Connecting a 12v Coolbag

[StuartO]

My beloved wife has an endless appetite for fridge capacity and one way of pleasing her would be to carry a 12v coolbox, so that she can expand her cool storage when necessary.  I realise that a coolbox is a poor substitute for a second fridge but it will at least provide some additional slightly cool storage.

 

I'm therefore looking to connect a coolbox so that it will be powered only when the engine is running and/or when solar power is sufficient to sustain it without battery drain.  So I need to where on my 2006 Hymer's Schaudt Electroblock EBL101 (to which a Schaudt Solar regulator is already connected) to draw the power supply for a 12v socket for a cool box?

 

I have the requisite socket, cable and connector pins.  Does anyone know which spare connector holes on the EBL would serve this purpose?

 

[PJay]

I have a 12v cool box, which on occasions I have used in van. I find it useful for keeping salads and fruit cool, leaving space in fridge for the meat/milk type goods that do require cold in in Spain.

The 12v box ( as like the fridge on 12v) will only keep cool, not frozen I have a longish lead, so plug in to the nearest plug Personally i don't think it worth carry around. Ok for picnics I Guess, or keep beer cool if filled with ice cubes

 

PJay

[Alanb]

My wife also has an appetite for fridge space, so many years ago we purshased a coolbox. It is used most at the start of a trip so that we can leave with more fresh food. Joyce supplements the cooling effect with pre-chilled freezer blocks, which when space allows can be re-chilled in the frozen food compartment of the fridge. On the whole, Joyce considers the coolbox useful.

 

I cannot advise you directly on the Electroblock as I have not used one. However if you Google "A'van for Manins", Peter Manins has included a diagram of an Electroblock on his site. Perhaps that may be of use, or do you already have a digram?

 

In general terms I would be rather sceptical that you could simply achieve your desired aim of allowing the coolbox to run when your solar panel output will float the load applied by the coolbox. (In the region of 4 to 5A, if I remember correctly. You would have to quantify the solar panel output and then trigger a control relay for the coolbox

 

I have installed a dedicated socket for the coolbox in the boot of our PVC. I have used a micro automotive relay and some simple logic so that the coolbox is only powered either when the engine is running (simulated D+ live), or when on EHU (charger signal connection live). A facility to make the coolbox socket continuously live is included.

 

Alan

 

 

 

[StuartO]

Alanb - 2017-03-30 1:31 PM....In general terms I would be rather sceptical that you could simply achieve your desired aim of allowing the coolbox to run when your solar panel output will float the load applied by the coolbox. (In the region of 4 to 5A, if I remember correctly. You would have to quantify the solar panel output and then trigger a control relay for the coolboxI have installed a dedicated socket for the coolbox in the boot of our PVC. I have used a micro automotive relay and some simple logic so that the coolbox is only powered either when the engine is running (simulated D+ live), or when on EHU (charger signal connection live). A facility to make the coolbox socket continuously live is included.Alan

 

I always envy people who are sufficiently electronically capable to create a one-off gadget to solve a control problem!

 

[pepe63xnotuse]

Stu'..

 

If your van's freezer compartment is up to freezing down bottled water, freezer blocks etc, what about just using a decent quality coolbox (Coleman xtreme or Igloo maxcold)?

 

(When we'd use our 12-15 year old Igloo coolbox, after 2-3 days use out in a tent, there would still be large chunks of ice in the pre-frozen water bottles..and that was without any "replenishing " from a freezer).

[Alanb]

Hi Stuart,

 

It has occured to me that your motorhome may well be one that shuts down the 12V electrics when the engine is started.

 

There was a recent thread on this subject started by Allan of Aandacaravan Services. This could make it difficult to power a coolbox from the habitation battery.

 

One simple answer would be to power the coolbox from the Fiat 12V power socket on the dashboard. This socket is switched off with the ignition, so it would be difficult to run down the vehicle battery.

 

I have studied a diagram for an Electrobloc EBL 269, which may not be what you have, but it reveals the possibility of connecting a socket for your coolbox to Electrobloc socket that is intended for the connection of an "Auxilliary charging unit". The socket would be permanently live, and the coolbox would take power from your habitation battery if there was inadequate solar input or no EHU connection.

 

I have also considered adding a voltage sensitive relay, but again I can see possible problems when solar panel output is insufficient to supply the coolbox.

