Darrenf

Also just got confirmation I am on single phase

Amazing thanks Mzezman, apprecaite the help! I will feedback with the usage asap.

HI there thanks for the reply, to be honest I don't even know what 3-phase details I do not think I require this I just want to power the household so open to any suggestions.
I have also not done a power audit but I will do this so I know what kind of usage I have. I am pn pre-paid so i will take a heavy usage day (usually weekends) and determine what usage I have.
Thank you!

Personally I would much rather sell you a decent Victron system, or direct you to someone who can help with that. I am unfortunately not clued up about where to buy these other brands, I sometimes see those trolleys at Builders Warehouse, and I know they come without batteries.

My experience with this is that you have basically two groups of batteries. You can buy below 5k ZAR or above it. Now most people are going to buy the cheaper battery because they just spent 9k-10k for the inverter-trolley... so quite understandable the spectre of increasing that investment is somewhat adrenaline-inducing. But the trouble with those cheaper batteries is that they just don't hold up, regardless of how well you treat them. One year in, maybe 18 months... there you are with one bad cell neatly packaged with 5 good ones, and no option but to replace the entire bank.
Treat them badly, eg discharging them too deeply, and you're looking at not even 6 months.
If you buy a good AGM battery though, and you treat them well, you could well be okay for 3 years or more. And by good I mean something like your Victron AGM or Gel batteries.
However, what happens to most people is that once load-shedding stops, you forget to look after the batteries, until the next time load-shedding starts. In an ideal world just keeping the batteries floated should be all you need to do (it's a UPS after all, right?) but for some reason those cheaper batteries seem to develop one bad cell despite being treated well, and it goes unnoticed until the next time there is an outage.
Now again, in my experience, the 200Ah battery space tends to have better quality, it sort of rises above the cheap fray. But you cannot fit two 200hAh batteries into those trolleys, and as a result, people who buy those trolleys generally have a bad experience. Not because the trolley is bad, but just because of the neighbourhood it lives in... 🙂
 

🤔... grabs screwdriver while geewiz branded watt meter starts looking nervous...

late to the party but brought my own drinks so will hang around in the parking lot...and in the spirit of "give a man a fish blah blah... but teach him to hot wire a car..."
EDIT: @Darrenf noticed I bombarded you previously with my rambling, you are welcome to ask for more clarification/explanation 🙂
Don't worry about total household consumption since you only want to power a couple of very specific things.
Ideally get some form of power meter (about R500 from what ever your flavour of online shop)... .or less ideal check each "appliance" for the label that shows you the power rating (like a 2000W kettle).... or search online for general estimates since many appliances don't actually list the power rating (my TV does not... but I checked my 47" (OLD school, not OLED) TV, AV amplifier, android TV box thingi, and B315 router all combined average about 125W).
Add all the various power requirements up and you will probably not even pass 500W (but if possible check your own numbers). So you could probably get by with a 500-800W inverter.
Now multiply the total power requirement by hours you want to power it for. 4h * 500W =2000Wh - this is technically how much energy you will need from a battery to power these things. Because energy conversion is not perfect and to allow some extra room, add an efficiency factor of 80%.... devide the 2000Wh by 0.8... 2000Wh/0.8 = 2500Wh will be a safer number to work with.
Here is where things can seem to become too technical but soldier on...., batteries will specify their voltage (12V, 24V, 48V most common) and their storage ability (in either Amp hour (Ah) or Watt hour (Wh)). Lithium batteries often specify the capacity in Wh and lead acid batteries in Ah. So how do you decide if a given battery will be "big" enough? Lithium just compare the Wh numbers. For lead acid (like the adds posted in this thread) take YOUR Wh number and devide it by the listed battery voltage. The first add has a single 12V 100Ah battery. So...2500Wh/12V = 208Ah. You will need a 208Ah 12V lead acid battery to power 500W for 4 hours - so a single battery like the one add will not be enough since it is a 100Ah battery. You can connect two 100Ah batteries in parallel then you will have a 200Ah but still 12V battery, so two of  those batteries might be needed (or maybe two 60Ah batteries?....read on first).
The second add says it comes with 2 batteries.... but if you check the specifications you will likely find that the inverter works on 24V (the two batteries are connected in series), so you have a 100Ah 24V battery (even though it is made with two 100Ah 12V batteries).... will the 2 batteries be big enough?... 2500Wh/24V = 104Ah... so this is closer.
BUT lead acid batteries do not have a very long total life before they "break" if you tend to use more than 50% of their capacity. So if looking at lead acid battery systems you will make life simpler if you take your power requirement and double it from the start. 2500Wh * 2 = 5000Wh.... 5000Wh/12V~400Ah.... or 5000Wh/24V~200Ah. So whether you go with 12V or 24V you will need at least four 100Ah batteries (or eight 50Ah batteries or two 200Ah batteries). Lithium batteries will generally let you use about 90% of their capacity but lithium is heavy on the pocket (depending how you do your sums)
I attached an excel sheet which can help you play around with some numbers. Change the battery voltage and time (in red font) as you need/want and add your appliances+watts in the yellow columns to the list. Since this is about load shedding you should also look at things lile time available to recharge the batteries (the sheet will show you how much time you need depending on the charger capacity to recharge the battery). Use at own risk (do not use it to make calculations to power grandma's iron lung)
Any of the mentioned systems should meet your inverter requirement but I suspect you will end up with a flat battery often and/or have to buy new batteries after a couple of months.
The "off-the-shelf" solutions can generally be made up cheaper by just combining everything yourself. I would personally not install the Axpert inverter laying flat though (like in the add)... pretty sure the unit thermal regulation was designed around a vertical install. If you can change a plug on a toaster you should be able to make up a system - especially for your listed needs. If not comfortable doing that - no shame in that (and stay out of the DB!).
Another option to the miriad of "ready made" UPS type systems that you can look at in your budget is something like a DIY victron multiplus 12/800 inverter charger (R8500-9500) combined with a second life Mecer 200Ah/2500Wh 12V lithium battery (R6400-R7500). Add a victron Mk3 USB cable (R1200) so you can make some changes to the inverter settings from a laptop. Get a battery place to make you up some 25mm2 cable with properly crimped lugs, add a fuse between battery and inverter, put it on trolley in a box (make sure the battery terminals are at least covered) if you want and you should have the lightest, least intrusive system that should meet your power needs in terms of inverter power, fast enough charger for most load shedding scenarios, and with a bit of careful load management your total storage capacity should be enough.
The axpert type systems definitely are lower cost and simpler (no extra cable/laptop needed for changing settings) and you have a screen to see what is happening. Especially the 3000W inverters give you more options to power something like a kettle if you really need to (not gonna do that with a 800W any inverter). The axpert type systems also generally add the option out of the box that you can add solar panels later without needing any other bits than solar panels, solar cable and solar fuse/disconnects.
If you think/gamble that load shedding will only be around now-and-again for a day or two and you want to keep this grudge purchase as cheap as possible, then also consider just battery, a separate smallish inverter and a loose battery charger. (keep charger connected to battery, when load shedding comes around, hook up the inverter... when load shedding goes away again for 3 months... put inverter in cupboard). Here you will just lose out on the automatic/"seemless" switch over when load shedding happens that you get with the axpert/multiplus type systems.
If going axpert type system - try and make sure it is an original voltronic produced inverter (quality and support on the clones seems somewhat iffy).
last thing... Just a note on having any system next to the TV... all these systems contain fans that switch on at least when charging the battery at a high rate and possibly when powering the load... you could find that it bothers you if right next to the TV.
whoop-whooop...that's the sound of the police... off I go..
LoadShed_Calc.xlsx

