Slow cooker amp hour draw

[Tony1]

On 10/05/2020 at 13:50, Tony Brooks said:

 

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

 

 

Obviously not wanting to be picky or anything, but from what I've seen a small 700 watt (or even 1000 watt) kettle seems to work ok, at least with lithium batteries. 

In fact, since I stopped using the gas to boil water for hot drinks, I only need a new gas bottle every 6 months, where it used to be 2 or 3 months. 

 

I do worry a bit about using my batteries to heat the immersion, as its more than 80 amps draw for about 40 mins, and I do think it will reduce the lifespan of the batteries, but so far they seem roughly the same as they were almost 2 years ago when I got them. But I'll know more about the effects of that in the longer term. 

Last year I got solar hot water (via the batteries and inverter) for at least half of the year. It seems such a shame not to use all that solar power to heat the water.

I've tried to find an electrician to fit a device that will reduce the current draw to the immersion down to 40 amps, as I think that will put less stress on the batteries, but for many of them, its as if I've asked them to install a small nuclear power station on the boat. 

 

Edited January 31, 2023 by Tony1

[Tony Brooks]

1 minute ago, Tony1 said:

 

Obviously not wanting to be picky or anything, but from what I've seen a small 700 watt (or even 1000 watt) kettle seems to work ok, at least with lithium batteries. 

In fact, since I stopped using the gas to boil water for hot drinks, I only need a new gas bottle every 6 months, where it used to be 2 or 3 months. 

 

I do worry a bit about using my batteries to heat the immersion, as its more than 80 amps draw for about 40 mins, and I do think it will reduce the lifespan of the batteries, but so far they seem roughly the same as they were almost 2 years ago when I got them. But I'll know more about the effects of that in the longer term. 

Last year I got solar hot water (via the batteries and inverter) for at least half of the year. It seems such a shame not to use all that solar power to heat the water.

I've tried to find an electrician to fit a device that will reduce the current draw to the immersion down to 40 amps, as I think that will put less stress on the batteries, but for many of them, its as if I've asked them to install a small nuclear power station on the boat. 

 

 

Yes, lithiums change the game, as long as you can recharge them. It is far easier with lithiums, but if one is relying on solar in winter on a series of very dull days you may run into problems, but at least you won't sulphate the bank.

[rusty69]

15 minutes ago, Tony1 said:

 

Obviously not wanting to be picky or anything, but from what I've seen a small 700 watt (or even 1000 watt) kettle seems to work ok, at least with lithium batteries. 

In fact, since I stopped using the gas to boil water for hot drinks, I only need a new gas bottle every 6 months, where it used to be 2 or 3 months. 

 

I do worry a bit about using my batteries to heat the immersion, as its more than 80 amps draw for about 40 mins, and I do think it will reduce the lifespan of the batteries, but so far they seem roughly the same as they were almost 2 years ago when I got them. But I'll know more about the effects of that in the longer term. 

Last year I got solar hot water (via the batteries and inverter) for at least half of the year. It seems such a shame not to use all that solar power to heat the water.

I've tried to find an electrician to fit a device that will reduce the current draw to the immersion down to 40 amps, as I think that will put less stress on the batteries, but for many of them, its as if I've asked them to install a small nuclear power station on the boat. 

 

Can't you just use one of these plug in thyristor things we were prattling on about a few weeks ago?

 

I picked up a huge bloody variac today to see if its doable on my system before getting a smaller more appropriate gadget.

Edited January 31, 2023 by rusty69

[Tony1]

3 minutes ago, rusty69 said:

Can't you just use one of these plug in thyristor things we were prattling on about a few weeks ago?

 

 

Cheers Rusty- yes in theory, and I've got something I think will do the job. In fact, I even have an idea where to wire it in. 

But I do have nagging doubts about whether I might balls it up....

Tbh I'll probably  just bite the bullet, wire it in and give it a try once we get into Spring and the solar is picking up a bit.. 

 

ETA- do you have any links to one of these devices? 

 

Edited January 31, 2023 by Tony1

[rusty69]

Just now, Tony1 said:

 

 

Cheers Rusty- yes in theory, and I've got something I think will do the job. In fact, I even have an idea where to wire it in. 

But I do have nagging doubts about whether I might balls it up....

Tbh I'll probably  just bite the bullet, wire it in and give it a try once we get into Spring and the solar is picking up a bit.. 

 

The one biscuits linked to not long ago was a plug in device. I suppose it depends how big your immersion is. Mine is only 1KW, so its simply got a mains plug on, which as understand it will simply plug straight into a suitably sized thyristor gadget.

[Tony1]

1 minute ago, rusty69 said:

The one biscuits linked to not long ago was a plug in device. I suppose it depends how big your immersion is. Mine is only 1KW, so its simply got a mains plug on, which as understand it will simply plug straight into a suitably sized thyristor gadget.

 

My immersion is wired through a mains on/off switch, so there's no plug I can use for a thyristor. I need to use a device that takes in the live mains wire and throttles the current down a bit. 

 

 

[rusty69]

Just now, Tony1 said:

 

My immersion is wired through a mains on/off switch, so there's no plug I can use for a thyristor. I need to use a device that takes in the live mains wire and throttles the current down a bit. 

 

 

Ah,ok. Different from mine then. This is the thing we were talking about, but won't suit yours:

 

https://www.ebay.co.uk/itm/364094558085

 

And a link to the thread, with the same caveat I was given...use at your own risk.

 

 

[Tony1]

2 minutes ago, rusty69 said:

Ah,ok. Different from mine then. This is the thing we were talking about, but won't suit yours:

 

https://www.ebay.co.uk/itm/364094558085

 

And a link to the thread, with the same caveat I was given...use at your own risk.

