help needed????

[troy]

hi all i have just purchased a 150w invertor and would like to know roughly how long i would be able to run a 240v tv/dvd combi...... the lesure battery is 90w and thinking of getting another 90w battery to connect together.... or would i be better off getting a 12v tv/dvd and any idear how long i would roughly last on both.... i just new to all this. so i would appriciate any advise would be great many thanks troy

[colin]

The one answer i can give you is that a 12v tv should last longer than 240v as you are doing away with the inverter and transformer and the loss' involved with them. As for the rest of your question, you will need to work out the current draw for inverter (they vary dedending on type ) and the power requirement for tv, 150w will be strugling. Apologees to Mel B? i only have 'o' level english so can't spell

[Clive]

I think you mean that the Leisure batteries are 90 ampere hours rated capacity. If we assume 80% charge then thats an effective 72 ampere hours. But as its not good for battery life to discharge below 20% then you should work on a figure of 54 ampere hours from a 90 ampere hour rated battery treating it gently. A typical TV DVD Combi (like the new one in our bedroom) is rated at 74 watts. (From the book, more than I expected!) if this were 12 volts it would be a tad over 6 amps (74/12). But through an inverter at say 90% efficiency the current taken would be a tad under 8 amps. But this is a MAXIMUM power consumed by the combo, maximum brightness, full volume etc. At this rate the 54 ampere hours would be used up in about 7 hours of viewing. If you have two leisure batteries then 14 hours of viewing. BUT have you read the handbook for your TV/DVD combo to find out the watts? And more accurately just connect it to the inverter and measure the inverter input current with an ammeter to find the real figures. Good luck Clive