Leisure battery clip on Inverter

[lakeside]

I recently bought an Odoga 300W inverter principally on the occasion I need to charge my laptop. In the car I do have three cigarette light sockets, one on the leisure battery, and a cigarette lighter extension cable. Odoga recommend to charge a device larger than 200W I could get a clip on and cigarette lighter adaptor linked direct to the car, or leisure battery. I then could add the inverter and the appliance. I have a leisure battery. I do hope I have explained that enough. I am not electrical savvy and wonder if someone has advice on this set up or even used one.
I do hike multiday walks and sleep in my van, and would like a set up that would boil a kettle quickly.
I do have a small camping gas stove and did on one trip have a mild panic when my carbon monoxide alarm went off; 99% sure it was the low battery alert. I would therefore like to use electricity as much as possible.

[Sol]

Ok, I'm an electrical engineer so can help directly on the power question, the average kettle is 2000W and a fast boil one is nearer 3000W (3kW) - so you would need a minimum of a 2000W inverter to power it, and as a rule of thumb you should have a bit of spare otherwise the inverter is running flat out.

So for some calculations - without taking losses into account:

2000W / 230V = 8.7A on the mains side. Watts is Watts when it comes to inverters (losses add extra to the pot too but we're ignoring them for now.)

So from your battery you also need to pull 2000W:

2000W / 12V = 166A so to boil a kettle (3 mins) you need 166A for 3 mins from the battery.

A 100Ah battery can supply 100A for 1 hour, or 200A for 30 mins, 400A for 15 mins etc (divide battery Ah rating by the fraction of an hour in minutes, so to find the fraction of an hour in minutes, you divide the number of minutes by 60 (15/60 - 0.25) then divide the battery Ah rating by the result)

100/0.25 = 400 (just an example) so at a steady 166A draw, the battery would last 100/166 (h) = 0.6 h or 36 mins from fully charged.

The only issue would be finding a 2000W inverter. A 100Ah leisure battery would be fine.

[cliffy]

Caravan shops sell lower wattage mains kettles (usually about 1000W) for about £30, which might be enough for your needs and would mean you could use a lower power inverter. Quest is the make of my caravan kettle.

[lakeside]

I do have a 120W travel kettle but it seems to take an age to boil. I also have a 900W travel kettle which we used to take on skiing holidays as the apartment we used in only had a coffee maker; probably ought to try that one in the Berlingo.

[Matt Haigh]

This seems like a lot of investment to replace (just one part of) what a gas stove can do. I recognise you've had a bad experience with this set up in the past but there are 1000's of boats, caravans that do this quite safely.

[cancunia]

This seems like a lot of investment to replace (just one part of) what a gas stove can do. I recognise you've had a bad experience with this set up in the past but there are 1000's of boats, caravans that do this quite safely.

I'm a bit paranoid about gas stoves in such a small space so I always use my stove with the tailgate open. I can see how that might be a problem early morning or when it's raining. I've yet to see a 12v travel kettle or cup water heater that works quickly since most are designed to work on fairly low wattages, same thing goes for inverters. 
I'd be interested to know if there's a device out there that works in a reasonable time though.

[Sol]

This is a good calculator for boiling water, change it to C and Litres :

https://bloglocation.com/art/water-heati...ergy-power

To boil 1 Litre of water in 3 mins, from 10 Deg C takes 2.07Kw.

[lakeside]

"This seems like a lot of investment to replace (just one part of) what a gas stove can do. I recognise you've had a bad experience with this set up in the past but there are 1000's of boats, caravans that do this quite safely."

You are right; I will be using my gas stove; sometimes in the morning- getting dressed, pottering about, similar in evening after hiking, I do put on the small electric kettle for a bit of a head start.

[GraemeT]

Hi - on the gas stove/carbon monoxide topic...
We have something similar to this:

https://i1.adis.ws/i/washford/291036?w=7...t=webp&v=1

i.e. cheap Chinese single burner that takes small cartridges. Recently we had a scheduled power cut so grabbed the gas stove to boil up a pot of water for cooking. That kicked off the CO alarm that is in the front room next to a log burner (i.e. about 12 feet away from the kitchen and through two (open) doors).

Reading was 400 parts per million but who cares as we didn't hang about long enough to worry. Sure it was a low battery in yours? I'll not be using ours again inside a house, tent or caravan any time soon.

[lakeside]

Greame T, I lost faith in that carbon monoxide alarm so have a new one. Now last thing at night I put my gas bottles outside the car.