Slow cooker amp hour draw

[canalrunna]

Can someone tell me how many amps a 240v - 200w slow cooker will take out of the batteries over a 7 hour period when not on a shoreline please

[Tony Brooks]

5 minutes ago, canalrunna said:

Can someone tell me how many amps a 240v - 200w slow cooker will take out of the batteries over a 7 hour period when not on a shoreline please

Well it won't be amps, it will be amp hours, so ignoring the fact its probably thermostatically controlled 200w at 12V = about 20 amps allowing for a 80% inverter efficiency so over 7 hours that is 140Ah. I very much doubt it will be anything as high as that but on your data that is all that can be said.

 

It as often been said that anyone who uses batteries to supply the power to produce heat is a battery destroying clot.

 

If you cruise for that 7 hours then the battery discharge from the slow cooker will be pretty much close to zero because the alternator will supply it.

Edited May 10, 2020 by Tony Brooks

[canalrunna]

Thanks Tony

 

[waterdog]

Our Morphy Richards one is labelled at 130 to 163 watt. 

Works great when on days cruise (remember when we could do that) just bung it it on in the morning and you have a hot meal ready when you stop.

 

Even now while in lockdown the solar usually keeps up with it without the need to run the engine. ( Not today though, no sun )

[nicknorman]

49 minutes ago, Tony Brooks said:

Well it won't be amps, it will be amp hours, so ignoring the fact its probably thermostatically controlled 200w at 12V = about 20 amps allowing for a 80% inverter efficiency so over 7 hours that is 140Ah. I very much doubt it will be anything as high as that but on your data that is all that can be said.

 

It as often been said that anyone who uses batteries to supply the power to produce heat is a battery destroying clot.

 

If you cruise for that 7 hours then the battery discharge from the slow cooker will be pretty much close to zero because the alternator will supply it.

Do slow cookers have some sort of thermostat? Just wondering if it will take the 200w whilst heating up (for a few hours, probably) then use less as the thermostat kicks in and out.

[waterdog]

7 minutes ago, nicknorman said:

Do slow cookers have some sort of thermostat? Just wondering if it will take the 200w whilst heating up (for a few hours, probably) then use less as the thermostat kicks in and out.

Ours has a stat, once up to temp it cycles on and off as required.

[ditchcrawler]

27 minutes ago, nicknorman said:

Do slow cookers have some sort of thermostat? Just wondering if it will take the 200w whilst heating up (for a few hours, probably) then use less as the thermostat kicks in and out.

Ours dosen't, just a 3 heat switch high low and warm

[Richard10002]

21 minutes ago, ditchcrawler said:

Ours dosen't, just a 3 heat switch high low and warm

Isn't that a stat without numbers?

 

One could guess that low will not use much power, medium perhaps half power, and high full power? If the user manual gives the various wattages, the useage in Ahs could be more precise. e.g. if low uses 50w, that would be about 5A, so 35Ah in 7 hours.

[mrsmelly]

Cos I am messing today I have just checked slow cooker for the OP. When on high mine draws 16 amps, when on low setting it draws 10 amps. When on auto it starts on high 16 amps but is on a thermostat. So when it gets up to heat it obs cuts in and out and that is going to depend on how long the peace of string is such as how much stuff is in the cooker? what is ambient temperature etc etc. So worst case scenario it uses 16 amps and whatever that equates to.

[ditchcrawler]

2 hours ago, Richard10002 said:

Isn't that a stat without numbers?

 

One could guess that low will not use much power, medium perhaps half power, and high full power? If the user manual gives the various wattages, the useage in Ahs could be more precise. e.g. if low uses 50w, that would be about 5A, so 35Ah in 7 hours.

No its three different powers, there is no stat on ether of ours. I have measured the current drawn from the batteries at different settings but can't remember them

 

Edited May 10, 2020 by ditchcrawler

[canalrunna]

Thanks all for your answers, looks like we should cope with using it.

