1000w vs. 3000w kettle

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GaryMiller

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Our Seaward has been "degassed" and the previous owner has used an electric kettle which is very old and probably not very efficient. I'm going to use a 28kwh lithium battery pack to power a kettle and microwave for the times when the engines aren't running, saving the main batteries for engine starting.
Given that I am a Bear of Little Brain when it comes to things electric I'm wondering what the trade-off would be between a 1000w (less power consumed but longer running time) and a 3000w kettle (quicker but using more power) - any thoughts/experiences gratefully recieved.
Thanks
 
GaryMiller said:
Our Seaward has been "degassed" and the previous owner has used an electric kettle which is very old and probably not very efficient. I'm going to use a 28kwh lithium battery pack to power a kettle and microwave for the times when the engines aren't running, saving the main batteries for engine starting.
Given that I am a Bear of Little Brain when it comes to things electric I'm wondering what the trade-off would be between a 1000w (less power consumed but longer running time) and a 3000w kettle (quicker but using more power) - any thoughts/experiences gratefully recieved.
Thanks
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3000W kettle trough an inverter will draw 300 amps from the battery. Doubt the BMS would support that and would exceed the C rating of the battery.

If on shore power, the 3000W kettle will use most of your 16A shore power supply.

I'd get a 1000 kettle. It's what we use, through an inverter and it works fine, just takes a little longer to boil.
 
westernman said:
How can a kettle be inefficient?
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The longer it takes to boil the more heat it will lose to the surroundings. This is probably offset by the reduced battery capacity under higher load (not sure if this applies to lithium as well as lead acid)
Probably little difference anyway.
 
GaryMiller said:
Our Seaward has been "degassed" and the previous owner has used an electric kettle which is very old and probably not very efficient. I'm going to use a 28kwh lithium battery pack to power a kettle and microwave for the times when the engines aren't running, saving the main batteries for engine starting.
Given that I am a Bear of Little Brain when it comes to things electric I'm wondering what the trade-off would be between a 1000w (less power consumed but longer running time) and a 3000w kettle (quicker but using more power) - any thoughts/experiences gratefully recieved.
Thanks
Click to expand...
I hope you don't mean one of these.delongtop.com/product/28kwh-battery-energy-storage-system-delong/#:~:text=The%20Delong%2028kWh%20lithium%20battery,of%20a%20lead-acid%20battery. It would be helpful to say exactly what battery you are intending to use, how it is charged and how you are converting it to 240v
 
We found a 1000w kettle perfectly adequate for tea and coffee making. Boat hot water is potable and you can save a lot of time and possibly money by using that when filling a kettle.
 
We have a vacuum-insulated electric kettle on the boat. 2.2 kW from memory. It does save some power compared to boiling the same quantity of water in a non-insulated model. It also obviously keeps any water you do not immediately use hotter for longer, although for best efficiency you should only boil just enough water for your drink.

It also has a facility to stop at various temperatures. Some drinks are better with a water temperature less than 100°C, and this further saves power (many non-insulated kettles will also do this). Another feature I like on a boat is a sealed lid (a button press is needed to pour). If it is knocked over, there is no risk of burn.

The only caveat is I suspect it has lost some of its vacuum over the years as it does not keep water hot as well as it did when new.
 
westernman said:
How can a kettle be inefficient?
Click to expand...
That was my thought too…..

Although if you have a kettle that makes a lot of noise I guess there are some Joules not being used for heating. But seeing as you would tend to drink a hot drink when it is colder outside then it doesn’t matter as the sound from the kettle will warm the air in your boat slightly. Bonus!

I always wonder why people get exercised at boiling too much water at home….if you’ve got the heating on at the same time it saves on your boiler running costs.

My pointless post has now concluded.
 
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A 1 kW one for me. If you are ever on shore power you are less likely to trip the incomer. Lower rates of discharge must be better for your battery and who is to 2 minutes anyway!
 
Currently insulated kettles are cheap as chips and available in a variety of shapes, sizes and complexities.

Stop worrying about the kettle and worry instead about your power source, wiring, inverter. Your inverter itself will gobble power, even (or more so) on standby.

Go back to basics and define what kit you have or propose, size of battery bank, size of alternator

and you will get much more useful information.

Jonathan
 
Sea-Fever said:
That was my thought too…..

Although if you have a kettle that makes a lot of noise I guess there are some Joules not being used for heating. But seeing as you would tend to drink a hot drink when it is colder outside then it doesn’t matter as the sound from the kettle will warm the air in your boat slightly. Bonus!

I always wonder why people get exercised at boiling too much water at home….if you’ve got the heating on at the same time it saves on your boiler running costs.

My pointless post has now concluded.
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I sometimes have similar thoughts about ‘wasted’ energy. Unfortunately, my argument breaks down altogether in the summer.
 
I use an 800watt vacuum insulated kettle from either, shore power, 3kVA inverter (5kWh LiFePO4 house battery bank) or 4kVA generator. It's slow but adequate and it allows me to use the microwave (800W) and the water heater (1kW) at the same time. It's amazing how long the vacuum kettle keeps the water hot.
 
PaulRainbow said:
You cannot run a 2.2Kw kettle from a 200Ah Lithium battery, via an inverter.
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2.2 kW was just the size I chose. There are vacuum-insulated kettles of lower wattages available if you are limited by your battery or inverter size. The benefits I mentioned are still applicable.

I suspect it was a typo, but the OP actually indicated he had a 28 kWh battery bank.
 
BTW, I looked up the original testing I did on a vacuum-insulated kettle when it was new. This was in Scotland. Both kettles were set to stop at 90°C (my most common setting). The reduction in power consumed by the insulated model was noticeable. This option is worth considering if you are on a tight energy budget, although keep in mind the durability of the vacuum insulation may be suspect over the longer term given my experience.

The non-insulated kettle required, on average, 114 Wh (this would be about 9.2 Ah for a 12 V system) to raise approximately 1L from around 20°C to just below boiling.

The vaccum insulated kettle required 101 Wh (this would be about (8.1 Ah), but also had a higher finishing temperature (the water was closer to boiling) by around 5°C.
 
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Just how heavy is a 28KWh battery pack? If it really is that capacity no worries about any kettle as long as the inverter can cope.
 
There should be a pressure sealed kettle option. With pressure you could easily exceed 100C and there would be no heat loss from vented steam. It would be much easier to insulate it as well.
 
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