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Take the 100% SOC down to 98.9% due to say a Microwave. If SOC is set at 70% to auto start gennie, you will net be bothered if you switch on the kettle and as with "... went down on my SOC for the night to 78.8% where I normally go down to 81%.", it is not 70% SOC, so gennie never starts.

You grid tie guys are so spoilt!  100% SOC is only reached once a day in an off grid scenario.

41 minutes ago, The Terrible Triplett said:

 I wonder now like with cars temp gauge, you drive and next moment the engine car seizes, overheated. Why did the manufacturers not add a alarm buzzer on temp gauges?

Reminds me of my 1994 VW City Golf I got as my first car. Pulled the stock 1.3l and replaced it with a 2.0l fuel injected motor (what a difference and no more 4 speed manual). Changed all the radiator hoses except for the 1 steel pipe (stupid). Half a year later n remember flooring it around a corner, next moment red lights and buzzers and I see the temp gauge in the red. Stomped on the clutch and turned of the ignition immediately. Lucky for me I could free to a garage. Jumped out and just saw this huge pool of water. Lucky for me I only blew the head gasket everything else tested

39 minutes ago, plonkster said:

Some manufacturers do away with even the heat gauge and add just a warning light. Even for those who still have the gauge, I often question how useful it is: it normally sits there plastered to the middle of the range (in a Toyota at least) and when things go wrong it usually shoots right to the top, I actually cannot remember the last time I saw an engine running "slightly" hot, generally it's already quite binary, things are either fine or they are not. So maybe the warning-light people have a point.

This is something that still gets me with the car (4 years later and I still find myself looking for that gauge). I was so used to stare at that thing in the middle.

29 minutes ago, plonkster said:

For such integration work, I would probably always back-up the BMV with battery voltage (10.5V per 12V cell? Better shut that down sir regardless of what the other guys think...).

I'm sure most inverters will have this. I know the Axpert does have this as one of the settings

4 minutes ago, viper_za said:

1994 VW City Golf I got as my first car. Pulled the stock 1.3l and replaced it with a 2.0l fuel injected motor

I had a 2000 model 1.4i. I can only imagine what a 2-liter must feel like (stole it from a Polo, right?).

It was technically the wife's car but she hated the stiff clutch, so I would drive it to work and back. There was something incredibly endearing about that little pocket rocket. I believe it made around 65kw officially, but often more in practice, and that was in a body that weighed a mere 750kg. If you drove it like an old man, it would give you 13km/liter. Man, that's what my Diesel sedan does in town...

My advice: You want to save money, buy an old Citigolf 1.4i. Cheap to service. Good fuel economy :-) Forget the Diesel...

7 minutes ago, plonkster said:

16ms transfer time

And that is why I use a online UPS. Got really tired with the lovely one and hers when the choir starts voicing their interest when DSTV, TV and Pi goes "off" when system swaps between Eskom and solar. Your case, why not put the Pi on the batts direct?

 

11 minutes ago, plonkster said:

you set the MPPT with safe default charge parameters no more than 13% of the Ah rating

Where do you set this on Victron controllers ... wait, Victron Connect has the setting!!!

 

8 minutes ago, plonkster said:

Better shut that down sir regardless of what the other guys think

That is normally done by the inverter by default, not so?

45 minutes ago, DeepBass9 said:

You grid tie guys are so spoilt!  100% SOC is only reached once a day in an off grid scenario.

No grid tie. I am off-grid, with Eskom as backup, only once a day I get few hours of 100% SOC. 

Have to carefully manage the load evenings to ensure I stay above 80% DOD.

Where I have Eskom, in off-grid, you would have a gennie. 

9 minutes ago, The Terrible Triplett said:

why not put the Pi on the batts direct?

Cause I did not have a handy buck-converter lying around at the time, and it was safer to have it isolated on the AC side during development of the canbus stuff. Now that I'm using the isolated canbus transceiver, I feel a little safer about attempting this. I have a space buck unit left from my recent under-counter lighting project. Would prefer a current-limited model though. Some time...

9 minutes ago, The Terrible Triplett said:

Where do you set this on Victron controllers ... wait, Victron Connect has the setting!!!

You can configure it using the mpptprefs software or victronconnect. It uses the same register numbers at the end of the day, just different ways of getting there. Even the can-bus models use the same "register numbers", it's just a different transport layer.

 

9 minutes ago, The Terrible Triplett said:

That is normally done by the inverter by default, not so?

