Inverter/battery recommendation

One can use a lower power kettle to boil the water more slowly:

Takealot.com: Online Shopping | SA's leading online store

South Africa's leading online store. Fast, reliable delivery to your door. Many ways to pay. Shop anything you can imagine: TVs, laptops, cellphones, kitchen appliances, toys, books, beauty & more. Shop the mobile app anytime, anywhere.
www.takealot.com www.takealot.com
 
Olorin said:
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
Click to expand...

You could probably get away with less power if for example you only powered a router and an iPad or laptop (non gamer).
 
Olorin said:
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.
Click to expand...
Can anyone please comment on this?
 
Olorin said:
Can anyone please comment on this?
Click to expand...

Long story short, AC Pure sine and inverter Pure Sine dont match 100%. The compressor need to stop before it starts again.

The reason this exists as well.

DC doesn't care or see the sine so anything with a transformer can handle a 10-20ms switchover depending on the size of the cap over DC + and -.
 
AlphaJohn said:
Long story short, AC Pure sine and inverter Pure Sine dont match 100%. The compressor need to stop before it starts again.

The reason this exists as well.

DC doesn't care or see the sine so anything with a transformer can handle a 10-20ms switchover depending on the size of the cap over DC + and -.
Click to expand...
Thank you for the technical explanation. What I don't understand and maybe you can explain is that this issue doesn't happen if the switchover takes place between battery power and Eskom, it only happens when Eskom power switches to battery power.

So basically if I purchase one of those devices you linked to, I shouldn't have this problem again when switching from Eskom power to battery?
 
Olorin said:
Can anyone please comment on this?
Click to expand...
Some equipment is more sensitive than others i suppose it is dependant on its
Power Supply quality

For mission critical stuff you can get a ups that doesn't have a switchover ie it is designed with a twin power type layout ie so if eskom disappears it is as if nothing has changed but most backup power inverters tend to have a switch over , those that know models that aren't can chime in
 
Olorin said:
Thank you for the technical explanation. What I don't understand and maybe you can explain is that this issue doesn't happen if the switchover takes place between battery power and Eskom, it only happens when Eskom power switches to battery power.
Click to expand...

Eskom -> Inverter = Unplanned so no time to sync
Inverter -> Eskom = Planned so Inverter can sync before the switch.

Olorin said:
So basically if I purchase one of those devices you linked to, I shouldn't have this problem again when switching from Eskom power to battery?
Click to expand...

Nope that plug prevents motor burnout via 5 Min shut-off before restart. Ie: it forces the Fridge compressor motor to stop before starting again.
 
Olorin said:
Can anyone please comment on this?
Click to expand...
Age of device too
Certain components do age ie especially if the caps are
al cheapos

So they go dryer and eventually become less and less up to the task. Until they pop

Salt
 
leon.davibe said:
Age of device too
Certain components do age ie especially if the caps are
al cheapos

So they go dryer and eventually become less and less up to the task. Until they pop

Salt
Click to expand...
Well my AVR is 6 months old, its not that old. :)
 
AlphaJohn said:
Eskom -> Inverter = Unplanned so no time to sync
Inverter -> Eskom = Planned so Inverter can sync before the switch.



Nope that plug prevents motor burnout via 5 Min shut-off before restart. Ie: it forces the Fridge compressor motor to stop before starting again.
Click to expand...
Your explanation re Battery to Eskom makes sense, thanks for that! Are you an EE, or just technically informed? :D
 
Ϲhristopher said:
2.6kW is pushing the battery close to it's limit though?
Click to expand...
Apologies, system is NOT pushing 2.6KW with the kettle running, not sure why I said that. I just checked now, TV on, laptop on, light on, kettle running, I'm at 2.3KW.
 
AlphaJohn said:
Long story short, AC Pure sine and inverter Pure Sine dont match 100%. The compressor need to stop before it starts again.

The reason this exists as well.

DC doesn't care or see the sine so anything with a transformer can handle a 10-20ms switchover depending on the size of the cap over DC + and -.
Click to expand...
some power supplies are switching ie has no transformer

for that this might help if it bothers you enough or find an old psu that is heavy (weight often equals transformer) in a drawer with the right voltage you can use one with more A rating but not less output

 
I am SO confused. How does all this KVA stuff work, one electrician said 3.5KVA, another 5KVA
for Lithium batteries and Inverter to run:
small house lights, TV, 2 laptops, Wifi router and OTP and Fridge I think he said
Whilst I understand the high energy pull of a Kettle or Heater and Washing Machine / Dishwasher, surely I could get capacity to use a Microwave for just 5mins at least?
THAT would be ideal to me

Is this possible and anyone have a setup where you are able to use your Microwave for just a few mins?
 
TheTwo said:
I am SO confused. How does all this KVA stuff work, one electrician said 3.5KVA, another 5KVA
for Lithium batteries and Inverter to run:
small house lights, TV, 2 laptops, Wifi router and OTP and Fridge I think he said
Whilst I understand the high energy pull of a Kettle or Heater and Washing Machine / Dishwasher, surely I could get capacity to use a Microwave for just 5mins at least?
THAT would be ideal to me

Is this possible and anyone have a setup where you are able to use your Microwave for just a few mins?
Click to expand...

That is because you asked them how long a piece of string is.

For example I have 2 TV's
- 40" use 50-70W (depending on brightness)
- 58" use 120-200W (depending on brightness)

Or 2 laptops in the house
Wife 45W
Me 90W

So just saying You have a TV & laptop means zip

The best advice to get the proper size is to use something like a Kill-A-Watt and work on actual, anything else is pure guesswork.

Oh and a microwave can be anything from 900W-3000W depending on size and model.
 
TheTwo said:
I am SO confused. How does all this KVA stuff work, one electrician said 3.5KVA, another 5KVA
for Lithium batteries and Inverter to run:
small house lights, TV, 2 laptops, Wifi router and OTP and Fridge I think he said
Whilst I understand the high energy pull of a Kettle or Heater and Washing Machine / Dishwasher, surely I could get capacity to use a Microwave for just 5mins at least?
THAT would be ideal to me

Is this possible and anyone have a setup where you are able to use your Microwave for just a few mins?
Click to expand...
So there are two factors here. The peak amount of power it will provide, and the total amount of energy available in the battery. The two are related it not the same.

Microwaves aren’t all that much lighter than kettles. Mine pulls about 1700W, compared to a kettle which is about 2kW. So if your microwave is similar to mine, you should be able to get away with a 3kVA inverter. But if anything else is switched on, you will be cutting it fine.

As @AlphaJohn mentioned, it’s best to measure what your load is. Then you needn’t worry about the quality of information that you get from randos on the internet.
 
Okay so I resolved my issue with the AVR switching off when transitioning from Eskom to battery power. This is what I did - I went into my inverter settings and switched from APL mode to UPS. The default setting is APL.

Problem solved - no more switching off when I'm load shedded.
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X