 

 

 

Cheers- my long term wish is to divert power directly from the MPPTs into a 12v immersion heater coil thingy, instead of powering the immersion via the batteries and inverter- which I think will lengthen the battery life. 

But you also need a thermostat and heating coil that will work  safely with the highly variable 12v supply that you get from two MPPT units. I haven't yet seen  a suitable thermostat, but I think diverting the solar directly to the immersion is a sensible thing to do, as it  will help to preserve the life of these expensive batteries. 

Its on the long term 'nice to have' list.....

 

 

[rusty69]

3 minutes ago, Tony1 said:

 

Cheers- my long term wish is to divert power directly from the MPPTs into a 12v immersion heater coil thingy, instead of powering the immersion via the batteries and inverter- which I think will lengthen the battery life. 

But you also need a thermostat and heating coil that will work  safely with the highly variable 12v supply that you get from two MPPT units. I haven't yet seen  a suitable thermostat, but I think diverting the solar directly to the immersion is a sensible thing to do, as it  will help to preserve the life of these expensive batteries. 

Its on the long term 'nice to have' list.....

 

 

I don't remember the details now, but there is a YouTube video based on a design from the 12v boating group on Facebook. Design in the files section. Though I guess you've already seen that. 

Edited January 31, 2023 by rusty69

[Tony1]

Just now, rusty69 said:

I don't remember the details now, but there is a YouTube video based on a design from the 12v boating group on Facebook. Design in the files section. Though I guess you've already seen that. 

I haven't yet, but I'll take a look, thanks

[nicknorman]

I don’t think you need to worry about fast discharge of Li batteries, well up to 1C anyway. Fast charge might not be great but I don’t think there is a problem with fast discharge.

[LadyG]

On 10/05/2020 at 15:10, ditchcrawler said:

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

Mine was useless. On low it took eight hours to warm the food and on high it cooked anything solid after three hours.

[Guest]

6 minutes ago, LadyG said:

Mine was useless. On low it took eight hours to warm the food and on high it cooked anything solid after three hours.

 

Well I would say you need to read the manual.

 

Mrs M_JG regularly cooks great stuff in our slow cooker. Last Sunday we had a really juicy slow cooked chicken cooked in about 4 hours. 

 

She cooks delicious stews, soups, chill's, beef brisket, braised pork. The list goes on.

 

Of course yours could be faulty.

 

But I doubt it.

[Alan de Enfield]

3 minutes ago, M_JG said:

Of course yours could be faulty.

 

Or (probably) operator error!

[ditchcrawler]

11 minutes ago, M_JG said:

 

Well I would say you need to read the manual.

 

Mrs M_JG regularly cooks great stuff in our slow cooker. Last Sunday we had a really juicy slow cooked chicken cooked in about 4 hours. 

 

She cooks delicious stews, soups, chill's, beef brisket, braised pork. The list goes on.

 

Of course yours could be faulty.

 

But I doubt it.

I like a whole chicken done it or a joint of mutton. The wife drives it not me.

[Guest]

8 minutes ago, Alan de Enfield said:

 

Or (probably) operator error!

 

Possibly.

 

But to mis operate a cooking device with only three settings takes some doing.

3 minutes ago, ditchcrawler said:

I like a whole chicken done it or a joint of mutton. The wife drives it not me.

 

And you get the basis of a very nice gravy settled in the bottom too.

 

You dont get crispy skin of course but thats not an issue for us.

[CanalRiverHub]

We only ever use our slow cooker while on a full days cruise or there is guaranteed sun through the solar.

[Guest]

By coincidence.

 

Mrs M_JG's slow cooker triumph, cooked tonight.

 

Steamed Steak & Kidney pud....

 

 

Edited March 12, 2023 by M_JG

[Mike Hurley]

That looks great, did it taste as good as it looks?

[Kiwidad]

11 hours ago, M_JG said:

By coincidence.

 

Mrs M_JG's slow cooker triumph, cooked tonight.

 

Steamed Steak & Kidney pud....

 

 

That looks great, let’s have the recipe 😎

[Guest]

1 hour ago, Kiwidad said:

That looks great, let’s have the recipe 😎

 

Its essentially a Delia Smith recipe but instead of using a steamer Mrs M_JG stands it on a saucer in the slow cooker  (pre heated), add boling water to about half way up the pudding bowl, cook on high for 5 1/2 hours.

 

Shes tried the steamer method but it seems to hold together better if cooked in the slow cooker.

 

https://www.deliaonline.com/recipes/books/delias-winter-collection/steak-and-kidney-pudding-with-steak-and-kidney-gravy

 

 

2 hours ago, Mike Hurley said:

That looks great, did it taste as good as it looks?

 

Top notch, 

Edited March 13, 2023 by M_JG

[robtheplod]

something like this would get over all these issues wouldn't it?  Mr Ds Cookware – The Slow Cooker that needs No Power

[MtB]

1 hour ago, robtheplod said:

something like this would get over all these issues wouldn't it?  Mr Ds Cookware – The Slow Cooker that needs No Power

 

Clearly a case to Trading Standards to prosecute. 

 

Instructions for use: "Place the cooker on the heat and bring to the boil". 

 

In what way is this using no power? Just wondering...

 

 

[LadyG]

I've just been browsing in Sainsbury's today, and I discovered that one can buy slow cooker liners!

Saves on washing up, I presume. Who spends their life inventing these things? Is it on their c.v?

Edited March 23, 2023 by LadyG

[robtheplod]

4 minutes ago, LadyG said:

I've just been browsing in Sainsbury's today, and I discovered that one can buy slow cooker liner!

Saves on washing up, I presume. Who spends their life inventing these things? Is it on their c.v?

probably a bit like the heat proof liner you can put in your over floor - work great!