kansas City, MO./Pollock, LA.
Posts: 1,549
I would get a 300 watt inverter, don't pay more than $30 for one. Amazon has a good selection. Most can handle 600 watt surge for compressor start-up.

The important thing is mount the inverter as close to the batteries as possible but not in the same compartment. You can probably get away with 10 AWG wire but I would go bigger to ensure little to no voltage drop. Don't forget to fuse it, in case of a catastrophic failure.

Try your existing batteries first, I will bet they work fine, because the fridge will only run for a few minutes each hour, once at operating temperature.

If you find out you need more batteries, then upgrade with 2 (6volt) golf cart batteries. GC2 batteries are true deep cycle batteries that have approximately 220 amp hours.
__________________

__________________
06 Hurricane 34FT WH W20 Chassis 8.1L 132K, Steersafe, Koni Shocks, DIY Trac Bar, Tri-Metric 2025RV Battery Monitor, 4-6V Batteries, Scan Gauge 2, Crossfires, 735W Solar Morningstar MPPT-60, WG T4 In-Motion Sat, XM Radio, 07 Chevy Malibu Maxx Toad, Falcon 2, Brake Buddy, Escapee
mgscott4 is offline   Reply With Quote
Old 10-21-2014, 09:30 PM   #3
Senior Member
 
mgscott4's Avatar
 
Workhorse Chassis Owner
Join Date: May 2009
Location: Kansas City, MO./Pollock, LA.
Posts: 1,549
You can buy this to see exactly what the refrigerator power consumption is.

P3 P4400 Kill A Watt Electricity Usage Monitor - Low Temperature Alarms - Amazon.com
__________________
06 Hurricane 34FT WH W20 Chassis 8.1L 132K, Steersafe, Koni Shocks, DIY Trac Bar, Tri-Metric 2025RV Battery Monitor, 4-6V Batteries, Scan Gauge 2, Crossfires, 735W Solar Morningstar MPPT-60, WG T4 In-Motion Sat, XM Radio, 07 Chevy Malibu Maxx Toad, Falcon 2, Brake Buddy, Escapee
mgscott4 is offline   Reply With Quote
Old 10-21-2014, 09:43 PM   #4
Member
 
Join Date: Oct 2013
Location: Orange Park FL
Posts: 49
Thanks

Thank you for the reply, you can get a headache trying to figure this out.
__________________
US Navy 1983-2003, C-130 F/E. 31' 1998 Southwind Storm P32 chassis, 7.4l (454), Toad 1998 VW Cabrio
gary276 is offline   Reply With Quote
Old 10-21-2014, 09:44 PM   #5
KIX
Senior Member
 
KIX's Avatar


 
Join Date: Dec 2006
Location: St. Augustine, FL
Posts: 3,579
I would suggest that you recharge your batteries when you have depleted the capacity by no more than 50%. Depleting them more can significantly shorten their usable life.
__________________
KIX
'02 Ultimate Advantage 40J Spartan MM - Cummins ISC
2013 Jeep Rubicon JK Unlimited
KIX is offline   Reply With Quote
Old 10-21-2014, 10:31 PM   #6
Senior Member
 
mgscott4's Avatar
 
Workhorse Chassis Owner
Join Date: May 2009
Location: Kansas City, MO./Pollock, LA.
Posts: 1,549
Quote:
Originally Posted by KIX View Post
I would suggest that you recharge your batteries when you have depleted the capacity by no more than 50%. Depleting them more can significantly shorten their usable life.

Yes, Kix is correct, but you need a good battery monitor to tell you where 50% is.

You can buy a hydrometer and measure specific gravity in each cell, the hydrometer will have a chart to reference specific gravity @ 50%.

