Votage drop....???

[SKT]

So after bragging about the ABR Sidewinder fridge and battery box I bought it starts to go to sh1t.....

I've noticed that of late the Isolator built in to the batt box has been chattering. I read in the instructions for the box this usually means that the alternator voltage is dropping below 14v. The anderson plug at the back of the car is actually wired via a incar Redarc dual charge isolator so I'm going to wire round it and see if it stops that.

In hand with that.... the fridge should give an initial 'beep' and then display the current temp then after a few minutes the main fridge fan kicks in and its starts to cool.
At the moment the fridge does all except the fan does not come on and the fridge never cools..... not really any good at all. I've run the fridge using the 240v power supply that comes with it and it runs fine.
I have tested the fridge off the battery box and straight off the in-car 12v cigy sockets. Same results. I e-mailed the maker of the box and fridge and he said if it runs fine on 240v then its fine..... its not getting the required 12v on start up....


I'm no jet with power.... I dont see how it can get some power but not enough tot do the job..... any clues...????

Scott

 

[nipper]

I hate inverters. Altenator output can vary between 12.5 volts to 14.3 volts and be normal. The lower end is everything on and at a stop light. The higher end is everything off and cruising down the highway.

I have ditched big inverters in favor of smaller more task oriented ones. I had a 1200 watt inverter that never worked for the reason you cited, and on top of it the freaking thing had an alarm on it to tell you the voltage was too low (but was in actuality fine).

Check the connector and power at the socket. I am not happy with the mfg's response.

nipper

 

[SKT]

I hate inverters. Altenator output can vary between 12.5 volts to 14.3 volts and be normal. The lower end is everything on and at a stop light. The higher end is everything off and cruising down the highway.

I have ditched big inverters in favor of smaller more task oriented ones. I had a 1200 watt inverter that never worked for the reason you cited, and on top of it the freaking thing had an alarm on it to tell you the voltage was too low (but was in actuality fine).

Check the connector and power at the socket. I am not happy with the mfg's response.

nipper

Just to clear it up..... Its not an inverter.....???

Its the isolator/charge unit. The fridge has just one input but must have a built in inverter to deal with it all.

Gonna pop the back of the fridge today and probe around.... if it goes wrong tell my wife I love her :iconwink:

 

[eden]

is the 240V power supply an inverter/power pack or a plug straight in job? i wouldn't pull it apart without some more testing as it might void the warrenty

 

[Kevin]

I dont see how it can get some power but not enough tot do the job..... any clues...????

Scott

My fridge needs a certain voltage (a little less than 12V) to start. This is to protect the battery and also to protect the fridge as it seems that running with low voltage is bad for fridge. I investigated it once as I wanted it to keep running at a lower voltage as I use a 2nd battery - but its circuitry won't allow it.

 

[Kevin]

The fridge has just one input but must have a built in inverter to deal with it all.

The "transformer" (240V to 12V) may be in the 240V power supply - is it like a laptop power supply? This would be why the manufacturer can claim your car is not delivering the correct voltage knowing that the 240V power supply is delivering a full 12V.

 

[SKT]

is the 240V power supply an inverter/power pack or a plug straight in job? i wouldn't pull it apart without some more testing as it might void the warrenty

The manufacturer suggested I test it myself.... him being in Brissy and me being in Perth.

The "transformer" (240V to 12V) may be in the 240V power supply - is it like a laptop power supply? This would be why the manufacturer can claim your car is not delivering the correct voltage knowing that the 240V power supply is delivering a full 12V.

The 240v power supply has the following written on it....
Input 120-240vVAC
Output 13.5VDC 10Amp

Today I plugged the fridge straight into a mates 12v cigy plug of his car and the fridge cranked up fine.
Complete with 'beep'.... temp display.... then within 60 secs the compressor and fan kicked in and it started to cool.

So..... it seems that the voltage coming from the car batt and the batt in the batt box is not enough to get the fridge into complete operation.... thus the manufacturer was able to say that the fridge was fine due to the 240AC-13.5DC power supply.

Giving me the sh1ts somethin royal now....

 

[SKT]

OK.... positive results.....

When I did the powerplant transplant 12 months ago I had a dual batt Redarc isolator installed.... it runs to the anderson plug up rear.

For a while now, as I said before, the isolator in the sidewinder batt box has been chattering. I decided to slightly re-wire the box, around the built in isolator now relying totally on the in-car isolator.
Firstly.... when I plugged the fridge in after wiring round the batt box isolator, the fridge came to life without any issues and started cooling without issues.

