Hannah Barnes

Thank you so much Steve for the input. I had not thought of such an upgrade and I suspect it would be one I would need to work towards over a long term in terms of cost. Just a question with relation to this. I have nothing in my house that draws alot of power. As I was off-grid from the start all my appliances are geared for solar. The largest power drawer is my electric borehole pump (1.5kw) which I only pump when there is full sun. All my heating runs off gas and the rest is mainly the television and dvd player we use for the ministry as well as charing phones, laptops etc. and lights. That is why I have never gone for a big system. I already feel like mine is big enough, even for our weekend courses with 10 people, unless we hit 3 or 4 days of rain, which is very rare in Hoedspruit. It even handles my mom's oxygen machine running through the night and a fan when necessary. I also run a twin tub washing machine often with no issues. My biggest challenge is probably when there are 3 overcast days in winter but perhaps one more pylon tech and a few more solar panels (6 maybe) can sort that? I have in 7 years only been without power once (after we had 10 people there for the weekend and had to use the pressure pump for showering). Now I have a tank stand so the water is gravity fed and I have not ever again been without power. I have not had an alarm go off or changed a setting since Jaco did his magic and I don't have a battery monitor so I fly a bit blind feeling my way through on the voltage reading (which I know has its shortcomings but so far its been okay). 
So my question is, what would the benefit be to enlarging my system at a large cost in comparison to just installing another smaller system (3KW) at the ministry camp area to cope with a fridge, perhaps a freezer and some charging of phones, lights and other such equipment? I have an IBR roof at the ministry camp to mount solar panels on the outside kitchen and that could also be the central charging station for phones etc. as we pitch tents for the ministry. If I did then need to enlarge my home system at a later stage, could I not just put another 5Kva inverter in there that would allow me to run a series so higher watt solar panels? 
I am thinking that distributing the equipment also means not everything goes down if there is an issue with the main system. And it means that the cost is distributed in smaller doable amounts. 
Is there a scientific solar advantage to having it all in one? I am just curious. 
For now I will go with the generator but is there someone who could assist me then with the settings I will need to change on my inverter to charge the pylontechs via the generator if need be? I used to have good old golf cart batteries for 5 years and then I knew what settings to change but with the pylontechs I have not touched anything since Jaco installed them and did the settings in 2020 so I am nervous to mess with it all working so well. 

Hi Hannah, I think you have coped well with a small type of power requirement & looked after it well too. However, your assessment is quite correct in that, that many ppl will cause power trips to take place. 
On face value, this is what I see as 2 options ahead of you:
Replace the 5kW Mecer with its larger 10kW Voltronics same family inverter (MAX2 10kW). The advantages are two fold. You get double your power output & also you have 2 strings of MPPTs. That means you can leave the 1 string as the 270w panels & add the larger 550W panels onto the other MPPT string. Makes best of use of old & new. Also the 10kW MAX 2 can blend power much more efficiently than the older Mecer you have. 
However, it leaves you with a decision to make with your Pylontechs & Mecer machine. The Pylontechs are 0.5C capable batteries. Meaning you need to stack double the amount of capacity to unlock the full potential of 200A (10kW). The addition of another Pylontech is actually misleading because it will not allow you to withdraw 1C which is 200A available. At 100A the battery will allow that & any higher it will trip after a period of time. 
I am still a fan of 1C Lithium batteries & unfortunately Pylontech, falls way short on that & it doesn't pretend to be anything different. It just needs ppl to be aware of the discharge limitations. My go to solution for this is the Livoltek 5.1kWh lithium battery. 2 of these batteries unlocks the 200A required by the 10kW inverter. That leaves you at 10.2kWh of Lithium Iron Phosphate battery capacity. 
The answers to the above will lead you to the correct decision. 
Last but not least, get a Generator in the short term. 
I work in the Gauteng area, but can definitely assist you with a quotation on the equipment & installation I have mentioned above. 
The great thing you have done is opened this up to the community, more minds can lead to answers you & I don't see. 
 
 

How often will this happen? Would it be an option to just get a generator for the duration(s) of the conference(s), that can even be wired in as a backup for your household needs for the odd occasion you don't get by? Lower upfront costs versus higher running costs, but for an annual two-week conference a dedicated solar setup sounds overboard.

This confuses me. These are 6V batteries, so I would not expect readings of 13V and 7V, unless you are reading across two batteries. What usually happens is one of the batteries lose a cell. When that happens one of two things can happen, it will either read a higher voltage than the rest, or it will read a lower voltage than the rest.
One thing I know about is to add a tiny amount of Epsom salt to the battery. This increases the chemical reactivity and can squeeze a last bit of juice from a battery. Only, I feel very odd about even giving this advice. On youtube you will find several people telling you how to do this, claiming that it revives it completely and saves you thousands. Some even sell you documentation on how to do it (that is always how it works... sell the documentation, so if it doesn't work... it's not your product). It's snake oil. Also, I have no idea how much to use. What I do know is it buys a little extra time. Very little extra time. It's basically good for getting enough juice from an almost-dead car battery to last a few more days, but in a house battery I have no idea.
If the cell has gone dry, sometimes adding water and giving it a good charge can help. If the electrolyte is milky or brown in colour, it's usually over. At least (again), that is my limited experience.
No.
You will run into one of two issues. If the bad battery has an internal short and the voltage remains low (even while charging), the other batteries will end up being overcharged because the voltage divides unevenly due to the bad battery. This will kill them faster. Conversely, if the battery has a high internal resistance, then under charging that battery will show a higher voltage than the rest, and the rest will be undercharged. I don't want to be overly alarmist, but it will affect the others rather quickly, in the space of a week or two. Remember, the others are also long in tooth.
 

Hose them down with water. If the power goes up... then you know.

I don't think it will make a big difference. The water temperature in a  solar water panel is probably close to the PV panel and the heat transfer to the copper pipes without fins is poor.

Also this time of the year is not great for solar production, lots of moisture in the air. Depending on your panel angles, mid winter after a cold front you can get pretty high production.
It also depends on the load and SOC of your batteries. If your batteries are getting full around midday, the charging current will reduce.

Ha ha i need more than one line :)....part of a Christian ministry run nationally. We run the course in Limpopo one weekend a month on the farm at the moment.  

Awesome. Nice install!

Has anybody had any experience in this? Is it worthwhile/recommended to insure your solar system (massive investment). Is your system covered under general house insurance or would one have to specify your panels / inverters / batteries. should all components be insured or only some of the components like the inverter for example? would the insurance cost off set the savings in electricity costs so that it would make solar more expensive than Eskom / municipal in the long run.
any thoughts would be welcome and valued.
Many thanks
Jason

Hi All
I have 2 inverts in parallel 
1 x 4000va/5000kw model sol-i-ax-5m firmware-72.40 U2- 1.24
1 x 5000va/5000kw also model sol-i-ax-5m (think this one is actually a sol-i-ax-5p) firmware-72.61
8 x 220 AGM batteries 4 in series and in parallel with another 4.
8 x 260w solar panels on the roof all connected to the 4000va/5000kw also known as the pf0.8
They were not able to connect in parallel so I contacted the supplier and the send me firmware 72.61 to downgrade the new pf 1.0 machine and 72.70 to upgrade my old machine. After the fact I read that these two versions are not compatible either so I just took the old one back to 72.40.
I am not to sure if these are the best firmware for the two machines and now my batteries just go up to 50.3v max
Can I maybe use the same firmware on both machines?
Which firmware will be best for AGM batteries?