# 12v TV problem



## 88993 (May 11, 2005)

I have just bought a 12v freeview 7" TV and am having a spot of bother (as always, it seems!).
When plugged into the 12v "vehicle" electrics it works fine but when plugged into the "living" side of the van it mostly won't start. It just keeps clicking every few seconds and gives a glimpse of an image. The voltage is 12.7 or so on both sockets, the only difference is they are powered from different batteries and the leisure battery doesn't seem to be as good as it once was, reading about 12.2 volts after standing idle for a few days.
Any thoughts?
Thankyou!


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## 88993 (May 11, 2005)

Oh yes, it makes no difference if the van is hooked up to the mains, although the voltage reading is higher.


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## Scotjimland (May 23, 2005)

Hi 

You may not have the full voltage at the socket, did you measure it there or at the battery ? or perhaps the socket has a poor/ loose connection.


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## RobinHood (May 19, 2005)

I assume you're running off the cigar lighter or accessory point when on vehicle electrics, and a socket in the caravan part when on Leisure.

Are you measuring the voltage at the battery or at the socket where you're plugging the set in?

It sounds very much like voltage drop in the wiring to the socket. It might be worth seeing whether you can run off the leisure battery directly. (as a proces of elimination).

Some TVs need a decent voltage to run, and if the wiring run to the socket is long and/or thin, it possibly won't get enough voltage.


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## 88993 (May 11, 2005)

Thanks for the quick response.
The voltage is measured at the sockets and I've tried a different plug/lead and a different socket on the leisure side, with the same results.
If it does decide start then it works perfectly.


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## DABurleigh (May 9, 2005)

The next step is to decide whether the problem is with your leisure battery or the wiring from it to the socket. The easiest way of doing this is to try running it direct at the leisure battery, removing it for convenience if necessary.

Dave


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## 93330 (May 1, 2005)

*TV Problem*

Are you absolutely sure the habitation supply POSITIVE is actually positive ?

Regards Terry


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## 93330 (May 1, 2005)

Just another thought, I wonder if you are using an extension lead with a two pin plug top to two cigar lighter sockets ,or two pin plug top to three cigar lighter sockets ? 

I have known these to make a clicking noise when either they have gone faulty or the electrical load has been too much.

Also you need to be very sure that the polarity is correct, if you have a meter best check out the polarity at the cigar lighter output to the TV.

Regards Terry


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## 88993 (May 11, 2005)

Thanks Dave and Terry
The polarity is correct and the tv is connected by a short lead direct to the wired in socket on the van. I will try a connection direct to the leisure battery next as Dave suggested to (hopefully) narrow down where the problem lurks.
Stay tuned- I will keep you informed!


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## Drew (May 30, 2005)

Hi Folks,

Either the wiring to the socket or the television lead is inadequate.

The television is trying to draw more *current *than the cable will allow it to draw. I am almost certain that you will find it is the vehicle wiring.

Cheers

Drew


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## 88993 (May 11, 2005)

Problem solved!
Tried connecting direct to leisure battery with the same result, so it's not the wiring. Tried it again on the engine battery and once again fine, then on the leisure socket one more time and....nothing, not even the little red light this time. It had died on me  So a trip to my local maplin shop (50 mile round trip) I swapped for another TV and bingo! Problem solved. The new one starts each and every time, regardless of where it is plugged in, even when the leisure battery is quite low.

Thankyou all for your advice


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## 93795 (May 1, 2005)

Hi Hymaway, I'm glad you've solved your immediate problem, but from what you've been saying I think you still have a problem on your 12v leisure electrics and you ought to investigate a bit further before it lets you down completely, probably at the most awkward moment. I think there's a law somewhere that governs this happening.


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## DABurleigh (May 9, 2005)

Assuming I have understood correctly the tests that were done, one can clearly conclude two things (AND, not OR):

1) Your leisure battery supplies less voltage under a minor load than your vehicle battery. (No replacement TV is going to correct that).

2) The older TV was more sensitive to lower voltage than the new one.

Dave


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## 88993 (May 11, 2005)

I guess your correct on both counts, Dave. The leisure battery has been showing signs of being less than in top condition, though, as you point out Phil, the wiring to the socket could be inadequate but I'll leave that alone unless the fault occurs again (a case of "if it's not broke...." or "bury your head...."- take your pick!) Which ever, a replacement battery (or 2) will be the first job.
Thanks again for your help and have a great Christmas!


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## DABurleigh (May 9, 2005)

I don't think Phil was pointing to the wiring. Indeed, you had it right when you said:
"Tried connecting direct to leisure battery with the same result, so it's not the wiring."



Dave
Who now also has fault-finding to sort - headphones work but digital speakers don't .......


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## 93795 (May 1, 2005)

Quite right Dave, as you say I was suggesting that there is a problem somewhere. When I bought my van 5 years ago the Leisure Battery never seemed to stay charged for long and I assumed the battery was faulty so I replaced it. After a few weeks the new one appeared to be down a bit so I investigated further and found that the built-in charger was not performing correctly and the only time the Leisure Battery received any decent charge was on a long journey. I replaced the charger and all has been fine ever since.


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## 88993 (May 11, 2005)

Phil
The idea that the charger may not be doing it's job is quite interesting as the battery in question is less than 2 years old and has never knowingly been abused. Any ideas on how to go about testing the charger?


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## 93795 (May 1, 2005)

The way I would check ( possibly not the best or most correct way ) is to monitor the voltage directly on the battery terminals and then switch on the charger. The voltage should fairly soon rise to either 13.8v or 14.4v depending on the type of charger. After say 24 hours the voltage should be steady at 13.8v and stay there. If you then switch off the charger and check the battery voltage about 12 hours later the terminal voltage should be at least 12.6v. If it is lower it is worth charging for another 24 hours, assuming you have already proved that the charger is OK. Then do the same checks again, this should show whether there is a fault with the charger or the battery or indeed something else.


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## 93330 (May 1, 2005)

*In Built Charger*

On a caravan I had a several years ago now, I found the battery was discharging through the charger, around 150 milliamps and was pulling a good battery down after a period of time. The cure was to fit a single pole switch on the positive output side of the charger, isolating it from the rest of the caravan electrics which would still be connected.

The caravan although left for 4 or 5 months without use, found the battery in good condition, around 12.3 volts.

Regards Terry


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## 93795 (May 1, 2005)

Hi Terry, good idea if your circuitry doesn't already allow you to isolate battery and charger, mine does. IMO A battery at 12.3v is not in a very good condition.


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## 93330 (May 1, 2005)

Hi Phil,

It is after 5 months of layup. Had 150mA been drawn for 4 months it would have consumed 432 amps, (if the battery could provide it!) and the voltage would have been zilch.

Most chargers isolate the mains input only, I was trying to demonstrate that a leaky capacitor, diode or capacitor on the output of older uniits, can have an impact on battery life, but without going too technical.

I understand that having no load on the switched mode chargers may not be too healthy.

Regards Terry


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## 93795 (May 1, 2005)

Hi Terry, please read my post again.


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