Dumb question about a Goal Zero Lithium 500X and National Luna 50L Legacy Fridge/Freezer

[ChrisCosta416]

Hi all,

I have been scratching my head at this trying to solve it.

My "solar" setup is currently a 100 watt solar panel, Goal Zero Lithium 500X powering a National Luna Legacy Fridge/Freezer.

Currently connected to the fridge via 12V cigarette lighter (goal zero) to DC input.

However when using the fridge/freezer combo (after both the goal zero (fully charged) and fridge (pre chilled days prior) in my vehicle it does not last a whole 24 hours. Parked/driving with clear skies and sun out

The output for my fridge (when the compressor kicks on, which is often is 113 watts)

Does any of this sound right? Am I doing something wrong?

I am a total noob when it comes to this stuff.

 

[NatersXJ6]

It doesn’t sound “wrong” to think that would barely last the night. The spec I looked up claims that goal zero unit has 505 watt hours of capacity. Assume that is true, and you can use all of it (both VERY generous assumptions). If the readout is accurate, from sundown to sunup you are consuming 113 watts every time the compressor is on. Thus, 505/113=not very much runtime. Slightly over 4 hours in perfect conditions. Assume a 12 hour night and you can only have a 30% duty cycle. It appears that you need a much bigger battery and probably a smaller, lower draw, better insulated fridge.

 

[fratermus]

I have been scratching my head at this trying to solve it.

It's a power consumed > power harvested problem, as the "Input 45w Output 113W" display suggests. @NatersXJ6 has done the math for you.

Normally I'd say "add panel", but the input limitations on the Yeti are rather restrictive:
Charging Port... 13-22V, up to 10A (120W max)

Options at this point might include

• trying a 150w panel, which would be unlikely to exceed spec in actual use, and/or
• trading for a fridge with a less powerful compressor. 45w-60w is more common, and/or
• building a small DIY system without such input restrictions
• {edited to add: forgo the freezer function - it uses much more power to hold freezing temps}

 

[NatersXJ6]

I sort of agree, my first thought was also “add panel” however…

I’m fairly certain that even starting from a full charge state you are really tight on the margin for making it through the night. Certainly for multiple nights / make it through the weekend, no matter how much panel you have.

That could be tested if you could find a simple timer to put in the fridge circuit and track how long it is “on” each day or even each hour.

 

[ChrisCosta416]

I guess my question is, isn't 113watts kind of high for a National Luna Legacy 50?

• Average Hourly Draw: 0.8 amps (From Expedition Portal)

NL 50 Legacy Stainless Steel Refrigerator & Freezer - National Luna

The NL 50 Legacy Stainless Steel Refrigerator & Freezer is the ideal fridge/freezer combination for recreational users. Discover more about the NL 50 here.

www.nationalluna.com

 

[fratermus]

isn't 113watts kind of high for a National Luna Legacy 50?

Sounds like a question for the manufacturer. The manual doesn't specify power consumption, but does refer to a power placard affixed to the fridge. The manual also has a section describing maintenance to remove dust and crud that may affect performance.

The manual does specify a 15A fuse for 12vdc; that'd be ~180w.

The marketing docs talk about Turbo Mode and normal mode. Perhaps the higher consumption is in Turbo mode.

 

[RangeDrive]

Was this with the refrigerator packed, or empty? That could affect run times. But yeah, the Yeti 500 is really barely enough to run a fridge, without fully charging every day (coming from someone who just bought one). Keep in mind when researching for an upgrade, that all of these solar generators (GZ, Jackery, Bluetti etc) advertise Watt Hrs and not Amp Hours. Something like a National Luna power box with a large amp hour lithium battery, will get you much more power