Sweet :biggrin:

It seems that the batt box isolator is somehow restricting the voltage to the fridge. And with it out of the picture the battery in the batt box is now charging from the car via the in-car isolator and charging sweet.... and obviously there is no bloody anoying chattering.....

Seems to be all good for now.

 

[SKT]

NOT HAPPY JAN.......!!!

Bad news regarding the fridge....

Now it wont even start the compressor or fan off 240v...

I have had so many mixed results from this fridge during my testing over the last few days....

I have had it arc up on 240v.
I have had it arc up on 12v from my car, my batt box and 12v from my mates car....

I have walked away and 20 minutes later it wont arc up off any source whether it be 240v, 12v off the car or 12v off the batt box.

Always gets the 'beep' and displays temp but no compressor or fan..

 

[SKT]

May have been a low batt....

Still a few unexplained things.... we'll see.

 

[Kevin]

I imagine having 2 isolators / battery controllers in the circuit is not a good thing. One unit may confuse the other - hence the "chattering" which at a guess is the isolator trying to determine when to drag power away from the main battery.

Could you have now blown a fuse in the fridge by chance?

 

[SKT]

I did say before I am not a jet with power.....

I charged the batt a bit and it seems the fridge is working fine. The box has a LED meter and based on previous use I was happy there was enough charge for the job.

I remember the fridge used to arc up in what seemed like just a few minutes.
The manufacturer said it should take 6-9 minutes.
So after more testing and a charged batt it seems the fridge is working fine.

I reckon the issue here is my impatience and a failure to run with a charged batt. I did have the fridge out camping on friday and it did fail to cool. I believe that was due to a flat batt.

The manufaucturer said the chattering in the batt box is usually a sign of a flat batt and can be a sign of a failed cell within the battery. I'll keep an eye on it and make sure its charged whenever I want to use it from now on.

I am sure that something somewhere is not performing like it used to but nothing is perfect I guess. Thx for all you assistance.

 

[Eastie]

I have an inherent dislike for “bling” in circuits that is installed for supposedly useful purposes (but ultimately does little to understand the condition and time left in batteries). Typically it just adds more connections, more resistance, more heat and voltage drop, so that’s where’d start looking also.
It sounds like you’re working it through in a pretty logical fashion, so given the fridge is working some next steps you might want to look at are voltage drop and a bit further assessment of the wiring size and circuit connections.
From my experiences a lot of fridges can be finicky in not starting up straight away once they have been flicked off or cut-out due to low voltage – as you’ve experienced they do eventually rest and go again if they are getting enough volts and amps. I’m not sure why this is, but keep it in mind.
I’m wondering if the circuit’s got enough capacity for the juice the fridge needs, which is likely >12.4v and somewhere between 5-10 amps (probably at the higher end of this, and possibly even a higher spike upon startup) for the compressor to even think about firing up. A lot of fridges are spec'd to only cope with a 3% voltage drop = 0.37 volts.... not very much at all. I’ve never heard of a problem with a redarc isolator, so I suggest you leave that in place for now and bypass the jewellery in the battery box - if that doesnt work then diconnect the redarc and re-connect the battery box to see if it works. Hopefully it's just a case of a dead deep cycle due to excessive discharge. Here’s some other questions and areas to eliminate:

• What size cable did you run from the battery to the redarc, from the redarc to Anderson plug and negative from the Anderson plug to earth? (hopefully no smaller than 8 B&S / 7.91mm2 copper conductor)
• What sort of terminals have you used for the wiring? Did you crimp them or solder them?
• Where did you earth the redarc? (did you earth it to an earth point or scratch paint off to ensure a good earth?)
• Where is the Anderson plug earthed? (again, did you earth it to a chasis earth point or grind the paintwork off, not just put it under a bolt?)
• Have you got a fuse/breaker in the cable to the second battery, if so is it auto re-setting? What sort of connection is it, crimped/soldered?
• You are using the Anderson plug to connect the second battery right, not a cig plug?
• Are you using a hella plug/socket for the fridge, or a normal cig lighter socket/plug? (normal ones can have problems with making a good connection)
• You said it's possible that you’ve over-drained the deep cycle - how bad? to a point where it’s failed or not fully charging or holding charge?
• How new/good is the car’s primary battery – is the red light on the redarc coming on within a minute of the car starting?
• Have you got a smart battery charger (ctek or the like?) to keep your batteries fully charged?
• Do you have a multi meter? If so, have you tested voltage drop in the circuits?