[cuthound]

14 hours ago, canalrunna said:

Thanks all for your answers, looks like we should cope with using it provided the engine is running.

 

Amended that for you. ??

[mrsmelly]

Just now, cuthound said:

 

Amended that for you. ??

I tend to agree. If its drawing 16 amps for 6 hours ( slow cooking ) its a fair amount and has to be put back somehow. As others have said though if doing a days cruising they make sense and indee on leccy hook up innitt.

[cuthound]

26 minutes ago, mrsmelly said:

I tend to agree. If its drawing 16 amps for 6 hours ( slow cooking ) its a fair amount and has to be put back somehow. As others have said though if doing a days cruising they make sense and indee on leccy hook up innitt.

 

I know we use ours to ensure we have a piping hot stew or chilli con carne at the end of a cold winters days cruising.

[ditchcrawler]

With ours we cook while travelling and then MAYBE it will sit for an hour or so on the LOW setting. As I said I have measured the current but cant remember it, I think low was about 4 amps on 24 volts including the inverter.

[Onewheeler]

I built a well-insulated box (50+ mm polystyrene foam) recently for making black garlic. It takes 15 W on average to maintain 65 C (trace heating tape with a thermostat). It would easily hold a pan of stew for two. Put it in hot and I reckon it would only need a handful of AH to keep warm all day.

[ditchcrawler]

1 minute ago, Onewheeler said:

I built a well-insulated box (50+ mm polystyrene foam) recently for making black garlic. It takes 15 W on average to maintain 65 C (trace heating tape with a thermostat). It would easily hold a pan of stew for two. Put it in hot and I reckon it would only need a handful of AH to keep warm all day.

Slow cookers get nearly as hot on the outside as they do on the inside. Insulation as you say is the answer

[Guest]

Have a look at this from Foxes Afloat:

https://youtu.be/_8Yn-UvzmEQ

A "thermal cooker" - current draw 0A.

Didn't ever think I'd contribute to a cookery thread, but there we are.

[Nightwatch]

36 minutes ago, Martin Nicholas said:

Have a look at this from Foxes Afloat:

https://youtu.be/_8Yn-UvzmEQ

A "thermal cooker" - current draw 0A.

Didn't ever think I'd contribute to a cookery thread, but there we are.

I watched that. They look impressive them there Thermal thingies.

[ditchcrawler]

40 minutes ago, Nightwatch said:

I watched that. They look impressive them there Thermal thingies.

hay ovens

[STRONGHOLD]

I'd use one of two options instead of using the batteries: a pressure cooker on the hob, or a cast iron lidded casserole perched on the multifuel stove, if you have one.  Either way, you're going to have a great tea.

[Baralacha]

I'd agree with the previous poster about avoiding such  a drain on batteries.

 

If you can afford it, the Wonderbag seems to be well received (not tried it personally, but the ladies on The Narrowboat Experience did and liked it), and buying one helps people in developing countries save fuel with their cooking

https://www.amazon.co.uk/Wonderbag-Portable-Cooker-Recipe-Khaki/dp/B00FXKMJI8

[blackrose]

I'd only use my slow cooker either via the inverter if travelling or from shore power, then they are great devices. Chuck a load of stuff in and set off for a day's cruising. After a few hours the smell of the stew or curry or whatever you're cooking starts wafting out of the boat and a few hours later when you moor up cold and tired dinner is ready with no battery drain at all.

[ditchcrawler]

1 hour ago, blackrose said:

I'd only use my slow cooker either via the inverter if travelling or from shore power, then they are great devices. Chuck a load of stuff in and set off for a day's cruising. After a few hours the smell of the stew or curry or whatever you're cooking starts wafting out of the boat and a few hours later when you moor up cold and tired dinner is ready with no battery drain at all.

That is how we use ours. Terribly inefficient things pumping out as much heat as they use to cook. I looked for a cool touch one with no luck

[ChrisRichmond94]

I love my slow cooker.