Battery Current Saver (BCS) from VGR Electrics

Mike, for once I have to give you some good advice. I have a BCS unit controlling our 80 ltr Waeco. Without it connected we get 1 day out of the battery in hotish conditions but with it in line we get a full 2 days. The reason being that the startup of the fridge uses much more energy than just running so by limiting the starts per hour you extend battery life. Sure, the fridge temperature might cycle though a wider range but who cares if the beer is 3 degrees or 5 degrees. The freezer stays frozen due to the mass of cold stuff.
I have the fridge running normally (without BCS) while driving but connect the BCS when stopped over night.
Believe me it works and works well.
Ian Hocking

Hi Ian

>The reason being that the startup of the fridge uses much more
>energy than just running so by limiting the starts per hour you
>extend battery life

A normal induction motor will certainly have a high startup current compared to its running current however with the light load of a fridge compressor that will be for a very short period of time hence the _overall_ energy used will be small, additionally I understand Engels use a "swing motor" which doesn't incur high startup currents.

As for fridge temperature; the VGR website quotes a high of 8C - I believe it is essential to keep food at 4C or better to avoid rapid bacteria growth.

A quick Google also reveals this post from four years ago:
Link to Ex Oz post

If you're happy with beer at 6C or 7C and don't keep food in the fridge then just turn the fridge thermostat up a bit.

Additionally a time based controller cannot take into account changes in the system load ie. putting warm stuff into the fridge, unless you constantly attempt to manually adjust it - the standard fridge thermostat will do that for you.

Mike Harding

Mike, I understand all that but the BCS does extend the battery life and that is a fact. It is also a fact that fridge temp is not as constant as it would be without the BCS but it certainly stays around the 4 deg if you set the timer to run correctly which takes a bit of practice.
The timer gives the option to have one startup in each 45 min period and will run for how ever long you set the timer but I find about 7 min in 45 will keep everything at about 4 degrees. Mind you we don't have kids onto the fridge every ten minutes.
I feel you still won't believe it but TRUST ME, it does work.
Looking forward to your words of wisdom on all other things electrical.
Ian Hocking

I'm sure a BCS unit will save power as it is keeping the fridge warmer than the standard thermostat would ever let it get simply meaning for a considerable period of time the fridge isn't running.
As you say Mike fine for some drinks but for milk or meat I wouldn't feel confident that it's being kept fresh. The only fridge I would see this unit being compatible with is the Autofridge that has Eutectic fluid to maintain the temp below 4 degrees over long periods with the compressor turned off.
Cheers Craig..............

Ian

I have had and run one for about 8 years now and agree they work, and it is much easer to manage the ruining of the fridge.

food spoil not so far..

Cheers

Richard

Thank you Richard.
It seems hard to convince those who DON'T have one that they work. I used ours for 3 weeks on the cape last year and no one got sick. Funny that.
Crackles, It doesn't "keep the food warmer", it just cycles between 3 & 5 degrees instead of 3 & 3.5 degrees for twice as long before the battery suffers but anyway if you don't have one and haven't used one how could you know?
It could not care less whether you use one or not. I was just trying ti help.

Ian you said it yourself, without the unit the fridge gets up to a maximum of 3.5 degrees. With the BCS it gets to 5 degrees & according to the VGR website as high as 8. Is that not warmer? You've convinced me it saves power, no argument there! I may not have one but it's the same principle my Autofridge works on of which many owners use timers to minimise cycling.
Cheers Craig..............

Crackles, if you want it to remain colder just run the fridge for longer in the 45 min window, say 12 min in 45 then it will but I find on a typical day that about 7 min is enough. Any way, I tried to help but can do no more. Whether you like it or not it works.

Of course it works but..........I like my beer cold !!!!!! No more than approx 2 degs...

Camping doesn't have to be a compromise ??? you can have your cake and eat it too !!!!! Bigger batteries !!!!!!!

But if thats all you can afford, then thats OK as well....

I used to struggle with cycling the beers thru a 3 way fridge before seeing the light and getting a Waeco, but can understand peoples reluctance to spend money on a system that works !!

Of course you will save power if you keep your food and drink at a warmer temperature, but -

1. I don't want to risk my food going off by storing it at a higher temperature.

2. I could achieve the same result by turining up the fridge thermostat - without wasting money - without reducing system reliability by adding another device in series.



There are better ways to save power - putting a towel or blanket around the fridge will recuce power significantly.

I'm sorry I tried to help with advice gained from experience but there is no helping those with closed minds.
I'll say it again........IT WORKS!!!!!!!!!!!!!

It's sad to see people who can't stand opinions contrary to their own being expressed, without falling back on emotional statements, rather than sticking to the issue being discussed.

Ah Ian… don’t be grumpy with us :)

We’re not having a go at you but simply trying, perhaps poorly, to explain what is going on.

When you use this device to control your fridge you observe the fridge uses less energy from the battery in a given time – I accept that as correct. The reason it does so is that the fridge is getting warmer that it would if the thermostat were controlling it. You could achieve the same result by turning the thermostat up a couple of degrees.

Consider another scenario: it’s been a 30C day and your fridge has been cycling for 10 minutes per hour (or whatever) and maintaining a temperature around 5C. Night comes along and the ambient temperature drops to 10C – unless you reduce the 10 minute per hour cycle to, maybe, 3 minutes your fridge temperature will fall to well below freezing because you are now putting too much energy into it. In reality what probably happens is that the thermostat cuts in and try’s its best to do its job.

By using this device you turn a “closed loop control system” into an “open loop control system” and you must regularly adjust it to maintain optimum efficiency.
Have a look at this link:
Open loop control

Mike Harding