 

The method that I adopted of supplying power to the coolbox when the engine is running, or when on EHU would seem to be possible with the Electrobloc. It would require a minimum of a small relay with the coil supplied via two blocking diodes.

 

Alan

 

 

[colin]

A decent coolbox works surprisingly well, we used one for our main refrigeration in van for several years, ours had a 'undervolt' switching unit to ensure it never ran the battery too low, it had two settings first if connected to a leisure battery, second if connected to starter battery, this would I think suit you, I think it was made by Waeco. Looking around it seems the latest version is a bit more basic.

https://marinestore.co.uk/Merchant2/merchant.mvc?Screen=PROD&Product_Code=WA9105303854&Category_Code=marine-battery-chargers-and-inverters&Store_Code=mrst&gclid=CLOmpeuB_9ICFYQy0wodg0sFVg

[StuartO]

I've been rather hoping that AandACaravans would pop up and respond to this thread, but he must be a bit busy; he's obviously the guy to help.

 

My Hymer doesn't shut down the habitation electrics when we're moving and so the frdige continues to run on 12v while stationary, so you have to remember to switch to gas.  This is not a problem for us.

 

Alan (AandA) mentioned in a previous post that it is possible to change this setting so that the frdige supply disconnects when the engine stops, simply by pulling a fuse.  I may therefore be able to connect the coolbox supply to wherever the fridge would be supplied from in this mode, once i know where it is.  Having the solar supply kick in to help when it can might turn out tyo be unrealistic but we'll see what Alan says.

 

Thank you everyone for the comments about whether coolboxes are useful or not, but my interest is in the electrical supply. 

 

[colin]

I'm not sure you quite understand my posting, with the correct undervoltage protection such as the device we had it will all be automatic and just a plug in device.

I've just remembered that the one we had cut the consumption of coolbox to 1amp at a certain voltage before shutting down completely, so the impact on the leisure battery was cut to a minimum, we could keep it running with a 30w solar panel

I note that with a divice such as this connected inline https://www.amazon.co.uk/Adjustable-Under-Voltage-Monitoring-Relay/dp/B00OK41KXS you could set it to cut out at say 12.5 volt and it will do all you want, having the coolbox only operating whilst the engine is running may well leave it ineffective.

[StuartO]

Got it - I think.  I connect from the leisure battery (by choosing a relevant output on the Electroblock) and a low voltage protection device on the cooler supply would ensure that it only drew power when the leisure battery was being charged by something.  The little Waco device looks ideal.  Thank you.

 

[colin]

StuartO - 2017-03-31 12:42 PMGot it - I think.  I connect from the leisure battery (by choosing a relevant output on the Electroblock) and a low voltage protection device on the cooler supply would ensure that it only drew power when the leisure battery was being charged by something.  The little Waco device looks ideal.  Thank you.

The only thing I would say is the latter Waeco devise doesn't seem as sophisticated as the one we had and will only cut out at 11.6v, and will only start again at 12.8v i.e. when the engine starts or the solar is kicking out a good charge. It will prevent the leisure battery getting too low, but it might leave you short of power for watching tv in evening, the Amazon device can be set at say 12.5v (or even higher) which will mean you shouldn't run any chance of being compromised on power.If you can find one of the older Waeco's with a sliding switch you will find it much more useful.

[Alanb]

Hi Stuart,

 

Colin semms to have posted before me but may I also advise against using the Waeco device in your intended application, for the following reasons.

 

The quoted Cut-Off, and Cut-In voltages are TOO LOW!

 

I always understood that a voltage of 11.8 volts was a flat battery. Information posted on this site by Aand acaravans suggests going below 12.2V or even higher can seriously reduce battery lifetime.

 

The Cut-In voltage of 12.8V would be too low to confirm that the battery is being charged.

 

The alternative GINRI POWER AUTOMATION device from Amazon suggested by Colin is an attractively presented piece of kit, and comparatively easy to adjust. However there appear to be two quoted current ratings for the output relay contacts. The text states 2.5A, which is too low for the average cool box. However on magnifying the illustration the device itself is marked at 5A which would be OK, but which figure is correct?

 

A less expensive alternative is available via Ebay, not as pretty to look, or as easy to adjust, but with an adequately rated output relay.