Those things are quite excellent! They use some Chinese chip called the v9261f. Big Clive did a test too. And there are guys who hacked these to interface them with an ESP32 so they can talk to an mqtt server.
 
Agreed. The loads mentioned will get you a 50% DoD (estimated, by me) on a standard 2 hour load-shedding slot, and on the double-slot (level 5 and up in Cape Town, but much earlier in Jhb) will see you run out just about every time. The standard batteries people use with those 24V Mecer trolleys won't last 3 months with that kind of abuse.

Two questions:
1. How easy would it be to isolate those circuits you absolutely require? It sounds like they are all just plug circuits, but they might not be on the same circuit.
2. Will you be able to keep your load low on those circuits when Eskom is available? If not, you’ll need something with a high AC transfer ability.
Your backup needs don’t seem to be very high, and for the basics you have listed, you’d probably be able to get away with a relatively small battery. However, your budget is somewhat limited especially since you would need to get an electrician as well to install and CoC the whole thing. The cost of that would be case specific but a second DB would be required, for example.

If you want something that does not need to be installed, and all your essentials are on one plug, you might want to look at one of those portable trolley inverter kits. This one from takelot is just an example, I don't have personal experience with it. It will run you under R15k for the inverter and 2 deep cycle batteries.

This one will do all that you want and more. Just keep it plugged into the wall and your devices into the inverter and it will change over automatically.
https://www.geewiz.co.za/long-run-ups-inverter-battery/93614-1030-mecer-axpert-3000va-pure-sine-inverter-2x-100ah-battery-8-hour-battery-life-kit-3000w.html#/132-battery_type-100ah_standard_200_250_cycles
 

You just need a UPS. Those Mecer's aren't bad UPSes. Though of course I'd still love to rather sell you a small Multiplus, like the kits Sustainable have (comes with a LiFePO4 battery with significantly better cycle life).
Must say though, I love how the above ad advertises an 8-hour battery life without saying what kind of load it can do for that 8 hours. If your total load is under 300W, and you kill the batteries completely every time, then yes, you'll be able to do 8 hours. Your max continuous load will be around 500W (that would give a pretty steep C/5 discharge rate on the batteries).
500W should be sufficient for the appliances you listed though.

Sorry! I completely missed the second paragraph of your original post. Yeah, one of those portable UPSes would be perfect. No need for installation! 😄
Like plonkster said, a UPS with a lithium battery will give you much better longevity. If Eskom is going to go into multiple load shedding cycles every day and you need something to last you a long time, a lithium battery option would be better. They are of course more expensive so you would need to do a bit of a cost benefit analysis.