Brendonvdh

I would like to comment on running PCs from 12V.  Firstly, let's tackle laptops.  Laptops normally need 19VDC, but some use 18 or 15VDC.  You can buy 12V laptop chargers that replace your 230V laptop charger.  There are some models that can run from 230VAC and 12VDC.  DO NOT BUY THESE.  I brought one and one look inside convinced me not to even try using it.  The build quality and circuit design is pathetic to say the least (!)  For instance, the battery input has no local smoothing capacitor, thus sending high current switching noise all along the battery wires, acting as huge antenas for EMI/RFI radiation.

However, you can buy a boost converter such as this one: https://www.communica.co.za/products/bmt-dc-dc-booster-12-35vout-150w?variant=31667841040457 for less than R 100.  They are of excellent quality.  Before getting my inverter, I used to run my laptop from such a device.  After 2 hours of operation, the heatsink stays ice-cold.  I really have a hard time registering any increase in temperature.

Many monitors and some of the smaller TVs also use a laptop-sized external power supply.  These tend to also run mostly from 19VDC.   So you can use the same boost regulator to power monitors/TVs.  The biggest headache is to obtain the correct DC plug, as there are many different shapes and sizes.  I had to revert to buying a cheap replacement power supply, just to strip off the DC lead.

I myself brought a 21" Mecer monitor which can actually run from 12VDC.  Many years ago, I also brought a cheap Sinotec TV, again for load shedding purposes - where I could run straight from a 12V battery.  The higher supply voltage of a float-charged SLA battery, of around 13.85V should not be a problem for a 12VDC specced device.

Desktop PCs are a problem.  I would not fiddle and replace the ATX PSU.  I went a different route.  If you want/need a desktop, buy yourself one of these miniPCs.  They are normally the size of a paving brick.  Lenovo, HP, Dell, etc. all make these.  Because of their small size, there is not enough room for a mains operated PSU and they are fitted with a DC socket.  Again, most (but not all) run from around 19VDC using laptop-type power supplies.  You can buy an older 2nd/3rd generation i3 or i5 second hand for about 3K or you can pick up the latest shiny, new, i7.

Remember that just about all electronics operate inherently at low voltages of 12 / 5 / 3.3 / 1.8 volts.  It is totally silly to take 12/24/48VDC, convert it to 230VAC just to down-convert it back to 5V to charge your phone, or power your laptop, or even drive a LED light.  An Axpert inverter has an idle consumption of between 35 and 50W.  It would drain a 2.75KWh lithium battery 100% in less than 4 days, by doing nothing else but keeping itself warm.

The boost regulators have a wide input voltage range, normally 8V to about 32V.  There is a preset potentiometer that allows you to adjust the output voltage, typically from 15 to 30V or thereabouts, but being a boost regulator, the input voltage must always be lower than the required output voltage.  Communica has even sold a 600W boost regulator that can create up to 80VDC output.  I brought one of these to play with.  I paid approx R 230.  Sadly, these have been out of stock for more than a year now.

Hi 
I have a small pool (5m x 3m) and the AC pump is on its last legs.
I am thinking of replacing with a DC Solar Pool pump system like this:
https://tripplehydro-energy.co.za/store/500W-Spitfire-Solar-Pool-Pump-p486390423/?utm_source=googleshopping&utm_medium=shp&utm_network=x&utm_mobile=0&utm_creative=&utm_position=&utm_random=9500005138093320644&gclid=CjwKCAiAzp6eBhByEiwA_gGq5IddvU_2X7SrERwosRFxBYbBUV3L47WCvCTrK8FXB9xvCNwWNMT19xoCJ0gQAvD_BwE&utm_campaign=smart shopping - za (1)&utm_ad_group_id=962217&utm_campaign_id=1002462&utm_prod_id=486390423
Anyone installed something like this? Any advice or shared experiences would be appreciated
A 1KW AC pool pump running 6 hours / day = R18/day R6750/year. So this system would pay for itself within 2 years so seems like a no brainer unless I am missing something?
TIA