If you need help with testing voltage drop, follow this as it’s fairly simple with a multimeter: Turn the car engine and fridge on and make sure you have access to the power terminals of the fridge, either as they come of your second battery or more ideally at the fridge itself (which may mean opening it up). With the multimeter set to volts DC, connect the positive (red) test lead to the primary car battery positive (+) terminal, and the negative (black) test lead to the + terminal of the fridge (or fridge lead), this will give you a direct reading of the + voltage drop, make a note of it. Now connect the positive (red) test lead to the ground terminal of the fridge/fridge cord, and the negative test lead to the negative (-) terminal of the primary car battery. Your multimeter will again give a direct reading of the voltage drop, make a note of it. Add the two voltage drop figures obtained, and this is the total circuit voltage drop. If you are losing more than 1 volt (e.g. >7% given 12.4-13 volts) this may affect the fridge starting up, especially if the alternator is not giving 100% performance.
Another way to spec voltage drop in a design before install is = length of conducttor (m) x current (amps) x 0.017 divided by the cross section mm square of the conductor (sq mm of copper, not the plastic).

If you can get to a point where you know it's not the wiring or the batteries then check out the alternator. If this all comes up fine you know it's almost certainly the fridge and you will have some evidence to go back to ABR with to see what they recon.

As a work around you could attach the fridge directly to the andersons plug (make a short connection lead) and see if the problem goes away.

 

[SKT]

I have an inherent dislike for “bling” in circuits.....

This reply should be a sticky......

Thx heaps mate. Plenty of info and at the right level most mugs can use.
I didnt install the redarc or the anderson plug myself but it is a very hvy looking cable... easily above the size you stated necesary.

The next point that rabs me is the lack of charger. I pretty much just let the batt sit there and every couple of months I put it in the car for a few days leading up till when I want to use it. Its worked previously but I thihk I am going about it all wrong....

By having it on a charger is it going to effect my power bills....??? regardless is that going to eliminate all batt probs as in will it always be good to go....???

I am using a hella plug off the bat box.

I have the anderson plug cabled to the redarc which is then cabled to the main battery. And the batt box plugs into the anderson plug and the fridge into the batt box via hella.
Question.... the redarc is a small unit, I believe its a SmartStart, as I said I didn't install it but I looked at the Redarc site and saw what I believe to be my installed unit.... Its fairly tucked away under the main batt so I cant see a LED anywhere. I hadn't looked but hadn't noticed one when testing.

I have wired around the isolator inside the batt box so only the in-car isolator is doing the job now.

I think the main issue is that I am not keeping the batt in good condition and then expecting it to just arc up the fridge with no issues after sitting dormant for 3-4 months. Pretty bad move I'd say.... I should know better really.

 

[SKT]

OK....... so I've found the LED on top of the Redarc.

Its on pretty much whenever the car is running.

After reading some online instructions I can say that if that light is on the main battery is above 12.5v and its happy to charge the auxillary batt.

Seems to be ok I guess.....

I prob do need to get a charger to keep the batt in good health.
What am I looking for in charger for this purpose...??? or any other use aswell I guess.
What sort of price should I be paying....???

 

[Eastie]

No prob mate - I'm no expert in elec but I've had enough problems and rested an elbow on enough wheel arches while our auto elec has problem solved and fixed stuff that I've picked up a few things here and there. I hope it helps sort out your problems. It sounds like the main battery is holding it's voltage if the redarc is opening fairly quickly and the wiring is of decent size. All I can add is get a charger and use it - deep cycles are easily damaged by over-discharge. Get a good charger and see if you can restore it to full capacity. Also use it on your main battery once a month.

I recon opinions on chargers is almost as wide and varied as that on driving lights. Some say smart chargers are an overkill on lead acid/gel cell batteries, others swear by them. All I can say that after years of using a simple float charger from repco I switched to a ctek 7amp as that's what a good mate, an auto elec and diesel mech, recommended I use for the batteries we use on our equipment. Over the past 2 years of use, about once a month on each machine, we've had a noticeable reduction in battery replacement and jump starting (so our auto elec hasn't benefited from his recomendation). I also use it on my deep cycle dual battery and haven't had an issue of running out of power for the fridge and lighting on weekends. As a guide I got the ctek 7amp at cost price of $180, and they seem to retail for around $210-$250 (have a look at ebay for an idea). Expensive for a single vehicle so you may want to check out othere options also and weigh up the bang you can get for the $'s you have.

For further explanation on chargers (and fridges, etc) have a look at this site: https://www.fridge-and-solar.net/smart.htm