Right Jan, that's it. Not just a detention, but a letter home to your parents for you.
Actually, this whole amps x volts = watts thing is daft if you think about it. People are quite happy to talk about length not meterage, and mass not kilogrammage, so why on earth not talk about current and not ampage? It's not exactly untrue per se, just a clumsy and unscientific way of putting it.
You were right, though. I accidentally inverted the numbers in the equation. It's been a long day.
Quote: Originally posted by racletcharlie on 17/6/2008
Lots of good information here, so I'll just add the minimum. A difficult task for a Physics teacher, but I'll do my best.
at 250V (ish), 1000W (1kW) will use 2.5 amps. A good rule of thumb. If everything you want adds up to more than 4000W (4kW), you can't use it all at once!
btw speaking as a physics teacher, anyone who writes amps x volts = watts will find themselves in detention. It may be helpful and useable, but it's not correct, dammit.
The correct equation is Current x Potential Difference = Power Consumption
As one who has taught Electronics as part of D&T, I stand corrected on my quoting of Ohms Law. Dumbing down & all that!
This has made it much clearer for me now. We do have a battery charger in the Pullman so that's OK we can charge it overnight when nothing else is being used. Thanks for the tip on not using the 12 amp plugs for bigger things too. I think we have two 12 amp plugs and 2 or 3 240V plugs so two different systems.
Sunfleur
Quote: Originally posted by Steve McV on 17/6/2008
Yes, the battery & EHU are completely seperate. It is not counted in the current drawn from the EHU. The battery will need charging. Some use the EHU with a battery charger in the camper. Some use solar panels or a wind turbine on their camper if there is no hook up. Others charge the leisure battery from the car (via the white plug on their tow bar if you have double sockets). 12V appliances are usually low power as a consequence. You can get kettles, fans & the like, but these will flatten your battery very quickly.
We use the 12V supply for the trailer lights & charging mobile phones, MP3 player, portable DVD etc. Our fridge is a "3 way" that means it will run on gas, 12V or 240V. We run on 12V whilst on the move with the fridge in the car. Mains whilst on site. We don't use the gas as we only use sites with EHU, but that is what it is intended for. The leisure battery would be flat very quickly using the fridge on 12V.
Now then you lot I think my DH will be giving you extra homework!!! He knows - being an Astrophysicist/maths/Physics lecturer - all the amps/watts etc but I just wanted it in real camping speak LOL EG what actual appliances people have had on at one time and information on what happens when you just use your leisure battery! Since I am the one who organises all of the holiday and what we take and use and most of the cooking etc I need actualities - instead all I get from my DH is this times this equals this - that's why I came to you plain speaking lot LOL
So off to bed with no supper for getting your sums wrong LOL
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Topic: How much can you load up on 10 amps
