When you get to be an old fart like me , you tend to have a lot of time to think about what not to do today. This is one of thoes days, but the mind was wandering. It came to me a solution to a battery problem , how do i keep it charged ?. If i put my inverter on, and plug a battery charger in to it ,then clip it on to the van battery, the power used by the inverter is less than the charge going into the battery, bingo perpetual power !!!!!!!. Ok i know , if its not been done already , Why ???. Come on boffins , over to you.
inverters
- Thread starter GrahamDerby
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The inverter might use less power but how about the power the charger draws?
Surely you want the battery powering other things as well and they will draw off power from the battery, so what eactly is the point of a battery inverter charger loop
Surely you want the battery powering other things as well and they will draw off power from the battery, so what eactly is the point of a battery inverter charger loop
Hi, if you think that is going to work, then I have this perpetual motion machine you might be interested in.
Many years ago when Adam was a lad and King Kong was a monkey and Brum was doing his GSE physics at school, we looked at a similar set up.
It was about an electric motor powering a generator, that generator in turn powered the electric motor
Teacher simply said that God was a Yorkshireman, the moral was "Thou dunt get owt for nowt"
It was about an electric motor powering a generator, that generator in turn powered the electric motor
Teacher simply said that God was a Yorkshireman, the moral was "Thou dunt get owt for nowt"
Agreed, but I use an inverter in the car to power the charger for my wife's mobility scooter, thereby getting 24v, via 240v, from 12v.
And as I'm using the car anyway, I'm virtually getting that power for free!
And as I'm using the car anyway, I'm virtually getting that power for free!
Virtually, yes, actually, no. The extra load on the alternator to produce the charge for the scooter battery means that the engine has to work a bit harder, which leads to a small reduction in miles per gallon. How much, of course depends on how high the charge rate is.
And for anyone who has not yet tried this experiment.... with a warm engine and somewhere private to park (you'll see why in a minute), handbrake on, let the engine tick over in neutral, note tacho speed (or listen to the engine speed) Then without touching the accelerator, turn on as many high amperage items at once...heated rear sceen, washers, wipers, headlights, radio, rear fogs, brakes, electric steering (turn wheel) so you are pulling an extra 30+ amps from your alternator. The engine will slow quite noticeably as a result, proving that you get nothing for nothing. (Then turn everything off again, or people will think you're odd!) I forget the precise technology, but the field magnets increase their power in order to get more amps out, and this causes a real drag on the alternator turning....or something similar. Driving with no lights on is more economical - but not as safe!
I have a 1948 Auto Electrics Manual which does not even hint at dynamos which can produce that sort of current!! In those days there were fewer electrical devices (heater, what's that? ditto radio, etc), and if your dynamo couldn't cope with all your lights on at once, you just had to turn some off! or flatten your battery.
I have a 1948 Auto Electrics Manual which does not even hint at dynamos which can produce that sort of current!! In those days there were fewer electrical devices (heater, what's that? ditto radio, etc), and if your dynamo couldn't cope with all your lights on at once, you just had to turn some off! or flatten your battery.
- Mar 14, 2005
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The reason is that none of the components are perfect. They all use more power than they convert. The difference comes out as heat, sound and light.
The very best inverters are only about 90% efficient,
The very best battery chargers are only about 90% efficient
lead-acid batteries are only about 50% efficient at storing electrical charge.
Wires have some resistance which means any current passing through them will generate some heat.
The very best inverters are only about 90% efficient,
The very best battery chargers are only about 90% efficient
lead-acid batteries are only about 50% efficient at storing electrical charge.
Wires have some resistance which means any current passing through them will generate some heat.
Pedantic maybe, but a battery produces electricity by a reversable chemical reaction. The electricity is not "stored". However, a capacitor does store electricity.
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