 

I did not previously expand upon the voltage sensitive relay method, because as I said I could forsee problems. These relate to the unit repeatedly cutting IN and OUT as the battery voltage rises and falls, when there is insufficient solar input. Given Colins experience, perhaps I was too pessimistic!

 

As regards a suitable connection point the only diagram I have available is for an EBL 269, but it is probably generic. You state that your MH does not shutdown the 12V electrics whenthe engine is started. On this basis as well as block 3 (auxilliary charger) you could also use, if available, the "spare" output on block 7 pin 9 +ve and pin 5 -ve. This output would be subject to the main 12V power switching.

 

Your refridgerator taking 12V power when the engine is not running, suggests that the fridge is connected to the compressor/AES fridge output at pin 2 of block 1. The 3 Way fridge output is at the adjacent pin 1.

 

Alan

[John52]

I could not see an ideal way to do this. So I just plug mine in to the leisure battery and it has a short red led strip that lights up when its plugged in to remind me its on - uses very little extra power http://www.ebay.co.uk/itm/4-X-5050-LED-Strip-Light-12V-Car-Van-White-Blue-Red-Green-Warm-White-10-30-cm-/262729654098?var=561668302292&hash=item3d2be85f52:g:V3AAAOSw44BYM-rh (select red colour and shortest length)

[aandncaravan]

Stuart, sorry I have been on holiday in the van for a long weekend to the Tacla Taid Caravan club CL site that is also a 100+ Vintage vehicle museum, Cars, Motor bikes, Tractors, Military, etc.

 

Lovely couple and they let my 6 year old sit in the 1938 Fire engine and the Scorpion Armoured Car, made his weekend.

 

 

But back to the EBL 101 where you have a few options.

 

First may I point out that the EBL 101 (like the 226, 220 and 100, etc) is one of the units that calculates power remaining in the battery, for which it must control all charging and discharging. Nothing must be connected to the battery directly otherwise the DT xx display readings can be a nonsense and even cause the EBL to shut down so, better explanation on the Solar Power pages : http://www.aandncaravanservices.co.uk/lr-1218.php

I know you already know that, it is for the benefit of others following the thread, maybe at a later date.

 

I assume the vehicle is fitted with a 12v Compressor Fridge so powered from Pin 4 on Block 1? This is the Pin that gets 12v when the Alternator is spinning plus 12v direct from the EBL habitation battery input if the second fuse holder from the left, 'AES Fridge' is populated, which you refer to earlier. This will happen even if the Alternator is not rotating.

 

Pin 1 on Block 1 is the conventional 'Absorption Fridge' power point that is only powered when the Alternator is 'active'.

 

So one option, is to move the Compressor Fridge to Pin 1 and run it like most other vehicles run the Fridge, and use Pin 4 to power the Cool Box.

In this position the Coolbox will get 14v Solar power, Alternator and direct 12v from the habitation battery when the 'AES only' fuse is inserted.

 

Option 2 :

Assuming you have a late model EBL 101, like a 'C' version, you have 25amps available on Block 5 at Pins 1 and 4 (maybe use both pins to spread the load as although the power is often only 6 amps it may be 'on' extended times) powered via Fuse 'Spare 4A'. Negatives available on 5 and 10.

 

Option 3:

If that is already being used, there is up to 25a available on 'Fuse Spare 3' (Block 5) at Pins 2 and 3, again use both pins to spread the load?. Negatives at pins 7 and 8.

Note this 'Fuse 3' loses power if you turn off the Control Display/EBL using the switch above the door.

 

 

The AES fuse point and Block 5 pins 1 and 4 are powered by the habitation battery and Solar even when the motorhome is shutdown, but loses all power (including Solar) when the EBL 'front Ein/Aus switch' is 'off', pushed in at the bottom.

 

 

Edit, sorry wrong about Block 1 Pin 1 and 4 on the EBL 101, it is different to the ubiquitous EBL 99, EBL100 both Pins are wired internally from the same point so it would require a mod to the EBL 101 to use this functionality so your best bet is option 2 or 3

 

 

 

 

 

 

 

[StuartO]

Excellent, many thanks. Good to hear you had a good weekend. S

[StuartO]

Another question for you electronic buffs:  I know where to draw the solar/leisure battery power from but I still need a low voltage disconnect device, to ensure that my cool box is only powered when there is sufficient generation, either alternator or solar panels.  So how about using one of these from EBay:

 

http://www.ebay.co.uk/itm/282406046873?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

 

[StuartO]

And another question for Alan: what is the pin numbering for Block 5 on the EBL please?  There are no numbers on the Block 5 socket.

