The great fridge debate

[NAGG]

Early Engels were highly deficient in the insulation department, particularly in the lid. Originals' covers were to help with insulation as well as cosmetic protection. You could put your hand between the lid and the cover, and it would be noticeably cold. Later ones are better in that respect, and the cover, IMO, is mostly for cosmetic protection. my MT-V 45 , running as a freezer, doesn't get noticeably cold between cover and lid. And zero condensation.

has there been any improvement in the insulation of Engels (50mm) sides & 30mm on the lid ?

Turn an Engel off & the temp rises pretty quickly is what I've noticed. ...... I just turned off both the Engel & NL - I'll check them in 2 hours

chris

[ranmar850]

I think the oldest Engels were pretty thin on the lid. Subsequent ugrades saw them get a bit better. But, IIRC, it was really the lid that was the problem. I just remember seeing the insulated covers when they first came out at a demonstration, and putting my hand in between, you could really feel the cold it was keeping in. Any insulated cover will aid any fridge with energy consumption, as long as it does not interfere with airflow to the condensor.

[NAGG]

Well the National Luna fridge arrived this morning & it's certainly an impressive piece of kit - Attachment 124164 Nicely finished & the stainless steel used will certainly not show marks easily . fitting are stainless steel with glass filled polyamide (Nylon) corners ,handles & hinges - good solid plastic baskets Attachment 124165

For 40lts it's certainly looks much bigger than an Engel ... confirmed (footprint 0.240 sqm vs 0.227 sqm) - no Waeco / Dometic 40lt these days - but the CFX3 45lt is bigger at 0.276sqm (to be expected)

Good layout in the interior & as you can see from the photo - takes my 10lt jerry can which I freeze for my Esky . Attachment 124163

OK what is really impressed me was the turbo boost which took the fridge from ambient 18 deg to Zero in 20 mins - dropping it to -20 deg C took 13 mins (without the boost) ..... power consumption when running is about 3.5 amps ( boost is 5 amps)

It's reasonably quiet ..... a little louder than my old CFX40 but much quieter (without the vibration) of the Engel .

I'm now testing how long it will take to freeze a 1.5lt freezer gel filled bottle which I generally take on camping trips . (6 hours )

Anyhow ... lets see if it proves itself over time - but I plan to run it continuously for the next month on a mixture of 240 & 12 volt (probably let it spend some time in the canopy to get bumped around - once the cover arrives.

Looks to be a good buy

Well - I'm rapidly approaching two months ...... mostly running on 240 vlt & it is going well .

Last week I decided to run it off my 100amp Lithium battery to see just how long I can run this thing on 12 volt before the battery is drained. I know having a fridge inside in winter is hardly a big ask - so I set it at -10 deg C ..... & then a couple of days in put a 10lt spring water bulk pack in to freeze ( That makes sure the fridge has to work) _ Just ticking over 72 hours now with the battery sitting at 12.9 volts .

I'm pretty happy with those results as I'm trying to get to around 150 hours on the one 100amp battery ...... that's one step closer to not needing to take a generator with me on my Whitsundays trip.
After I run this test - then I'm going to crank the fridge up to -20 deg C & do the same test ...... that will be interesting.

Chris

[Lovey80]

I wouldn’t expect to get another 75 hours out of the lithium if the battery is that flat.

[disorderly]

I wouldn’t expect to get another 75 hours out of the lithium if the battery is that flat.

I agree...

.voltage.jpg
but voltage, particularly under load, is not a very accurate measure of the batteries SOC..to get a very accurate SOC reading you need a shunt and a display monitor of some description..

This is the one I use..it has a display on the dash and also an app for the phone...

victron app.jpg

[NAGG]

I wouldn’t expect to get another 75 hours out of the lithium if the battery is that flat.

What's your best guess ?

Chris

[NAGG]

I agree...

.voltage.jpg
but voltage, particularly under load, is not a very accurate measure of the batteries SOC..to get a very accurate SOC reading you need a shunt and a display monitor of some description..

