Dud battery, or just not enough sunlight?

[Karate Chopped]

Also just tonged the fridge and it's drawing close to 4A, which is no surprise that it's nearly double what the sales brochure says.
Panels are putting out 7A in the morning sun, and I'll keep measuring throughout the day to see what it can do in midday sun.

On top of that, I'll do a battery hydro test.

Lots of lessons learnt here.

 

[peesalot]

Thats not suprising, that fridge is gonna work the batts a fair bit harder than a more efficient fridge.

 

[sdnative]

Also just tonged the fridge and it's drawing close to 4A, which is no surprise that it's nearly double what the sales brochure says.
Panels are putting out 7A in the morning sun, and I'll keep measuring throughout the day to see what it can do in midday sun.

On top of that, I'll do a battery hydro test.

Lots of lessons learnt here.

That seems good actually. The ARB 45L fridge/freezer (single zone) draws over 5A. Unless you mean Ah.

 

[Karate Chopped]

That seems good actually. The ARB 45L fridge/freezer (single zone) draws over 5A. Unless you mean Ah.

Nope, amps.... as we know Ah is a total volume of charge.

24hrs later and the battery is still sitting at high twelves, but I may have overfilled my battery so hopefully some of the water will boil off and it will perform better. But its definitely holding charge better and less drop under load.

Crisis over.

 

[e9999]

well, dang, I just learn something new every day. Never knew that it would get down to -15C in Oz. I just thought that place was hot .. Or did I miss something with these graphs...?

 

[Karate Chopped]

well, dang, I just learn something new every day. Never knew that it would get down to -15C in Oz. I just thought that place was hot .. Or did I miss something with these graphs...?

Yeah, that's the chamber temp in the freezer, so technically a very specific spot in Australia is -15degC!

But where I live it often gets down to 0degC and some snow every couple of years. Also gets to high 40s in summer, so its still hot.

 

[e9999]

LOL. Note to self: don't try to be funny late at night...

 

[Karate Chopped]

Although it does get cold near the capital of Vienna.

 

[peesalot]

How is the arb 45 using 5 amps ? real world data shows 1.2 amps an hour in normal temps. It might surge to 5 amps momentarily on start up.
Are the ARB's using seacop/danfoss motors now ?

 

[george_tlc]

^ We just need people to use the units correctly AND consistently.

The ARB can draw 5A and in an hour of typical use (where it runs 5 minute on and 15 minutes off) 5A x 15/60 = 1.25AH

cheers,
george.

 

[peesalot]

I get it but some would read that as it has a 5 amp continuos draw when running.

 

[peesalot]

Now, the lower priced units with the seacop/danfoss, theres a ton of em, I could believe a 3 or 4 amp draw - thats why IMO the more expensive fridges really pay off in the durability and consumption, I tried an aspenora 42qt, 350 bucks, used it a few years, it did the job but had a finicky low voltage cut out and the lid was s***, cycled more often and had a larger draw when running which just taxed the batts a bit more, my system kept up but it much less cycling and higher overall system voltage maintained with the engel.

 

[sdnative]

I get it but some would read that as it has a 5 amp continuos draw when running.

It does.

 

[peesalot]

sdnative is correct, the running draw is 5 amps, why is this important, because NONE of the fridge manufacturers that I looked at list this data in the specs. Why does that matter ? Because the use data listed refers to a specific test parameter, in real world you open the fridge more or less, temps go up and/or down, simply put you have to know that running amp use to acurately determine power consumption based on how much run time your fridge ran in an hour or over 24 hrs.
Can you run a fridge 3 or 4 days without starting vehicle or having solar, IMO, maybe depending on your other draws & batt condition. I like to have it so I can let it sit indefinitely (given sun) and use it at will regardless of outside temp without worry, so far so good, with 2 batts & 100w of solar.

 

[sdnative]

Every fridge is going to cycle on and off. So in my case (ARB fridge) the compressor draws about 5A when running, and of course 0A when not running. In my climate and with the insulation jacket installed, the compressor runs about 20% of the time. So for an average hour the fridge consumes roughly 5A * 1h * 0.2 = 1.0Ah, which aligns fairly well with published specs. As long as the power distribution is designed for the current draw, the 5A is not a problem. It really is the Ah that matters for battery life and sizing. A group 27 lead acid battery can supply around 40 *usable* Ah, so it can run my fridge for 1.5-2 days before voltage drops to ~10.5V but YMMV.

I don't care for the ARB specs that say, for example, 0.85 A/h. Amps is an instantaneous value (like power), not an accumulated value so that doesn't make sense to me. Better to specify compressor amperage draw, duty cycle (compressor time on vs off), and corresponding Ah consumption. Even better would be to specify compressor power consumption and corresponding energy (Wh) usage, that way remove voltage (variable) from the equation. Compressor power consumption should be constant regardless of battery voltage.