Yup. Within the context of starting a generator though... perhaps look at both the BMV SOC and battery voltage to be safe :-)

27 minutes ago, plonkster said:

I had a 2000 model 1.4i. I can only imagine what a 2-liter must feel like (stole it from a Polo, right?).

Was a custom built motor. Originally 1.8 VW Golf 3 bored out and fitted with 2.4 kombi pistons if I remember correctly. Worked out to about 1987cc with really high compression.
Fitted it with a 8 valve Polo head( bigger valves, ported intake/exhaust, knife edged crank, Mr Turbo fuel injection, you name it, it was done) made 99kw 320Nm on the wheels on the dyno.
Only way to get more was to add some gummy berry juice and run a different map.
I eventually had to get rid of it as replacing starters and clutches killed me. I used to have a spare started, could swap that thing out in 15-20 min and be on my way again.
Since I used it as a daily driver I had to rip out the racing clutch as jumping meters in traffic was not working and leaving that 2meter gap in front of me for this was always an invitation for someone else to try and squeeze in. So normal 2.0l clutch had to do replaced it every 3-4 months as it just starts slipping.
Great thing about this was I never got less than 12km/liter

Replaced this with the 1.4i Velocity and man did this thing feel so slow, and now the Polo 1.2 TDI Bluemotion (slowest of them all) but this gives me 18-20km/liter combined cycle and 22-24km/liter highway.
@Weasel I miss that blue golf, it ate 330i's for breakfast. Weasel could never see this as I had a little problem with the front passenger seat. When you floor it I always saw weasel staring at the roof lining of the car. The first time that happened was so epic, I could not stop laughing

 

2 minutes ago, viper_za said:

Polo 1.2 TDI Bluemotion (slowest of them all)

Problem with the modern cars is they have grown too fat. It's all about the power to mass ratio. Talking about stock vehicles, even the 1.6i Citigolf was a fast little bugger, though of course nothing like your home-made beast.

I actually like the occasional dice against a citigolf, I would like to say I left them in the dust but it would be more like leaving them in clouds of Diesel soot... :-P That little family-man-special of mine with the 2-liter Diesel engine does 2kw more than the 1.6 petrol and double the torque. Pitted uphill against a 2-liter (non-turboed!) Audi the Audi will lose. I suppose it is nothing to brag too much about, but I love cars that punch a little above their looks, that is to say, sleepers :-)

15 minutes ago, viper_za said:

Weasel could never see this as I had a little problem with the front passenger seat. When you floor it I always saw weasel staring at the roof lining of the car. The first time that happened was so epic, I could not stop laughing

En nou kan ek ook nie!!! 

1 minute ago, plonkster said:

even the 1.6i Citigolf was a fast little bugger

They used to say that there was only one 1.6i faster than the 1.4i Citygolf and that was the 1.6i Citygolf

 

3 minutes ago, plonkster said:

I suppose it is nothing to brag too much about, but I love cars that punch a little above their looks, that is to say, sleepers :-)

You made me derail this thread so far. I just have to do this now. Sorry @PaulF007
My sleeper

Then I realized I need to do the bakes too

18 minutes ago, viper_za said:

My sleeper

Now that's a proper sleeper. You don't see it coming.

Actually diced a Mk6 GTI yesterday, not because I thought I had any chance, just for the heck of it. GTi is like 8 seconds to 100, mine is more like 10 (and a bit), but if you wind up the rpms just right it's actually slightly faster off the line.

Anyway... one day when I'm done playing with the solar stuff and have money again, I'm getting me a little VW rabbit shell and doing this properly. I have a buddy who drives Gymkana with a 1.4i... that thing makes well over 90kw by now, lightened flywheel, custom fuel injection, racing clutch, you name it.

Hahahahaha 

Glad to have been able to supplied a platform that could develop eventually into cars and things. Me my self arent much of a car guy - its is a mode for getting from point a to b and I own one of the best cars EVER made 

 

This should get most of you petrol heads attention - --- --- --- it is the one that is paid off and where I dont owe a cent  

Back to the discussion at hand. - My take on all of the info to sum up after some new guy has read through all of this.

To consider whether you want to go 5kva or 3kva should not be determined by your budget but rather by your needs. There is absolutely not shortcuts or easy ways out even more so if you go completely off grid.

If you skimp on the batteries you will either burn them very quickly or going to burn a lot of expensive fuel ( Some look around on a 5kv gennie you are looking +/- R25 per Hour) 2016

If you skimp on panels - same as above

Skimp on inverter ------- nah not going there to open a hole new can of worms , just read the above comments and you will notice that there is very different opinions.

