METER READING NORMAL?

didi · Senior Member

METER READING NORMAL?

Peter_n_Margaret · Guru

It appears that the fridge ran from the battery.
Maybe the 240V was not turned on?
Maybe the fridge is not connected to 240V and maybe the charger was not turned on (if it has one)?

Cheers,
Peter

SnowT · Guru

as peter said...

Actually a reading of 12.3v means that the setup could cause some issues... 12.3 is a low leading @ 50% usage and if that just from the fridge.. your in trouble...

I don't know the setup you have.. butt running the batteries down to 12.3 or lower Don't expect your batteries to last longer than 18month's.. the minimum that that the manufacturer stated...

Hope the battery Ah is greater than 100ah..

juergen

-- Edited by SnowT on Saturday 7th of February 2015 10:54:55 AM

didi · Senior Member

Probably wasnt clear. i left the frige on overnight with no power supply. volt dropped from 13.5 to 12.3 . is this normal? Brian(Briche on here) did set up for me so all good. redarc isolator a nd ctek regulator to 12v house battery.

woofta and precious · Senior Member

If the fridge compressor was on at the time, it would probably give you that reading under load, even if the battery was in good nick.
Brian

didi · Senior Member

Sorry woofta. not a techie myself. you said if fridge compressor was on? Di you mean if fridge was on? and under what load? sorry

woofta and precious · Senior Member

Hi didi,
Yes, I mean when the fridge thermostat cuts in when the fridge temp rises above 2 degrees or whatever you have it set on.

Then the compressor turns on to cool it down to the desired setting and it cycles on and off the entire time.

Depending on what the ambient temperature is, dictates the number of times the compressor turns on and off.

If you checked the battery voltage when the compressor was on, it would read less, as it is under load.

When the fridge has cooled down, and the compressor is off, there is minimal load on the battery and it would probably read 12.7 or 12.8 volts in your case.

I am no tech either, but that is my understanding of how it works, but I am open to correction if I am wrong.

Hope it helps.

Brian (woofta)

PeterD · Guru

Di, battery voltage varies considerably as you may have gathered by now. The voltage is dependent on the type of battery you have to s small extent (you did not specify the battery type you have.) If you go to this page you will see some tables for the three main types of battery we use. The table gives the voltage you would expect for different states of charge after the battery has rested for a few hours without any load on it. If the battery is in use at the time you measure the voltage you should expect the voltage to be a little less.

If a battery is on charge the voltage will be much higher. The 13.5 V you saw after removing the mains power would be the float voltage across the terminals before the battery dropped to a level where it would be without the charger on. Do you remember what the voltage was whilst the battery was being charged? When you commence charging a battery the voltage will rise to a level where it will be constant whilst the last 10 to 20% of charge is being received. This voltage depends on the type of battery, the time taken to reach this voltage depends upon the initial state of charge and size of the charger. When the battery is charged the charger will reduce its output voltage to a float charge level in the range 13.3 to 13.8 V depending on the battery type. When you switch off the charger the battery will have what is called a surface charge. This surface charge will dissipate over time to normal battery resting voltages. Again the time will vary and that depends upon how much load is on it.

I hope this will help you understand what you have been observing.

didi · Senior Member

Thank you everyone. yes I have discovered it is the fridge which is on all day and night which runs the battery down. When I turn the fridge off the voltmeter shows a higher charge. nothing wrong with the solar . That is working fine. As I and travelling in hot weather now the fridge is working harder. I have been stationary for a couple of hours now and just turned my rfidge off and the voltmeter shows 13.1 Nothing else I use drains the battery.
I need something to cool down my fridge- a fan or something. Or Ive been told an Engel fridge doesnt use as many amps.
Cheers for all your help Didi

Baz421 · Guru

didi wrote:
Thank you everyone. yes I have discovered it is the fridge which is on all day and night which runs the battery down. When I turn the fridge off the voltmeter shows a higher charge. nothing wrong with the solar . That is working fine. As I and travelling in hot weather now the fridge is working harder. I have been stationary for a couple of hours now and just turned my rfidge off and the voltmeter shows 13.1 Nothing else I use drains the battery.
I need something to cool down my fridge- a fan or something. Or Ive been told an Engel fridge doesnt use as many amps.
Cheers for all your help Didi

So this confirms what Brian says and I agree. I have a 50L Waeco in the tug and the usual current draw is normally 4-5A for a well charged battery and up to 6A as the battery voltage decreases significantly to say 12.5 - 12.2 ish and below.