Or use 12.0 volts as your low battery limit. This is close to 50%.
__________________
06 Hurricane 34FT WH W20 Chassis 8.1L 132K, Steersafe, Koni Shocks, DIY Trac Bar, Tri-Metric 2025RV Battery Monitor, 4-6V Batteries, Scan Gauge 2, Crossfires, 735W Solar Morningstar MPPT-60, WG T4 In-Motion Sat, XM Radio, 07 Chevy Malibu Maxx Toad, Falcon 2, Brake Buddy, Escapee
mgscott4 is offline   Reply With Quote
Old 10-23-2014, 12:08 PM   #7
Senior Member
 
Join Date: Jul 2012
Posts: 238
You should get a pure sine wave inverter as a modified one "may" damage your fridge. I would think 300 watts would be fine but it all depends on the startup surge. When you fill the fridge make sure the items are already cold and keep the door shut as much as possible, this will reduce the fridge run time. Also a empty fridge runs more than a fully stocked fridge with cold items already in it. Consider getting a icepack and put in fridge (freezer section if possible) to help and if you drink a lot of tasty beverages you may want to keep them in a cooler as you will constantly be opening the door.

As far as run time there are to many variables. Most importantly is the outside temperature and humidity. The inverter will also use some power and then you have the lights and other things you mentioned. Do you have a generator, if so you will want to top the batteries off morning and night.

I think you need to just go for it and see how it works out and report back here of course.
__________________
2014 Journey 34B
zman-az is offline   Reply With Quote
Old 10-23-2014, 01:10 PM   #8
Senior Member
 
vsheetz's Avatar


 
Fleetwood Owners Club
Ford Super Duty Owner
Join Date: Jun 2012
Location: SoCal
Posts: 11,807
If the manufacturer of the refrigerator states ok to use with a MSW inverter then good enough. If not specified I would go with a PSW inverter.
__________________
Vince and Susan
2011 Tiffin Phaeton 40QTH (Cummins ISC/Freightliner)
Flat towing a modified 2005 Jeep (Rubicon Wrangler)
Previously a 2002 Fleetwood Pace Arrow 37A and a 1995 Safari Trek 2830.
vsheetz is offline   Reply With Quote
Old 10-24-2014, 11:38 PM   #9
Senior Member
 
mgscott4's Avatar
 
Workhorse Chassis Owner
Join Date: May 2009
Location: Kansas City, MO./Pollock, LA.
Posts: 1,549
The only problem I have had with my Freedom 458 MSW 2000 watt inverter is one of the 2 electric blankets I bought, would not run on the MSW. The other one works fine.

My 3 TV's, Sat receiver, microwave, 2 laptops, hair dryer, hair clippers, 2 phone chargers, fan, and ice machine all operate with no problems. (Not at the same time)

I do not operate my Refrigerator or electric hot water heater on the inverter, not because of the MSW, but because they draw too much power, and I can operate them both on propane.
__________________

__________________
06 Hurricane 34FT WH W20 Chassis 8.1L 132K, Steersafe, Koni Shocks, DIY Trac Bar, Tri-Metric 2025RV Battery Monitor, 4-6V Batteries, Scan Gauge 2, Crossfires, 735W Solar Morningstar MPPT-60, WG T4 In-Motion Sat, XM Radio, 07 Chevy Malibu Maxx Toad, Falcon 2, Brake Buddy, Escapee
mgscott4 is offline   Reply With Quote
Reply

Tags
fridge, inverter



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Nifty way to run a Honda or Yamaha inverter Generator from your motorhome. Gerryl Class A Motorhome Discussions 21 05-08-2015 09:22 AM
Inverter | Transfer switch |Converter | Charger question jdwky RV Systems & Appliances 51 08-18-2014 12:02 AM
Researching adding an inverter AZCactus RV Systems & Appliances 2 07-08-2014 03:45 PM
Fridge Replacement rvjimzhr Class A Motorhome Discussions 52 03-20-2014 04:42 PM
Run A/C on Inverter while traveling? smiller RV Systems & Appliances 11 02-26-2014 02:13 PM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 05:07 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.