This is the one I use..it has a display on the dash and also an app for the phone...

victron app.jpg

I'm no expert on this stuff ... far from it . but I have doubts

LiFePO4 batteries can have a shutoff down as low as 8 volt - My Fusion is 8 volt - Enerdrive is 11.2 volt

My fridge is set at 11.7 volts (low voltage) ..... That's a medium protection setting

So for my test - I'll be running this test till the fridge shuts down .

Chris

[disorderly]

The discharge curve tells all, mate..

voltage drop.jpg

You can see that between 10-20% and 80-90% there is only a minute voltage drop which shows how difficult it is to get an accurate SOC from a voltage reading but the voltage drops significantly after SOC reachs 10 % and voltage will crash from 12-12.5v down to 10v or below if you allow it to fully drain..

[Lovey80]

I would have guessed less than 10 hours if your cut off is 12.8v. Though if you took the fridge off the battery for 10 minutes and see what it comes up to, It’d give a better indication on SOC.

[shakey55]

This may be worth a read for those with lithium batteries or considering lithium

https://www.victronenergy.com/media/...scharging.html


Sent from my iPad using Ausfish forums

[NAGG]

I would have guessed less than 10 hours if your cut off is 12.8v. Though if you took the fridge off the battery for 10 minutes and see what it comes up to, It’d give a better indication on SOC.

Made a boo boo

Last week I decided to run it off my 100amp Lithium battery to see just how long I can run this thing on 12 volt before the battery is drained. I know having a fridge inside in winter is hardly a big ask - so I set it at -10 deg C ..... & then a couple of days in put a 10lt spring water bulk pack in to freeze ( That makes sure the fridge has to work) _ Just ticking over 72 hours now with the battery sitting at 12.9 volts .

It was 4 days yesterday - (96 hours) not 3 days (72 hours)

OK - It's dead now - the Fridge low voltage kicked in at 115 . 5 hours with the battery sitting at 11.6 volts (tested 30 mins after shutdown)

So nearly 5 days - set at minus 10 deg C - ..... (30 deg below ambient ) At least I now know ..... I'm guessing 4 days use in NQ on the one 100amp LiFePO$ battery.

​Chris

[NAGG]

This may be worth a read for those with lithium batteries or considering lithium

https://www.victronenergy.com/media/...scharging.html


Sent from my iPad using Ausfish forums

One point to note was backflow from low drain electronics

When I installed my 2 x Victron charges to manage the 2 x LiFePO$ batteries (leccy) I made sure that each charger connected through their own breaker ..... this way when not in use (plugged in to 240 volt) - I trip the breaker & there is no backflow to the charger .

I cant remember the exact figure but it's something like 0.5amps ..... that's 12 amps / day In my case - just over 9 days my chargers could flatten my Batteries & another couple of days we could permanently damage them

Certainly food for thought.

Chris

[Lovey80]

Made a boo boo



It was 4 days yesterday - (96 hours) not 3 days (72 hours)

OK - It's dead now - the Fridge low voltage kicked in at 115 . 5 hours with the battery sitting at 11.6 volts (tested 30 mins after shutdown)

So nearly 5 days - set at minus 10 deg C - ..... (30 deg below ambient ) At least I now know ..... I'm guessing 4 days use in NQ on the one 100amp LiFePO$ battery.

​Chris

Am I reading this correctly? You got another 20 hours from 12.9v until the shut off at 11.6v?

[NAGG]

Am I reading this correctly? You got another 20 hours from 12.9v until the shut off at 11.6v?

So yesterday morning at around 10am - it reached 4 days (12.9V) ...... & shut down at around 6 ish this morning ...... so basically yeh 20hrs

Chris

[Lovey80]

So yesterday morning at around 10am - it reached 4 days (12.9V) ...... & shut down at around 6 ish this morning ...... so basically yeh 20hrs

Chris

i think I was pretty close then. Once below 12.8 it would deteriorate rapidly.