The kettle debate

QrizB

maxmycardagain said:

how about a 12v kettle boiled of a big car battery charged up by solar panels?

You'll spend more on the battery and panels than you'll ever save on electricity.

A battery like this:

https://batterystore.co.uk/leoch-sfl-85-leisure-battery/

... holds roughly 1kWh of electricity. You'll see its life is rated at 200 cycles at 50% depth of discharge, so you can charge and discharge it with 0.5kWh a total of 200 times before it's potentially knackered. That's 100kWh of cycled electricity for £70, roughly 70p/kWh in battery costs alone.

And if you do that every day, the battery will last for about 200 days - a little over six months.

wild666

Section62 said:

wild666 said:

Section62 said:

Olinda99 said:

Can someone summarise the consensus re kettle boiling for me please?

Only boil what you need.  If that's significantly less than the minimum mark in your kettle then consider using the microwave instead.

(may not be the consensus though)

Many modern kettles have the heating element under a covered base, years ago when the heating element was uncovered this was maybe true but with modern kettles not so IMHO as the heating element is covered by a thin metal layer so one cup could be boiled without any resulting damage to the heating element of the kettle.

Even so, the manufacturer's instructions will often specify a minimum amount of water the kettle needs to be filled with for it to be safely operated.

People should check the instructions for their kettle, rather than relying on the honest/humble opinions of people on the internet.  Those opinions could be wrong, and there is a risk of damage to the kettle, or worse.

My current kettle is 7 years old and I sometimes boil just enough water for one cup with no adverse effects from the kettle like it prematurely cutting out. Now I mainly fill it to about 1.4 litres to fill a flask with a couple of teabags added to the flask but still do occasionally put in only enough for one mug. 

markin

QrizB said:

maxmycardagain said:

how about a 12v kettle boiled of a big car battery charged up by solar panels?

You'll spend more on the battery and panels than you'll ever save on electricity.

A battery like this:

https://batterystore.co.uk/leoch-sfl-85-leisure-battery/

... holds roughly 1kWh of electricity. You'll see its life is rated at 200 cycles at 50% depth of discharge, so you can charge and discharge it with 0.5kWh a total of 200 times before it's potentially knackered. That's 100kWh of cycled electricity for £70, roughly 70p/kWh in battery costs alone.

And if you do that every day, the battery will last for about 200 days - a little over six months.

A 3kw kettle on for only 45sec, 0.113 kw/h or 0.75 kw/h  So it would only sip from the battery? And 2 old car batteries may not have the amps to start a car but they still have a some power.

*Without doing the math... 

Also found when googling.

As a result, when working out how much energy electric kettles use, many people reference electric kettle maximum ratings or simply use Npower’s statement that notes: it takes 3 minutes to boil 1.5 litres of water (i.e. what an average kettle holds), which results in approximately 0.1 kWh of electricity consumed.

https://ecocostsavings.com/electric-kettle-running-costs/

Benny2020

 3kw kettle on for only 45sec is 45/3600×3000=37.5wh?

maxmycardagain

old log stove/fallen wood/whistling kettle then

maxmycardagain

our lounge fire place is blocked off and whilst it has no back boiler, maybe opening it up, and hanging a kettle over it could save winter heating bills and kettle boilings (plenty of fallen trees round here)

back to the medieval way

victor2

markin said:

QrizB said:

maxmycardagain said:

how about a 12v kettle boiled of a big car battery charged up by solar panels?

You'll spend more on the battery and panels than you'll ever save on electricity.

A battery like this:

https://batterystore.co.uk/leoch-sfl-85-leisure-battery/

... holds roughly 1kWh of electricity. You'll see its life is rated at 200 cycles at 50% depth of discharge, so you can charge and discharge it with 0.5kWh a total of 200 times before it's potentially knackered. That's 100kWh of cycled electricity for £70, roughly 70p/kWh in battery costs alone.

And if you do that every day, the battery will last for about 200 days - a little over six months.

A 3kw kettle on for only 45sec, 0.113 kw/h or 0.75 kw/h  So it would only sip from the battery? And 2 old car batteries may not have the amps to start a car but they still have a some power.

*Without doing the math... 

Also found when googling.

As a result, when working out how much energy electric kettles use, many people reference electric kettle maximum ratings or simply use Npower’s statement that notes: it takes 3 minutes to boil 1.5 litres of water (i.e. what an average kettle holds), which results in approximately 0.1 kWh of electricity consumed.

https://ecocostsavings.com/electric-kettle-running-costs/

a 3KW load on a 12V battery would be 250 amps. A bit beyond a brand new car battery, never mind one that can't even turn a starter motor.

Gerry1

markin said:

A 3kw kettle on for only 45sec, 0.113 kw/h or 0.75 kw/h

Apart from the maths being incorrect, the consumption would be kWh, not kw/h.

markin

victor2 said:

markin said:

QrizB said:

maxmycardagain said:

how about a 12v kettle boiled of a big car battery charged up by solar panels?

You'll spend more on the battery and panels than you'll ever save on electricity.

A battery like this:

https://batterystore.co.uk/leoch-sfl-85-leisure-battery/

... holds roughly 1kWh of electricity. You'll see its life is rated at 200 cycles at 50% depth of discharge, so you can charge and discharge it with 0.5kWh a total of 200 times before it's potentially knackered. That's 100kWh of cycled electricity for £70, roughly 70p/kWh in battery costs alone.

And if you do that every day, the battery will last for about 200 days - a little over six months.

A 3kw kettle on for only 45sec, 0.113 kw/h or 0.75 kw/h  So it would only sip from the battery? And 2 old car batteries may not have the amps to start a car but they still have a some power.

*Without doing the math... 

Also found when googling.

As a result, when working out how much energy electric kettles use, many people reference electric kettle maximum ratings or simply use Npower’s statement that notes: it takes 3 minutes to boil 1.5 litres of water (i.e. what an average kettle holds), which results in approximately 0.1 kWh of electricity consumed.

https://ecocostsavings.com/electric-kettle-running-costs/

a 3KW load on a 12V battery would be 250 amps. A bit beyond a brand new car battery, never mind one that can't even turn a starter motor.

I was thinking with an inverter, but with a 12v ..."water can be heated up to the boil in 16 (120W)-20 (80W) minutes."

Spardar Water Heating Cup

https://www.amazon.co.uk/dp/B07M8R8DMW?

https://www.thecarstuff.com/best-12v-travel-car-kettle

There are a few factors to consider when calculating battery runtime including inverter efficiency, voltage, battery capacity, and power draw.

To make it easy I’ve created this formula to use with any 12V battery. Here it is:

(10 x battery capacity in Ah) divided by kettle watts = runtime in hours.

Let’s say you have a 100Ah battery and 1200 watt kettle, it would look like this:

(10 x 100Ah) ÷ 1200W = 0.83 hours. (50 minutes).

So a 100Ah capacity battery will run a 1200W kettle for 50 minutes.

As you can see, a kettle will draw a lot of energy so you need to be careful how often you boil water. Of course, you won’t use a kettle for 50 minutes, more like 5 – 7 minutes at a time. So you’ll likely use 8 or 10Ah of battery energy each time you use your kettle. 

https://wattalot.com/what-size-inverter-to-run-a-kettle

maxmycardagain

GUYs............enough................

lol