Bill Wright wrote:
harryagain wrote:


The other good news is that they use electricity all the time.
Whereas a battery operated doorbell only uses power when a finger is
on the button.

So how much does 1kWh cost if you get it from AA cells?

Bill

No-one seems inclined or able to answer this, so I will.

A decent quality alkaline AA battery will produce 2.75 watts for one hour.

1kWh of mains power costs about 10p. So 1 watt/hour of mains costs
0.01p. So 2.75 watt/hours of mains power costs 0.0275p.

If an AA battery of reasonable quality can be had for 10p, that makes
the power from it 363 times the price of mains power.

So so it doesn't matter how you obfuscate it, anyone using batteries
without very good reason is daft.

Having said that, I have a confession. In my house there is a doorbell
sounder powered by four AA cells. It is activated by an external IR
beam. It is not powered from the mains because that would involve me in
5 minutes' work once every 40 years, whereas I seem happier doing the
two minutes' work changing the batteries every verse end.

It was ever thus. The indolence of the so-called working classes is such
a problem to respectable society.

Bill