Just another fridge question

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Hi Darryl,

Firstly I would question the fridge cutout (Battery Monitor) setting. This is the setting at which the fridge will shut down when the voltage (at the fridge) falls below the set value. It can normally be set at one of several levels. The "H" setting will shut the fridge down if the voltage falls below 11.8 volts. If your battery gauge can show a reading of "12v" then the voltage at the fridge may well be below 11.8v and the fridge will shut down until the voltage has risen above 12.6 volts.

While you are driving, the alternator will be maintaining the battery terminals above 12.6v and the fridge will continue to operate normally.

To be sure of the voltage being supplied to the fridge you really need to measure it with a reliable meter right at the Anderson plug while the engine is off.

As above. The fan will keep running so you'll think the compressor is too. Also if your 2 deep cycle batteries are only at 12 volts, they are in a fairly low state of charge so I'd be looking at your charging system as well.

First off is it a compressor fridge?

If the fridge is directly connected to the deep cycle batteries and it runs ok when the cars running then it would appear you have an issue with your deep cycle batteries, the charging system, or a voltage drop as suggested above. Also the charge voltage of 13.5V is low, it would be worth checking why, could be your charging them directly off a low voltage alternator or car has an smart charge setup, could also be a DCDC charger in float charge mode or the batteries are deeply discharged?

The temperature readings your getting, where are you reading them from, I don't understand how the fridge can only be cool if the temperature is 0-1 Celsius are you measuring it with a thermometer?

hi
Compressor fridge ?

Any way , check volt with multimeter at fridge in the first up in the morning .
As mentioned earlier ,does the onboard low volt cut out have a delay [the better LV cutouts do ].
If the cut out is an issue get a Projecta LV cut out [has a delay ] .
Set the onboard unit set at 10.5 v [renders it ineffective basically]

Carrying out these simple checks will get u in the right direction .

This is an ongoing ever repeating issue with caravans and others that travel with fridges.

Lets have a bit of a reality check.

As soon as you say the word "FREEZER" you are talking about a high demand device.
Nothing you can do will change that.

AND if your housekeeping and other management are absolutely top shelf, you will increase the demand of your fridge/freezer considerably. ..... the fridge motor may well running CONtinuously.

Forget any average demand figures the manufacturers publish, they are always very optomistic.

Unless you ABSOLUTELY MUST have a freezzer ... don't ..... if the unit will run as 100% fridge do so. it will reduce your demand considerably.




THEN we get to battery charging ...... people WILL NOT face up to the facts ..... batteries take a significant time to charge ...... the older they get and the harder their life has been the slower they charge.

Unless you have a full days drive ..... I mean 8 hours pluss drive time, you have no hope of fully recharging a deeply cycled battery in a day .... no matter the charge voltage, the available charge current or the charge device or the size of the battery ........ regardless of how you measure "fully charged".

Time and time again, people are running fridges that are TOO BIG, off batteries that are too small, with insufficient recharge capacity and insufficient charge time.

AND ... AND ... if you say the word "FREEZER" it all gets 4 to 6 times worse all round.

A couple of real world examples.

I have a couple of 30ish litre Waecos

If I run one as a fridge and the other as a freezer ...... and this is 2 day prechilled with minimial opening ...... in summer the freezer is flat out lasting over night in summer off a 90 AH battery ....... the fridge 2 maybee 3 days easy.

I have at least a dozen battery chargers here from 1 amp to 30 amps and charge a variety of batteries from 4 to 200AH regularly.

how long a battery takes to charge depends on the condition of the battery and the depth of charge.

I Have had neglected/ abused batteries take 2 and 3 days to charge sufficient for the multistage chargers to drop back to trickle ....... the same battery in good health on the same charger may take 6 to 8 hours to come back form 1/2 charged.

I am currently running my portable fridges in the house as freezers, because the house freezer in on the fritz and the parts won't be available till everybody crawls out from under their Christmass rock.

Adding a quantity of unfrozen ice packs to one of them and it takes 3 to 4 hours to return to -15. .... this is running on mains

the message is all of this takes time and a lot more energy than most people want to believe ...... a big portable fridge is not necessarily a good idea.

AND portable Freezer is not as easy as many people think

cheers

definately got thermo probs.

Similar problem with a Nat Luna Fridge Freezer.
On checking specs I found that they run harder when the temp is set above -9 Deg C.

Appreciate that -18 Deg C would be best but apart from ice cream everything else remains Frozen at -9 Deg C.

So I have decided to work the batteries a little less harder and use the freezer at -9 Deg C particularly when solar production is marginal. oh and add ice-cream to the diet when we are in a CP.

All the other advice here would be relevant also.

Of course Allan