My understanding is that legitimate Axperts (which could have a vastly different name, like a Kodak OGPlus) are made in the Voltronic factory, whereas clones are copies made in other factories in China, using stolen firmware and a schematic diagram reverse engineered from the real thing. The clone maker might understand the reason that an expensive part is used, and use a similar quality one, or they might just throw together any cheap junk and rely on the reliability reputation for the genuine Voltronics. They might use identical firmware, or reverse engineer it and make improvements. They might or might not avoid land mines (e.g. fault code 90) that Voltronic have put into their firmware to trip up the clone makers.
I don't believe that this is the case, although we know that some customisation does happen, e.g. the Inverex series. Someone posted recently that the same company that sells Inverex inverters also sells some non-customised Axperts under a different label. My guess is that Voltronics don't always have the time to customise every model. and/or the reseller doesn't always want to pay the extra for customisation, for smaller segments of the market.
At one point, it was clear that EASun was a clone maker; there is still a web page up by MPPSolar (one of the earliest and I think largest resellers of genuine Voltronics machines) that says so. But recent evidence strongly suggests that at least most EASuns are now genuine.
Some inverters, e.g. by Must Power, started off as poor quality clones, but seem to have evolved into their own models with different capabilities from the original Voltronics models that they copied from. I don't know what the recent build quality is like, but it seems vastly improved from what it was.
Companies like Growatt make models that are strikingly similar to some Voltronic models, but again, they seem to have evolved and improved.
All this makes it really hard for the poor consumer to know what to buy.

OK so after spending many hours in this rabbit hole I have decided not to go for a 5kW system 😀
I realised a 3kW system is like half the price and will backup 80% of what I would have done with 5kW
A 3kW system is just much more bang for buck in my case. 
It will still cover all lights, TV, alarm, router, computers and alarm which is all I really need.
and I can add solar later, it will be a smaller and simpler install, and a quicker return on investment.
This is what I am getting:
2 x  Hubble S-120 1.5kWh 12V 120Ah Lithium Battery R14000
https://www.geewiz.co.za/lithium-ion-batteries/153798-hubble-s-120-15kwh-12v-120ah-lithium-ion-lifepo4-battery.html
1 x MUST 3KW 60AMP/MPPT SOLAR HYBRID INVERTER R5500
https://www.solarwaysuppliers.co.za/product/must-3kw-60amp-mppt-solar-hybrid-inverter/
thanks everyone for the responses and tips so far.
I will give an update once I got this system installed.

OK so after spending many hours in this rabbit hole I have decided not to go for a 5kW system 😀
I realised a 3kW system is like half the price and will backup 80% of what I would have done with 5kW
A 3kW system is just much more bang for buck in my case. 
It will still cover all lights, TV, alarm, router, computers and alarm which is all I really need.
and I can add solar later, it will be a smaller and simpler install, and a quicker return on investment.
This is what I am getting:
2 x  Hubble S-120 1.5kWh 12V 120Ah Lithium Battery R14000
https://www.geewiz.co.za/lithium-ion-batteries/153798-hubble-s-120-15kwh-12v-120ah-lithium-ion-lifepo4-battery.html
1 x MUST 3KW 60AMP/MPPT SOLAR HYBRID INVERTER R5500
https://www.solarwaysuppliers.co.za/product/must-3kw-60amp-mppt-solar-hybrid-inverter/
thanks everyone for the responses and tips so far.
I will give an update once I got this system installed.

I have Municipal account data since June 2008.
Our monthly electricity use has been fairly stable till June 2022 when my PV panels became a factor.
Average monthly usage based on 30.5 days for 24 months till June 22 (before PV) was around 425 units or then about 14 units per day. Were only 2 persons in the house and use power conservatively.
Since June 2022 this has decreased slowly to 9.36 units per day for Sept 22, that equals a saving of 4.64 units or 33%
I have been considering this, it seems a relatively small saving if I consider that many days the solar provides nearly all the electricity the house needs during daylight hours.
If I then convert the saving to Rand it actually looks worse (4.64 X 2.88 = R13.38 pd = R408.18 pm) This would be a pretty reasonable saving, but it is not true when I look at my account as there are all kinds of Factors effecting the actual amount, of which the crucial one is a fixed charge portion of the electricity account. There has also been a tariff increase. My monthly saving has in actual terms taken from my account only been about R150 pm.
The fixed portion of the electricity account is only set to increase as more people decrease their electricity consumption.
Only my stove and oven are outside the inverter, so that is a given that I can not influence and for the past month I have done everything possible to run the house fully from the sun, even my geyser when I am at home.
Although the monthly saving is not crucial, it does play a role and seems to be much less then I had reasonably anticipated. In coming month I expect to increase my saving somewhat, but will see.
I also notice I seem to be using much more grid electricity then others, but “if you use little you can only save a little”
I must compare the readings from my inverter to those provided by the City.
I pay the City of Cape Town.
 