 

I have the correct sixed pins but no plug - do you stock these?

 

[aandncaravan]

On the EBL101 Block 5 starts with 1 at the bottom left and goes across to the right. Then the next row up is , from left to right, 4 5 6, then up and from the left 7 8 9, etc

 

So looking from the front at BL5 it is :

 

10 11 12

 

7 8 9

 

4 5 6

 

1 2 3

 

We don't normally supply parts like this, but as you have helped me so much in the past I will see what I have.

Please can you send me your postal address using the email address at the bottom of the Home page : http://www.aandncaravanservices.co.uk/ or the 'Contact Us' page Form?

 

 

 

 

 

[StuartO]

Many thanks - are we talking top and bottom as in the way the EBL101 label on the front reads?

[aandncaravan]

Yes, sorry I forgot some are mounted upside down!!

 

See attached photo, where at the bottom left of block 5 is a 1 with an arrow pointing in the direction the digits increment.

 

It is a strange numbering system because if you look at the photo below, Block 1 and 2 both have Number one pin at the top with the digits incrementing as you drop down.

 

You can check you have the right pins by looking for a voltage that drops when you remove the relevant fuse. So Pins 1 and 4 should lose power when you remove fuse 4A.

 

Although this circuit will support 25amps, obviously a smaller fuse will provide better protection, so run with a fuse that is about 20% more than the peak power you will be drawing.

 

One last thing :

Last year we were contacted by someone who wanted to run their Drinks Coolbox on Solar and as an auxiliary Fridge. They calculated the Solar amps available would run the Coolbox, but it didn't work well.

 

They forgot that the Solar Array was already charging the batteries up from the previous days TV, lights, water pump, etc. and only just managing to put back each day what was taken out the night before.

 

[StuartO]

Very helpful, thank you.  I doubt I would ever have spotted that pin numbering system on my own!

 

Your comments about the limitations of solar power to run a coolbox are of course perfectly valid and since we only have a modest solar capacity - about 130 watts - if we are off EHU then unless we are driving we probably won't have enough to run the cooler on those days, nor of course overnight.

 

Hopefully we'll get some cooling this way and using a low voltage disconnect device will safeguard the battery.  Hopefully the low voltage disconnect will arrive from latvia in time to fit this up befoe we leave for France.  I'll let everyone know whether it works or not in due course.

 

[StuartO]

Bit of a follow up.

 

My low voltage disconnect device off EBay (£23) arrived fairly quickly from Latvia so I installed the power supply yesterday.  I connected the low voltage disconnect to the Electroblock using Alan's guidance and then ran the output to a Hella-type 12v socket, to which I will connect the cool box when required.  I set the low voltage disconnect to the maximum allowed of 12.5 volts and the reconnect at 0.5 volts, the aim being to avoid discharging the leisure battery while leaving the coolbox connected continuously, to take advantage of alternator, solar and EHU power when available.

 

Hopefully this will work as intended, disconnecting the coolbox when we're running on battery alone - or at least as soon as its voltage drops to 12.5.  The low voltage disconnect device is tiny but it's rated at 15 amps, the circuit is cabelled and fused at 15 amps, so it should be safe.

 

Thanks again to all who contributed.

 

[colin]

An update to this thread.

Whilst in the midst of 'The great clear out', I found an old Waaco catalogue and in it I found the device we used with a coolbox.

I believe it was a Mobitronic M-512-PM, and I see several for sale on ebay, if it's the correct item it is fairly sophisticated, there are two levels that can be set, high for starter battery and low for leisure battery, (we always used the high setting iirc).

The device has 3 levels for each setting and these work automatically, when the battery is at full charge the coolbox is fed full power, as the voltage drops the device cuts the power the coolbox can draw to 25% iirc this allows the coolbox to cool at about 50% which we found fine in UK, maybe it would struggle in hotter climes, finally as the device detected that the voltage to be low it cuts power altogether.

We used it with a 'Halfords' coolbox which I believe to have been a rebadged Waaco, not sure if it would work with all coolboxs. I believe some of the more expensive coolboxs may now have this built in.