As for me -

1st) Work out what is the bare minimum that I will need to get through a "normal" night might end up with just lights and some quality family time

2nd) Work out what you will need during daytime assuming that you have full sunlight - This will be drived by the panels

3rd) What is your expected peak need after you have worked sequential - This could be like heating your geyser or in my case working on the Lathe / Welder over weekends

Ask the guys if you have missed something (please add what I most certainly have missed)

Once you have all the info you can only decide whether you should go 5kva or 3kva because the maths will give you the answer you can then also get creative with auto gennie and what-nots.

We live in a "google" generation where if you need info you dont have to go lookup the "Werld Spektrum" and read through all the pages to get the info (Given my age away) as a result info is expected to be popcorn just one click and all should be there to be implemented - now I have also gone philosophical-

Begin small to grow your system to quote TTT even if it means that you need to go by candle from time to time (This might even please the misses) 

Should we call this one or is there more to add?

I would rather start a new thread where I could start with the basic planning and end with my personal ideal system should give the other new newcomers a good idea of how to start.. 

 

I vote to keep it here, the next person reading this thread from the start, will see how it evolved.

The Victron self-consumption white paper is one I often referred to. Their methodology was to first look at things that are on all the time. Alarms, gate openers, garage door openers, the Dstv PVR, the pump in the fish pond, etc. Tally those up. Next look at all the stuff that are always plugged into the same socket. Washing machines and dish washers and bed lamps and televisions, not on all the time, but they don't move between circuits. Add those up. That gives you the bare minimum you need. Now you can decide how much more you want to go for, when do you deem it acceptable to start the genie. Back in the 80s on the farm, if extensive vacuuming was done, lots of clothes needed washing (weekends with kids coming from boarding school) or you wanted to use the old springbok meat saw... you started the genie.

Sent from my GT-I9195 using Tapatalk

Amen brother, amen. 

Come to think of it, we had a 3.75kva Hoffberg single phase generator. How on earth did we get by with so little? :-)

20 minutes ago, plonkster said:

How on earth did we get by with so little? :-)

Think about it ... 

1 minute ago, The Terrible Triplett said:

Think about it ... 

It was a rhetorical question :-)

4 minutes ago, plonkster said:

It was a rhetorical question :-)

Maybe it was, but if you recall my needs and wants posts... makes a huge difference in solar costs.

Your parents did the need thing quite well.
Us today do the want thing very well. 

10 hours ago, viper_za said:

@Weasel I miss that blue golf, it ate 330i's for breakfast. Weasel could never see this as I had a little problem with the front passenger seat. When you floor it I always saw weasel staring at the roof lining of the car. The first time that happened was so epic, I could not stop laughing

hehe ja, i thought i broke your seat the first time round

not to derail the topic again  onwards.

10 hours ago, The Terrible Triplett said:

Your parents did the need thing quite well.

It's easy when you're working bottom up, riding the technology wave from the other side. When you come from a time with paraffin lamps, paraffin fridge, wood stove, the good old "donkie" for heating water using fire, 3kw is actually a luxury! It's like Bill Gates' 640kb joke: Who in the world would need more than that!? Then came the technology, first three truck batteries for lighting in the evening. The engine would run every morning to recharge the batteries and so the big minus-40 cooling-bank freezer could run (it had these huge tanks it would cool down which would then keep it cold until tomorrow). In 1983, Television came to Namibia, and we got the first "Sigma" inverter, a little 200W (or thereabouts) MSW jobbie. Then the first energy efficient things: A Bosch fridge (still in working order today) and an AEG Arctis Öko freezer (those things are still the best today, but almost unaffordable). Those AEGs had an Achilles heal: Aluminium piping that corroded. But even by today's standards they were amazing, they had a 110W compressor and needed to run 6-7 hours a day. This is mid 80s people! Along with that came the first battery bank (350Ah Willards), 12 M-Setek solar panels (googled them the other day, still in business) at 33W each, wired in strings of 3 (because we had no MPPTs back then, even PWM was unheard of).

The biggest problem was usually when your girlfriend comes to visit and she cannot use the hair dryer. Thankfully she didn't hold it against me and became my wife some years later :-)

Must have been a exciting journey for them. Respect. 

Today she will hold you responsible ne, they grow and become wiser, these wife's of ours. And much more tolerant too, but only to a point.