My DC frig/freezer should be here today!

[RJ Howell]

I decided to go with a DC frig/freezer since so many are now using and quality/efficiency has as well (pricing down a bit ).

I went a bit bigger (70qt) due to we are used to the size and know how long between provisioning we can go. Being this is a chest vs. our old upright hey many a day longer?? Big wonderment is power consumption, you know, real life. Rated as 60 watt (hopefully max) and not knowing the cycling rate (duty cycle?), I'm very curious what the real power consumption will be.

I realize there are major difference of area and temp, but given a average 70F, mostly sunny day in the Forest... and pre-chilled... any thoughts on consumption? Best number I've seen say it runs about 40% on 60% off. So that could be about <580 watts in a 24hr period. That sound right??

[John61CT]

Use Ah per 24hrs as your benchmark,

watts or amps are real-time instantaneous units, not accumulative over time.

The real key to major efficiency improvements is thicker insulation.

And of course keeping it in a cool shady spot, lots of ventilation of the condenser / electronics area helps too.

Thermostat setting makes a **huge** difference.

As an example, just keeping drinks cold & stopping spoilage for a long weekend, assuming everything pre-chilled before heading off

might use 15-20Ah/day.

But living full-time where you want a true food-safe setpoint, might go to 30-35Ah.

And using as a freezer 70Ah, really keeping ice cream rock hard 90Ah.

All in exactly the same conditions among the other relevant factors

like keeping the spaces full of thermal mass, how often opening the hatch, adding some contents that have not been pre-chilled, etc.

[Florida Native]

My generic 30L runs about 15% of the time sitting inside a climate controlled house when set to 36F.

-Mike

Sent from my SM-G950U using Tapatalk

[RJ Howell]

Use Ah per 24hrs as your benchmark,

watts or amps are real-time instantaneous units, not accumulative over time.

The real key to major efficiency improvements is thicker insulation.

And of course keeping it in a cool shady spot, lots of ventilation of the condenser / electronics area helps too.

Thermostat setting makes a **huge** difference.

As an example, just keeping drinks cold & stopping spoilage for a long weekend, assuming everything pre-chilled before heading off

might use 15-20Ah/day.

But living full-time where you want a true food-safe setpoint, might go to 30-35Ah.

And using as a freezer 70Ah, really keeping ice cream rock hard 90Ah.

All in exactly the same conditions among the other relevant factors

like keeping the spaces full of thermal mass, how often opening the hatch, adding some contents that have not been pre-chilled, etc.

Is this real life usage? Your food safe numbers seem low to me, but like them if 'real life' numbers. Looks like a 30/70 (on/off) duty cycle.

And of course, all this relevant to temperature, ambient and setting.

[RJ Howell]

My generic 30L runs about 15% of the time sitting inside a climate controlled house when set to 36F.

-Mike

Sent from my SM-G950U using Tapatalk

That sounds real good!. So safe to say 72°F in the house?

[Florida Native]

Yes, wife keeps the house at 74F but may be a little cooler where the fridge is. Mine is a Costway and runs about 3 - 3.5 minutes and then is off for about 20-21. Set at 36F. Only opened maybe a couple times a day. Beer/cider and backup NA drinks for the main fridge. Been running it non-stop since quarantine started.

-Mike

Sent from my SM-G950U using Tapatalk

[John61CT]

Looks like a 30/70 (on/off) duty cycle.

And of course, all this relevant to temperature, ambient and setting.

All the factors have an impact.

The duty cycle ratio is only "important" in the sense you know you have room for hotter ambients or colder temp setting or adding warm stuff etc.

But really the Ah per 24hrs is the apples to apples bottom line.

Timing really only is an issue like with a eutectic "holding plate" system. might run 3hours once a day, so you time that for when you have free / surplus energy

[bdosborn]

Here's the electrical usage of both of my DC compressor fridges:

http://tnttt.com/viewtopic.php?f=2&t=46331

My Tundra fridge is probably close to your 70 qt in size...

Bruce

[RJ Howell]

Here's the electrical usage of both of my DC compressor fridges:

http://tnttt.com/viewtopic.php?f=2&t=46331

My Tundra fridge is probably close to your 70 qt in size...

Bruce

That is some great information there! Thank you for doing that!

[bdosborn]

Love me some graphs!

Bruce

[RJ Howell]

Just started the DC run this at 8:30am. Approaching 5pm, 8.5hrs so far. Setting is at 36°F, ambient is 75°F and inside the house. It was cold already from running it on AC with the 1/2 case of water in it. I don't have my meter on it, so I'm going by Voltage and my SOC chart for Lipo. Start was 13.4 (99%), went quickly to 13.3 (90%) and has stayed there since. I was working near it for a couple hours and when it runs it's only for a few minutes and only a couple times an hour so far.

I'm pleased so far!

[bdosborn]

I haven't bought ice in10 years and I don't miss it one bit.
Bruce

[RJ Howell]

33hrs on DC power. Best I can tell right now, I'm pushing 40% capacity on my battery. 60ah Lipo4 puts me at about 1.09ah or 36amps used. If I wasn't so busy building the camper, I'd get the electric set up so I could read those amps. I'll get there and confirm.

I hoped to get through the night and have power to spare.. Seems I've got that! Feeling good about this frig!

[bdosborn]

I keep the Waeco running in the garage as the beer fridge when I'm not camping. 33F beer sure tastes good!

Bruce