Hey PRP
I been stuck in this rabbit hole for the last week already. The more you look the more complicated it gets.😆 
I average about 13kw/day usage
I started with plan for a budget 5kw backup system, best price I could find was about R45K installed, and was battling to justify the cost. 
In the end I have decided to go for a 3kW system, about R25K installed, which will cover our lights, internet, TV which ticks enough boxes for me.
You use a lot more electricity than me so will get a ROI sooner
A system that can save you 300-400kw/month is probably closer R100K I think? so ROI like 7 years @ R1200/month (by my very crude calcs.)

I been crawling the interwebs for good deals. It is amazing how many suppliers are out there, and some of them are clearly scams 
Best deal I found is:
Growatt SPF5000ES with Wifi dongle R12500 / ellyhillpower
Dyness 4.8kwh li battery R24000 / jcsolarpanels
R36500 Total
Its probably not the best time to be looking for deals in the middle of stage 4 when everyone in SA is shopping.. 🙄

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OK so after spending many hours in this rabbit hole I have decided not to go for a 5kW system 😀
I realised a 3kW system is like half the price and will backup 80% of what I would have done with 5kW
A 3kW system is just much more bang for buck in my case. 
It will still cover all lights, TV, alarm, router, computers and alarm which is all I really need.
and I can add solar later, it will be a smaller and simpler install, and a quicker return on investment.
This is what I am getting:
2 x  Hubble S-120 1.5kWh 12V 120Ah Lithium Battery R14000
https://www.geewiz.co.za/lithium-ion-batteries/153798-hubble-s-120-15kwh-12v-120ah-lithium-ion-lifepo4-battery.html
1 x MUST 3KW 60AMP/MPPT SOLAR HYBRID INVERTER R5500
https://www.solarwaysuppliers.co.za/product/must-3kw-60amp-mppt-solar-hybrid-inverter/
thanks everyone for the responses and tips so far.
I will give an update once I got this system installed.

Plan is to add panels within a couple months, starting with 2 or 4 and add when money is available.

My experience tells me that you want to be sure that batteries and inverter will get on with each other. Specifically you need working comms between BMS and inverter so that your battery gets an accurate SOC and so the BMS can send the correct settings to the inverter. So check the combinations here. All the battery manufacturer web sites should provide information as to what inverters they are compatible with.

Thanks you are right, no sure why I didn't look their properly before.
Best deal there is the LuxPower R 12,144.00 and Revov R100  R 22,719.40 total R34863. Very good deal.
Now to try figure out if the LuxPower can talk to the Revov BMS..

The Revov is a "second life" cell. You can read on their site. https://revov.co.za/2ndlife/r100-2ndlife-battery/ 
The warranty and specs are still very good, so for me it seems to be the best budget option.
Other thing to consider is if the Growatt will talk to the Revov BMS.. still looking for a definitive answer on that. 

I been crawling the interwebs for good deals. It is amazing how many suppliers are out there, and some of them are clearly scams 
Best deal I found is:
Growatt SPF5000ES with Wifi dongle R12500 / ellyhillpower
Dyness 4.8kwh li battery R24000 / jcsolarpanels
R36500 Total
Its probably not the best time to be looking for deals in the middle of stage 4 when everyone in SA is shopping.. 🙄

Also a Hubble AM-2. Original version with original Firmware. 382 cycles so far with zero loss of capacity. Very satisfied.

All three of the listed options have that feature, so would come down to the other factors. (Although, as a pure backup solution, even that does not matter.)
I recently had to make a similar decision.  First choice would have been the Growatt - but recent firmware updates apparently bias it towards high fan speed (noisy). Never considered the Luxpower, as I do not know enough about them. So went with the Kodak. So far it works perfectly, but only a few years will tell w.r.t. reliability.
The other important consideration was the warranty - Growatt (5 year), Kodak (3 year), Luxpower (2 year).  Would again have biased me to the Growatt, if it wasn't for all the noise complaints.

Luxpower has the advantage of two MPPTs, which makes it more versatile into the future for panels facing different directions.

The Cell technology used in the Greenrich batteries are not your normal Prysmatic Pouch Cells these batteries use High Density Cylindrical cells so the internal look of the battery is very neat and tidy and looks professional and definitely not home-made.
The benefit of this is the batteries are a lot safer because if one cell fails it does not set the cells next to it on fire.
The battery also has internal fire protection as you can see from these photographs the battery did not catch fire or explode the pictures speak for them selves.
Note the condition of the metal test bench after the fire test the metal got so hot it deformed so they really blasted the battery with the flames.
Please note this was done in a controlled safe environment by professionals so please do not try this at home.