12v power

If you run an Engel as a freezer I would expect it to use more power than your 80W panel provides.

Remember an 80W panel wiill only charge at full belt for about 4 hours say 80X4 = 320 Watts = 25Amps plus say another 10=35 Amp hours MAXIMUM
The Engel will take probably 2amps x 18hours at say 66% duty cycle 36amp hours

Just a quick calculation shows that you are pretty borderline and any cloud or inefficiency of the panel will mean far less generation, and a hot night more usage.

Check the state of the battery at say 4PM and see if it is fully charged at 12.7-8 volts

I am currently looking at buying a panel and I would only get a 120watt panel using the Engel as a fridge only.
Regards Philip A

Hi Bob,

possible causes are:
battery having lost part of its rated capacity due to long storage.
Try the following remedy: connect your solar panel to it without any regulator and let the panel charge it for a whole day.

Another cause could be a sub standard solar regulator, such as the ones which come with folding solar panels.
These can cause the battery to be under-charged, especially if some load is connected during charging.
None of these el cheapo regulators offer multistage charging, which is so important in a cyclic battery application (cyclic means discharging at night, charging during the day).

If you succeed in getting sufficient capacity back into your battery by the method above, the next step is to invest in a suitable multistage solar regulator - ideally MPPT which can make available about 20% more solar power from the same panel.
The solar regulator also should have battery temperature compensation (with a sensor) to prevent accelerated battery aging in summer and sulphation in winter (sulphation is a gradual and mostly permanent loss of battery capacity).

Just in case your battery is beyond repair, get a new battery and charging gear - in a perfectly matched combination from someone who's doing both (stops the guessing and blame game if something fails within the system).

cheers, Peter

What do you need to be kept frozen?
It all gets much easier when you take along foods that dont need freezing or vacuum packed foods.

Hi. I run a 80lt as a freezer and a 40 lt as a fridge. I will turn my 80lt back to about 2-3
overnight. The temp will drop back from about -17 to -8 overnight in the morning when the sun is up I crank it back up.If a cloudy day I will also ease it back
Cheers Brian

Hi Bob

I did a newsletter a while back on how to test your battery capacity.

Here is the link: Capacity-Test

Regards

Derek from ABR

Hi Bob48, I have 2 engel 40 lts one as a fridge and one as a freezer, I have 2/80w solar panel's and find that if you turn the fridge on to cool and the freezer down to 3 it lasts all night. The battery will be low in charge but they still work. If I'm camped up for awhile then I use the car to charge for the first 15 min in the morning and turn the freezer up to full. Again I only open it a couple of times a day. Hope this helps

This seems to be a re-occuring theme......and across several forums.

There is a vast difference between running portable refrigerators as fridges and freezers.

Running as a freezer at -15C, the same unit will pull 4 times or more as much average power that it would under the same circumstances running as a fridge at +2 or 3C.

As you wind the temperature down you get a double whammy.

the cooling looses due to transmission thru the insulation dramaticaly escilate, that combines with the refrigeration efficiency dropping massivly.

In some situations and some fridges the refrigeration system may not even be able to achieve the target temperature.

for example
If a fridge system has a maximum temperature difference of 45deg C (that is the maximum difference it is capable of producuing between outside and inside the fridge) on a 35C day the fridge is only capable of producing -10C inside the fridge, and then incredibly inefficiently.......set at -15C the example above would run continuosly and still not keep up.
The same unit running at +2C will be capable of achieving its goal temp and its efficiency will massivly better.

Its all about temperture difference......its like trying to fill a bucket with a hole in it.

Forget any published average power consumption figures you may have......they will be optomistic at best.

Rely only on the current consumption figures while the motor is running ( often listed as the maximum current draw)....the duty cycle ( how long the motor runs and how long it is off) will vary wildly depending on circumstance....freezers will run for hour after hour after hour

While most of these compressor bassed portable fridges WILL freeze and produce ice, they are primarily designed as fridges.


The bottom line is realy think serioulsy ..do you realy need to be running a freezer.

There are alternatives, like vac packing.

The other issue is that people have very much over optimistic expectations of solar panels..........Solar panels will only produce their rated output in the highest radiation parts of the country and only in the height of summer and only during the middle of the day.........In some situations the panel may average as little as 20% of its rated ouput over over the daylight day.


If you are running on solar panels...unless you have sufficinet output to fully charge the battery during the day and early in the day.....fiddling with the temp is completly pointless.....because all you are doing is robbing peter to pay paul.

remember the maximum safe temperatures are +5C for a fridge and -15C for a freezer.........If you can not maintain those temperatures realy think about it.
And most beer educated drinkers will think a +5C beer is warm..some goes for anybody who likes any type of COLD drink......+2C is tolerable.

cheers

Thanks for all the info.

