inverters

Hi Peter. I have a 2000w Pure Sine Wave inverter fed by 2 x 110ah batteries which in turn are fed by 135w SP. I have an Avtex television which we use at night or watch a DVD whilst in bed (lovely!) I have to say I have never experienced what you have?? A 12v Avtex is probably the answer ( or any 12v tele- but check the power consumption first!) why run through an inverter when you can run straight off a 12v line.? I only use my inverter when I want to do my toast in the morning (3-4 mins) blend my Keffir or any other dip or sauce, ( 90 seconds), heat something in the microwave (3 mins max) or vacuum (5-6 mins). Don't forget that your inverter is using power whilst on too. The important thing is how many AMPS its using and that will tell you how long you can run a particular appliance but don't forget that only 50% of the battery power is available, so in your case, theoretically- 115amps - as long as your batteries have been wired in correctly. By using Ohms formula, you can determine the amps. My inverter is controlled by an illuminated switch on the end of the bed box so that I can switch it on easily and more importantly, switch it off and kill it when not in use. There is no doubt that non EHU living can be as comfortable as EHU living but things have to be done slightly differently. Hope this helps.

I can think of a couple of tests that will hopefully give pointers to the problem.

Does this TV shut down if run on mains?

Does it shut down if run off the inverter, whilst the inverter is powered by the battery and battery charging? ie when on EHU but left configured to run TV off inverter. Exploring here if the battery is duff.

Some TV have auto shut down after a period, to stop it running on if you fall asleep; is that feature set in its menu?

Using a modified sine wave inverter can distress some TVs the above tests explore if yours is one. If so a pure sine wave inverter will likely cure that. The running directly off mains test gives guidance on that answer.

Most inverters themselves shut down if the battery voltage falls below a set value. The running off the inverter when the battery is being recharged by the EHU should show if that is the issue.

I ran a SONY 15" for years off a quality inverter, no issues at all. Using a modified sine wave inverter it would not run properly; so long ago I can't remember now if it simply would not work or pixilated, but know it was not viable.

Does your TV have an external power supply transformer (black 'brick')?

If so, look on the label and see what the output is.

Most TV's are already 12V DC and for a couple of quid from maplins, you can put a socket and plug in the line out of the transformer and/or use a separate car type adaptor and plug, so you can use it direct into your caravans 12V system or as 240v as you please.

That's what I do with my cheap sub £99 TV/DVD combo unit.

(and you will be able to use it for longer as you are not wasting energy going from 12V to 240V and back to 12v again.) 

Worth a look!

Does your TV have an external power supply transformer (black 'brick')?

If so, look on the label and see what the output is.

Most TV's are already 12V DC and for a couple of quid from maplins, you can put a socket and plug in the line out of the transformer and with a car type adaptor you can use it direct into your caravans 12V system or as 240v as you please.

That's what I do with my cheap sub £99 TV/DVD combo unit.

(and you will be able to use it for longer as you are not wasting energy going from 12V to 240V and back to 12v again.) 

Worth a look!

Thanks everyone for the replies, I had the inverter checked out and it appears that it uses far more power when being used than I expected. I cannot remember the exact readings on the testers device but it was getting towards the same consumption as the appliance that was being used. I have now bought a 12v/240v Avtex 18" tv and will see what happens this weekend whilst wild camping. Cheers, Peter.

How did it go Peter? 

Sorry for the late reply Merve the end result was that one of the two leisure batteries was not quite on the same level as the other so was loosing power on the good one (which was replaced under warranty) I also bought a Avtar 18" tv/dvd which I use on the 12v mode so as not needing an inverter and for the last 3 weekends away on just battery power it has been excellent, as the tv has a battery level indicator function on it you can monitor your usage and power left at any time. The TV's are expensive but well worth the money if you use your van a lot as we do. cheers, Peter. 

That's great news Peter! Thanks for letting us know! It's always satisfying when a plan comes together!!