Inverter/battery recommendation

Olorin said:
Just an update on the system for people that maybe aren't aware - so on a 3KVA inverter this is what I had running simultaneously on Friday - TV, 2 lights, fridge/freezer, AVR and my laptop - AND on top of that I used my kettle.

Doing all of this I'm at 2.59kw. So still a little bit of overhead, but I just wanted to give people an idea that it's possible to use a kettle which I was told by every other company is a NO-GO on a 3KVA. Now I live alone, so maybe that helps, but the only things that are disabled through the inverter are my stove/oven and geyser.

On a 2 hour+ load shedding event, of the 5 bars available on my inverter representing full charge I only used 1 bar. That was using my TV, AV surround sound system, 2 lights, and also boiling the kettle twice within that 2 hour period.

I'm quite chuffed that for the most part I can live my life without having to make any major alterations on a 3KVA system. The only thing I'll need to get is a gas hob for cooking - I have a portable unit, but a built-in would be preferable.
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What batteries are you using and how old are they?
 
Olorin said:
Hubble AM-4. Brand new. They are 1st life cells, whatever that means. :D
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1st life haven't been used before. 2nd life are batteries that had a life before, most likely in an electric bus or something.
 
Olorin said:
Just an update on the system for people that maybe aren't aware - so on a 3KVA inverter this is what I had running simultaneously on Friday - TV, 2 lights, fridge/freezer, AVR and my laptop - AND on top of that I used my kettle.

Doing all of this I'm at 2.59kw. So still a little bit of overhead
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2.6kW is pushing the battery close to it's limit though?
 
Ϲhristopher said:
2.6kW is pushing the battery close to it's limit though?
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yea though his inverter can go to 3kw
what he could use for an extended period ie not spike for a few seconds depends on where his battery bms cuts on overload

the whole notion of not using a kettle or other heating device is perpetuated without any supporting info

if you boil the kettle you sacrifice the same amount of power for that 5 min that will power the tv/internet lights etc for an hour

ie what is more important 1 more hr of that vs the coffee

in our house the coffee wins every time, if you have spare capacity have a cup

edit : naturally on lead acid peukert losses means you may be trading 1.5hrs for the cup naturally above was based on lithium, nobody should be using lead acid for load shedding imo
 
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Use microwave to warm up a cup of water. Still less power Draw then boiling kettle.
 
AlphaJohn said:
Gonna require the same amount of energy. Using different formats just gonna expand the time access.
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Might just be about limiting it to exactly 1 cup,as opposed to absentmindely filling yout kettle. Energy use will scale with volume of water
 
PsyWulf said:
Might just be about limiting it to exactly 1 cup,as opposed to absentmindely filling yout kettle. Energy use will scale with volume of water
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Can do the same with a Kettle In fact we do it all the time when we use a gas stove.

The argument stands, you will always use the same amount of energy to boil the same volume of water.

Edit: actually above is a lie, when you start working with efficiencies, a kettle would be better as energy loss in the form of heat will also go into the water minus the radiation. Microwave conversion heat loss gets vented out the back.

Edit: On Subject.
1682332518912.png
 
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AlphaJohn said:
Can do the same with a Kettle In fact we do it all the time when we use a gas stove.

The argument stands, you will always use the same amount of energy to boil the same volume of water.

Edit: actually above is a lie, when you start working with efficiencies, a kettle would be better as energy loss in the form of heat will also go into the water minus the radiation. Microwave conversion heat loss gets vented out the back.

Edit: On Subject.
View attachment 1513615
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Pfft, microwave is definitely mo better, especially when you re-heat a cup of Frisco that has gone cold.
 
Microwaves are horribly inefficient in my experience. Even good ones use about 1.3-1.4 kW (I've measured at the wall) to deliver 900W of heating into your Frisco.

Kettles have much higher current draw, but most of the energy goes into the water.

Come to think of it, that's an interesting experiment to try. I'll have to get my meter back from the friend I loaned it to and try out a comparison.
 
Something which I've discovered and I don't know if this is normal or not, but I've noticed whenever the system switches over from Eskom to battery, my AV receiver tends to switch off and back on again. I don't know what the correct term is, maybe cycles? I can hear it switching off, it takes 3-4 seconds, then it's back on and I have sound as before.

Is that normal behaviour? I would have assumed the switchover time would be instantaneous - I don't have any weird issues with my TV, or my lights, or anything else. It's just the AV receiver that switches off and on again when changing to battery power.
 
leon.davibe said:
yea though his inverter can go to 3kw
what he could use for an extended period ie not spike for a few seconds depends on where his battery bms cuts on overload

the whole notion of not using a kettle or other heating device is perpetuated without any supporting info

if you boil the kettle you sacrifice the same amount of power for that 5 min that will power the tv/internet lights etc for an hour

ie what is more important 1 more hr of that vs the coffee

in our house the coffee wins every time, if you have spare capacity have a cup

edit : naturally on lead acid peukert losses means you may be trading 1.5hrs for the cup naturally above was based on lithium, nobody should be using lead acid for load shedding imo
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Exactly, every expert I spoke to said that a minimum of a 5KVA inverter would be necessary if I wanted to use the kettle which is clearly BS. The thing is, I only boil enough water for one cup of tea/coffee at a time so the kettle won't take 5 minutes to boil, it takes less than 2 minutes.

Now if I had a wife and kids and they were doing their own thing, boiling the water and then deciding to use the microwave at the same time, then a 5KVA is definitely required.
 
Olorin said:
Exactly, every expert I spoke to said that a minimum of a 5KVA inverter would be necessary if I wanted to use the kettle, but the thing is, I only boil enough water for one cup of tea/coffee so the kettle won't take 5 minutes to boil, it takes less than 2 minutes.

Now if I had a wife and kids and they were doing their own thing, then it would be a problem. All it takes is for someone else to use the microwave and maybe a hair dryer simultaneously and then you know you f*ked up. :)
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You yourself indicated you are skirting the line when it comes to max

I would recommend a 5 to most people too just because babysitting things to the watt isn't for everyone
 
Olorin said:
Exactly, every expert I spoke to said that a minimum of a 5KVA inverter would be necessary if I wanted to use the kettle which is clearly BS. The thing is, I only boil enough water for one cup of tea/coffee at a time so the kettle won't take 5 minutes to boil, it takes less than 2 minutes.

Now if I had a wife and kids and they were doing their own thing, boiling the water and then deciding to use the microwave at the same time, then a 5KVA is definitely required.
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The inverter isn't your only limitation though, if you have a Hubble AM4 (2.6kWh, 1C), then you are basically at the limit.

The 5kVA requirement is very arbitrary though, it's not as if all kettles consume the same amount of power.
 
PsyWulf said:
Might just be about limiting it to exactly 1 cup,as opposed to absentmindely filling yout kettle. Energy use will scale with volume of water
Click to expand...
Ok maybe i was ocd before loadshedding i boil only exact quantity i need bar safety margin Naturaly
 
PsyWulf said:
You yourself indicated you are skirting the line when it comes to max

I would recommend a 5 to most people too just because babysitting things to the watt isn't for everyone
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I agree, if I were to buy again knowing I'm going to stay in my apartment for another 4-5 years minimum then I'd definitely go 5KVA. I'm just surprised that I can get away with a 3KVA and not completely sacrifice all the niceties. Barring oven/stove. :D
 
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