# tv question.... 2.5Amps on 12v



## lockpicker1969 (Sep 3, 2011)

Hi
I am looking to buy a 12v TV for my van and I have seen many on the market. I have read that these TVs seem to be between 1.5 and 2.5Amps on 12v. It seems that the higher price ones are 1.5 and the cheaper ones are 2.5 what does this mean to the layman and how long could I expect to watch the TV before my 110 Amp battery goes flat? Is there an easy way to work this out? 
Richard


----------



## geraldandannie (Jun 4, 2006)

110 AmpHr / 2.5Amp = 44hr.

In truth, you wouldn't want to run your battery less than 50% charged if you could help it. Serious damage could ensue.

But there is something else which would cut short the time: voltage. As batteries discharge, their terminal voltage drops. At some point, the battery voltage will drop to below that at which the TV will operate, and it will shut off. But the ability of the battery to sustain a reasonable voltage over discharge will depend on its age and quality.

There's a great guide on batteries written by Safariboy:

http://www.motorhomefacts.com/ftoptitle-65111-use-and-care-of-batteries.html

Read it, and you will be enlightened :wink:

Sallytrafic has also written a guide, which could be useful:

http://www.motorhomefacts.com/ftoptitle-67769-amperage-questions.html

Gerald


----------



## rosalan (Aug 24, 2009)

My battery goes below an acceptable level of charge and the tv goes off, when 'Coronation Street' comes on. :lol: :lol: 



Sorry to be facetious but I am having that sort of day.


----------



## weldted (May 1, 2005)

*tv use*

a rule of thumb, a fully charged battery in good condition will give approx half its rated capacity so 110 = 55, 85 = 42 etc before discharge becomes low enough to effect the batteries ability to recover. The more often a battery is deeply discharge the short the battery will last.


----------



## lockpicker1969 (Sep 3, 2011)

Correct me if i am on the wrong track but would my calculation go something like
2.5Amp (tv) divide by 55 (half rated battery) = 22hrs possible view time of coronation   st ?


----------



## hampsterracing (Jun 2, 2011)

lockpicker1969 said:


> Correct me if i am on the wrong track but would my calculation go something like
> 2.5Amp (tv) divide by 55 (half rated battery) = 22hrs possible view time of coronation   st ?


Yep 

thats with an as new fully charged battery and no other load (lights,waterpump etc) but plenty for an evening


----------



## vardy (Sep 1, 2006)

I'm runnin my little Maplins telly off the Halfords brick - I get about 10hrs.


----------

