Do I have a problem with my leisure battery or am I just a worrier?

[QFour]

There are quite a few people who claim you can run a 50L Compressor Fridge for a full long weekend on a single 100Ah battery.
What they forget to tell you is they arrive Friday night with a full battery and the fridge loaded with frozen bottles of water, they turn off the fridge overnight and they don't need it by Sunday lunchtime as they are on their way home.

Basically it is as you say .... you have false expectations rather than a battery problem.
You have room for more solar - on a T5.1 SWB you can fit upto 250W and easily have 200W on there. Add to the 100W if you are a summer camper and it will make a difference.
Adding a second battery to your setup will make a big difference. Currently you are just about ok but ending up watching the voltage rather than enjoying the experience. Ideally you would have two matched batteries installed at the same time. With the current one being 2 years old, it depends what the battery is to if it is worth adding one more or remove the current and get two fresh ones. What battery do you have fitted? (make/model)

Be easier to fit a lithium battery. Not cheap but twice the usable energy. Half the weight as well.

 

[Derekoak]

Thanks to everyone for their replies. Very interesting and helpful. For my own benefit I thought I‘d summarise my take out from the posts. Apologies if I’m stating the obvious.

1. It looks like my set up is on the edge of sufficient power ( battery + solar). In my defence I installed a typical set-up that Campervan converters install to run the equipment I’ve got.
2. Given all the changing variables on battery power consumption I can see why people plan on having more than you need rather than the exact amount to avoid voltage watching. - most suggesting about twice what I’ve got.
3. Beware of stated power consumption from suppliers as they may underestimate real life usage.
4. Having a monitor that watches amps and voltage is more useful than one that just watches voltage.
5. Different battery suppliers advise different voltage levels to reflect 50% depletion for AGM batteries (12.3 and 12.1).

If I am to increase my battery power and have limited resources should I
A. Invest in extra 100w solar and buy a second battery and so have a new one and my 2 yr old one ?
Or
B. Invest in 2 new batteries (ie keep solar as is).
Bear in mind my aim is to enjoy the experience and not watch the voltage. We could be parked up for upto 4 days in one spot. ?

If you are parked up for 4 days it will be more solar that saves you. At least in summer. After 4 years we have hammered an 80 Ah Agm with our 70 litre vitrifrigo compressor fridge 120 watt solar. we usually drive a little every day. But now I am fitting 200 ah Diy lithium batteries and faster charging from the alternator.

 

[trevskoda]

You can also get alternators with a higher output if you have a double or treble battery set up.

 

[molly 2]

100 w solar panels can be as cheap £ 60

 

[jagmanx]

As hinted at driving unecessarily costs on fuel ! But that depends on your travelling profile !
In the summer (for 4 months) more solar should really help.
All the expenses will be recouped by both not using camps or not paying extra for EHU .
As posted solar is cheap .
Simple lithium batteries are cpming down on price
How much did yhe vehicle cost ?
Not really asking just suggesting that regard any costs now as part of the original purchase.
We spent £1000 or so on solar and refillable gas 3 years after day 1.
We have saved that x many many many. I think you have enough info to decide what is best and what works for you depends on your "Style".
Ps we had 2 problems with our fridge the other year cost over £150 ..Such is motorhoming !

 

[Snapster]

Iots of of people seem to have compressor fridges and turn them off at night to save power. Do people monitor the temperatures inside the fridge? A fridge, to be working as it should, needs to maintain a temperature of around 6 degrees. But is this possible if the fridge spends a third of its operating time turned off.
Or are they super efficient and better insulated than a domestic compressor fridge?

 

[Derekoak]

Iots of of people seem to have compressor fridges and turn them off at night to save power. Do people monitor the temperatures inside the fridge? A fridge, to be working as it should, needs to maintain a temperature of around 6 degrees. But is this possible if the fridge spends a third of its operating time turned off.
Or are they super efficient and better insulated than a domestic compressor fridge?

I tested our fridge and it depends how full it is. Of course you are not opening the door at night. My test full, got up to 3 degree on a warm night and that was with ice cubes in the little "freezer box". So in winter we switch off, but in summer the time clock is set to come on for an hour at around 2 am.
Maybe with our new lithium we may leave the fridge on . But the compressor makes some noise especially at on and off.

 

[wildebus]

Iots of of people seem to have compressor fridges and turn them off at night to save power. Do people monitor the temperatures inside the fridge? A fridge, to be working as it should, needs to maintain a temperature of around 6 degrees. But is this possible if the fridge spends a third of its operating time turned off.
Or are they super efficient and better insulated than a domestic compressor fridge?

I monitored my fridge temp (surprise surprise ). And checked what happens overnight with power off as well as running normally.
If you turn it off, the temp rises. No surprise there of course. The fridge will automatically come on every 45 mins or so when the temp increases. I found there was a 2 degree variance - so every 45 mins or so the temp would increase 2C and the fridge would come on to drop it down again.
You bypass that by removing power and the temp just goes up and up as the cooling stops.
If it is used to keep drinks cool, no problem.
If it is used to keep food in, uh oh.

The people who turn them off overnight do it because they don't have the infrastructure to run a compressor fridge. They are taking a risk if using for food.

