ARB Fridge and Battery Consumption

[NW European]

I see a lot of threads and questions about this, so figured I would share my real world data...

I have a brand new ARB Fridge, and a brand new Sears DieHard Platinum 31M Marine deep cycle battery. Bought both based on reviews, comments, etc. on here and on MUD (I have a Land Cruiser). Started the dual battery install the other night, but had not yet finished all the wiring. The weather cleared here and decided to do a one night camping excursion. So I did a beta test of the set-up....

Loaded the fridge to about 75% of capacity with a variety of food and drinks. Set the target temp to 31 degrees. Used 120V at home to get it down to temp -- worked great, was pretty quick to get cold, did not measure this part.

Put the fridge and the battery in the Land Cruiser at 1pm on Wednesday - nothing but the fridge connected. Measured voltage at the posts - 13.33
Monitored it at the posts over the evening, and the in morning, and all the way to back home...at conveniently - 1pm! Voltage then - 12.66

Ambient temperature was near 70 during the day, maybe 40 overnight up in the hills.

The battery was NOT connected to the truck wiring, just the ARB fridge -- so it was only being drawn down, nothing adding to it. Just thought I'd share the real world data for fun.

[Countryboy69]

Thanks for the info. It should help alot of people on here. It did good to last. I bet you might get another day and half out of it. Good job on having your batt charged up that much as well. Most people think 12.6 is a full batt. You got a free day out of that battery by having it actually fully charged

[kevint]

Was the fridge still connected when uou measured the 12.66?

[HillbillyfromAL]

So was it just one day? Also was the fridge actually, running green light on, when you tested it? If the compressor was running it'd be pulling the Amos and you wouldn't actually get a very good reading of the battery. I'd say charge it up again and just see how many days you get before the light starts blinking red.

[NW European]

Fridge was disconnected for both readings. At install and uninstall for the 24 hour camping trip. I was just curious and thought I would post my results to share.

[kevint]

Thanks for the input.

I've been tracking fridge power consumption here.

http://www.expeditionportal.com/foru...ad.php?t=78736

If you're able to make an estimate of amp-hours in a test, it would be nice to have you contribute some data.

Thanks.

[Colin Hughes]

Last summer during our main camping trip, the outside temperature ran around 32-35 C most days. I parked the truck Monday, with a couple of short drives between then and Thursday evening, when the second battery started to get to the point the LO warning came on the ARB fridge. A lot of that time, there was not much shade so the fridge was in a hot truck (even with the windows down). I just purchased a 100w solar panel setup to hook up to the aux battery when we're camped so hopefully I won't see the Lo warning again when we're camped for an extended period.

[4x4junkie]

Thanks for the info. It should help alot of people on here. It did good to last. I bet you might get another day and half out of it. Good job on having your batt charged up that much as well. Most people think 12.6 is a full batt. You got a free day out of that battery by having it actually fully charged

12.65V is infact a full batt (12.78V for an AGM type).
http://jgdarden.com/batteryfaq/carfaq4.htm#ocv_soc

At 13.3V it must've still had some residual voltage left on it from immediately taking it off the charger.

[Countryboy69]

Odyssey, the maker of that battery states an open current voltage of 12.84 or higher at 25 degrees after being unhooked for at least 6 hours for a fully charged batt.

[Countryboy69]

Here is a good site on charging batteries. http://handybobsolar.wordpress.com/t...ging-puzzle-2/