I forgot to mention that also run a two zone on top of the engle. Seems to work ok when battery power is sufficient, I dont think that the manufacturers claims of no extra power consumption are in fact correct.

I have also fitted a low voltage cut off switch to the fridge to stop running batteries down too low.

Any further feedback will be greatly appreciated.


Bob

This is the power consumption of your Engel 40L
25C +5C 24% run time .54Ah/Hr 12.96A/24Hr
35C +5C 47% run time 1.14Ah/Hr 27.36A/24Hr
45C +5C 78% run time 1.92Ah/Hr 46.08A/24Hr

25C -5C 52% run time 1.18Ah/Hr 28.32A/24Hr
35C -5C 76% run time 1.75Ah/Hr 42.00A/24Hr
45C -5C 100% run time 2.32Ah/Hr 55.68A/24Hr

25C -18C 87% run time 1.96Ah/Hr 47.04A/24Hr
35C -13C 100% run time 2.25Ah/Hr 54.00A/24Hr
45C -1C 100% run time 2.35Ah/Hr 56.40A/24Hr
Take note of the 100% run time where the compressor never switches off.
Figures courtesy Sunwires.

All portable fridges regardless of compressor brand for the same size physical unit use the same power consumption to achieve the same outcome. If you take a Waeco with the Danfoss compressor or the Engel with the Sawa Fuji compressor, using the same fridge, the power consumption of both will be close to identical. Where the difference comes in is in cabinet quality, seals and insulation.

Many here should take a chill pill especially when it comes to making ridiculous and ludicrous claims.

When I run my Engel off the van battery it consumes 4amps on start up quickly dropping to 3amps after about 1 minute.
The van has a battery monitor that shows what is being used in amps.
The fridge is set at 2% Cel which means it roughly cycles on at 4% C and off at 1%c.
This engel was purchased in 1995 and hasn't missed a beat since.

Lots of talk and good advice but the original question was about "it doesn't charge up fully"
One commonly often overlooked fact with energy coming from a solar panel is the voltage drop between the panel and the charge controller and batter/ies.
All too often this wiring causes a voltage loss because of resistance in the wiring, eg to thin.
Even a very small amount of resistance ( voltage drop) in the wiring (positive and negative wires to the reg and to batt, greatly affects the performance and total energy which can reach the battery.
Yes the Texans are right. Bigger is better in wiring in a solar charge system.
Most people have too small a cables and therefore lose a lot of efficiency.
Battery doesn't charge fully as a result.
I agree with one comment which said the system in question is hardly up to the challenge. More watts, bigger store battery and suitable wiring and things will improve. But it costs money. Please check the wiring size before upgrading anything.

Regards

Ross M

Hi Bob
Back to your problem

[quote[1]..I have an engle 40l. Which I have been running as a freezer when free camping.

[2]I also have a thumper 75a/h battery and an 80w solar panel.

[3]The problem is that battery is not lasting as long as I would have expected. It sometimes Runs overnight.
[4]I also have the feeling that the solar panel is not fully charging the battery during the day.

Could anyone shed some light on this problem, and any solutions.

Regards. end quote


[1] the figures I have posted above give a range of power reqs for differnt conditions
At the very best with the thermo set to any degree of freezing you will probably be using 50plus amphrs per 24hrs
[2]Your 75 amphr battery should not be discharged below about 50% capacity for long life
50% 0f 75 =37.5 amp hrs over 24hrs
[3]as you can see in any one 24hr period [without any charging input] you will have taken the battery below its recommened level just running the fridge Any other loads [lights ,tv etc will further worsen the problem
[4] your 80watt solar working @ it's very best will only replace about 25amp hrs of that used capacity
AS you can see you are going backwards very fast
YOU are taking out 50amphrs & only replacing 25anphrs
Yoare going backwards @ the rate of25amphrs per day
IF you 75 amphr battery is healthy & fully charged it will only last a little over 24hrsbefore it is below the rcommended level


What can you do
Options
Turn the thermostat to the warmest acceptable level.
add what ever you can as extra insulation,
but do not block any of the fridges ventilation areas
But those will only have a minor effect.

YOU need more means of charging
solar panels, generator,
To run an Engel or Waeco as a freezer [but not at max deep freeze] you do need at least 200watts of solar& they need to be in full sun for a min of 6hrs per day
You also need overnight & poor weather battery backup again around 200amp hrs, even that it is an absolute mIn INMHO
You will get caught @ times

People often under estimate or are mislead on the power requirements of compressor fridges
Many choose to remain with 3ways for this reaon, running on gas when away from mains power

GIVE the above some thought ,if any further questions just come back

Peter