100 Watt solar panel testing - Goal Zero, Rock Pals, Aims Power, and another cheap Chinese one from Amazon.

[shade]

Yes,
Because it’s not squatters to relate to a 100ah battery as 100ah capable for static energy source for a fridge.

It will be insufficient for the spike needed to start the fridge’s compressor even when the volt is within cutoff values.

It’s not just the volt, but the current is more relevant.

That’s another issue why I’m trying to understand how you manage these great results from a standard battery.

If a battery can start my truck, I'm pretty sure it can start a small fridge compressor, especially if the low voltage protection hasn't been tripped.

In this case, it did start my truck, it did start the fridge compressor, and the fridge's low voltage protection had not been tripped - I set mine to the least aggressive setting. How many amps do you think it takes to overcome the startup spike of a compressor? I doubt that threshold is nearly as high as you believe, which is why I continue to say that not being able to run a fridge overnight indicates a problem. Another variable came to mind. To minimize voltage drop, my fridge is on a dedicated circuit of 10/2 wire, which was another advantage over other installations that rely on whatever OEM wiring is available.

I've also acknowledged that I abused the battery during the 2.5 day period in question. My truck starts easy, and it's possible there was only a few seconds worth of cranking power remaining at the end. Without data, I'll never know.

The main takeaway might be that there are ways to minimize power consumption by a fridge, and they can extend the endurance of any battery.

• Keep the fridge ventilated
• Utilize shade
• Install a useful cover - black ones may do more harm than good
• Put the fridge on a dedicated circuit of heavy gauge wire
• Keep the wiring as short as possible
• Minimize time that the door's open
• Make sure the battery is fully charged before a long period of use without charging
• Don't charge other devices off the battery
• Keep the fridge full
• Pre-cool the contents when possible

And most importantly, always bring a jump pack.

 

[dwh]

The (formerly) Danfoss / (now) Secop DC compressors are variable-speed slow-start.

https://www.secop.com/solutions/application-detail/portable-cooling-boxes/

 

[rayra]

So the fridge could not start up with just a solar panel it needs the battery for the startup spike. Does the startup spike prevent the battery from starting the fridge at night if the battery amperage is low? Since this startup spike is only momentary does that mean it has very little effect on battery SOC but only the ability to start as the battery SOC is reduced?

I think you are mixing up voltage with amps. They are interrelated but not the same thing, in the way you seem to be thinking about it. 'SOC' / voltage reading and low voltage cutoffs are a different aspect than ability to deliver peak amps. Yes, a drawn-down battery can't deliver a max rating amp flow. But the relationship isn't linear.

/that's how I understand things, I might be wrong.

 

[Photobug]

I think you are mixing up voltage with amps. They are interrelated but not the same thing, in the way you seem to be thinking about it. 'SOC' / voltage reading and low voltage cutoffs are a different aspect than ability to deliver peak amps. Yes, a drawn-down battery can't deliver a max rating amp flow. But the relationship isn't linear.

/that's how I understand things, I might be wrong.

That was basically the question I was asking is how does a drawn down's battery affect its capacity to deliver amperage and or a startup amperage spike. Until I get another vehicle or a trailer I have nowhere to store a fridge, so it is just for educational purposes.

It sounds as though there is two options for a fridge not working.
1. low voltage shutoff turns off the fridge.
2. Amperage spike may cause the inability to start up?

Not sure about the last one, but since every thread about fridges brings up the amperage spike. I assume this startup spike has to affect something.

 

[DorB]

voltage reading and low voltage cutoffs are a different aspect than ability to deliver peak amps. Yes, a drawn-down battery can't deliver a max rating amp flow. But the relationship isn't linear.
.

Correct.
The volt can be in the cutoff range, and the fridge would turn on but the current (amp) is not sufficient, and the compressor will not start.

Common failure that has similar Symptoms are faulty/insufficient negative (-) connection, or thin wiring.
Both will lead to fridge cutoff even though the volt/amp are sufficient.




Slowly..

 

[PSea]

The main takeaway might be that there are ways to minimize power consumption by a fridge, and they can extend the endurance of any battery.

• Keep the fridge ventilated
• Utilize shade
• Install a useful cover - black ones may do more harm than good
• Put the fridge on a dedicated circuit of heavy gauge wire
• Keep the wiring as short as possible
• Minimize time that the door's open
• Make sure the battery is fully charged before a long period of use without charging
• Don't charge other devices off the battery

And most importantly, always bring a jump pack.

...and keep the fridge full to make it even more efficient. too much extra space? freeze water bottles.