 

[Tookey]

Iots of of people seem to have compressor fridges and turn them off at night to save power. Do people monitor the temperatures inside the fridge? A fridge, to be working as it should, needs to maintain a temperature of around 6 degrees. But is this possible if the fridge spends a third of its operating time turned off.
Or are they super efficient and better insulated than a domestic compressor fridge?

Not scientific in the slightest but its definitely still cool/cold in there when I switch it back on but yes there must be a rise in temp cos the tray under the little freezer bit gets some water in it, not loads but some melting must take place

 

[wildebus]

Not scientific in the slightest but its definitely still cool/cold in there when I switch it back on but yes there must be a rise in temp cos the tray under the little freezer bit gets some water in it, not loads but some melting must take place

One handy check you can make in the freezer part ... Freeze water in a bottle, but only part fill it. Then lay it on its side in the camper freezer and check the next morning the position of the ice-water.
If still at the bottom of the bottle, it stayed below zero;. If frozen, but now on the side of the bottle it defrosted and refroze.

 

[Tookey]

What David said really, I have one battery so turn it off and am just aware that I have to be a tad more careful with food than others, not an issue so far but I do worry about my caviar

 

[Snapster]

we have internal thermometers in our fridge and freezer compartments. I would think they would be useful in a compressor fridge if keeping chilled food at the correct temperature is important.

 

[Derekoak]

We do not eat meat or dairy and little processed food so our problems are less.
When I was young we did not have a fridge, but a cool larder and a earthenware and muslin evaporative cooler for milk, and of course shopped more often. My father was a public health inspector and was very fierce on keeping meat such as pies not hot but warm or rewarming. It was his job amongst others to catch food establishments that did it.

However when milk went off he drank it that day. He said about vegetables you could see, smell, taste if they were allright. Cooked and processed food had 2 days of cool larder and an inspection.
@Tookey I never remember caviar coming up in his advice☺

 

[wildebus]

I posted this a couple of years ago in my Fridge Thread, but might be interesting here to show - for MY fridge - at what points the fridge compressor turns on and off.

So basically the fridge gets to 2C and the compressor kicks on.
Then when it drops down to 0C, the compressor turns off.
The fridge takes around an hour to go back up to 2C and the cycle repeats.

The 0C to 2C range is a little low for a fridge and the thermostat is set too low, but the principle will be the same when the fridge is set slightly higher.


And some usage numbers (again for MY Fridge - but the fridge I got is at the more efficient end of the scale so don't expect to be able to better it much (without turning the fridge off!))
One for running off Lithium and one for running off an AGM (these are usage for a Fridge on its own. Using other things at the time will of course add to consumed Amp Hours)

 

[wildebus]

We do not eat meat or dairy and little processed food so our problems are less.
When I was young we did not have a fridge, but a cool larder and a earthenware and muslin evaporative cooler for milk, and of course shopped more often. My father was a public health inspector and was very fierce on keeping meat such as pies not hot but warm or rewarming. It was his job amongst others to catch food establishments that did it.

However when milk went off he drank it that day. He said about vegetables you could see, smell, taste if they were allright. Cooked and processed food had 2 days of cool larder and an inspection.
@Tookey I never remember caviar coming up in his advice☺

we do not eat meat either (but do have fish, cheese and milk), so the increased cycling of a fridge turned off would concern me less then if used for [meat] food.
I do sometimes wonder if people camping at festivals end up eating contaminated food from their fridge which they let warm up too much overnight, but blame the burger van they may have used over the weekend?

 

[Tookey]

I posted this a couple of years ago in my Fridge Thread, but might be interesting here to show - for MY fridge - at what points the fridge compressor turns on and off.
View attachment 99299
So basically the fridge gets to 2C and the compressor kicks on.
Then when it drops down to 0C, the compressor turns off.
The fridge takes around an hour to go back up to 2C and the cycle repeats.

The 0C to 2C range is a little low for a fridge and the thermostat is set too low, but the principle will be the same when the fridge is set slightly higher.


And some usage numbers (again for MY Fridge - but the fridge I got is at the more efficient end of the scale so don't expect to be able to better it much (without turning the fridge off!))
One for running off Lithium and one for running off an AGM (these are usage for a Fridge on its on. Using other things at the time will of course add to consumed Amp Hours)
View attachment 99300

View attachment 99301

Thanks for posting that David as I now think my fridge is cycling much faster than it should which probably needs some investigation

 

[wildebus]

Thanks for posting that David as I now think my fridge is cycling much faster than it should which probably needs some investigation

It does vary depending on ambient temp. Sometimes my fridge would go over an hour between switch ons, and other times be much shorter.

 

[mark61]

Never turned the fridge off overnight, but up until the current set up have always had to adjust fridge temp, usually by turning fridge on to higher setting when driving and reducing when stopped.
Have run compressor fridges with just the main vehicle battery, doable if you drive every day but a complete PIA really.

 

[Nabsim]

I am almost always off grid all year round. My 110ltr compressor fridge allows me to have fresh veg for at least a couple of weeks without having to shop plus meat in the freezer. I never turn it off except when it needs a defrost and I wouldn’t be without it. Waeco say it averages 2 amps per hour (48amps per 24 hour) and I would say that is right. I wouldn’t dream of turning my fridge off at night, if you are needing to do that you have a mismatched system.