Abe53

Thanks very much for the very useful and complete response, TaliaB ! That is exactly what I wanted to hear. Will implement such. And yes, strings are identical and all panels mounted at 45 deg to horizontal. (E-W Tepee style, cheap, no mounting frame needed) Yes, I know about 30 deg being supposedly optimum, my reasoning is 45 deg optimizes for winter, also panels should wash cleaner with rain and have less risk of hail damage. (We are near Pretoria) Now if only we could get more sunshine... ;-) Best regards, Abe53.

Hello to the Victron fundi's! Interesting question re max PV on charge controller: SmartSolar MPPT RS 450/100 with 2 arrays E-W each 8 x 460W panels mounted 45 deg to horizontal. Want to add a North-facing array, but no free MPPT. Could E + W arrays parallel on one MPPT? (Cannot put 16 panels in series, 16 x Voc = 624V, max spec 450V.) Panels Imax 14A but would rarely exceed 10A on both E + W. . Now, sticker on controller says 20A max, but manual is all over: on P10: Max operational inbput current for each tracker is 18A, but also: Connecting PV arrays up to maximum of 30A. on p47: Max operational PV input current 16A per tracker, yet also: Max PV array size per tracker 7200Wp (450V x 20A) . What would happen if available current exceeds 20A? If it clips, fine, midday loss of no concern, but might it overheat? No use asking a Victron agent, they will play safe and say no go.... Answer by PM if you prefer.

We have several off-grid installations requiring geyser control, some with old hardware, and have unreliable wi-fi coverage which rules out Internet of Things. Scorp007 's proposal of using a XH M602 charger should work, I use buck converters with similar up-down buttons to charge DIY li-ion batteries to fine tolerances. Will tinker and revert. Thanks again for your attention in this matter... ;-)

Good morning all and best for 2026! As the title alludes to, how do you switch the geyser off when battery volts drops? Yes, there are expensive Home Assistant, Geyserwise and such solutions, but there surely are cheaper and simpler ways? How about an analogue adjustable DC Volt sensing switch that energizes a relay? I cannot find such a gizmo, although such should find a ready market. Surely some electronic tinkerers have built it already? Thought I would find it at instructables.com but not. Any other websites I can look? Thanks for your attention in this matter... ;-)

Hello julle, typically thrown away, but would be worth gold to me. Office type UPS 5 to 10 kW 230VAC but typically 180 V nominal DC which used 16 x 12V LA battery banks. (Not economical to replace) I built a solid 200V 10 kWh Lithium battery but my Eaton 9PX 5kW UPS has now retired. A 10kW UPS was given away on another forum but I was too late to dibs. (wonder if that UPS is even in use now...) Willing to pay copper value+. Bought an Eaton 15kW UPS but that runs on 400V DC. Before re-configuring my powerwall, thought of asking around for a direct replacement. Centurion area, but will collect anywhere in Gauteng.

Hi Gary and Calvin, perhaps either could answer a vexing question regarding ESKOM metering? 3-phase medium user, 350KVA supply ESKOM direct. Used to have access to meters but metering was changed to direct radio reporting and box locked. Would like to monitor usage to audit account, but have no access to meters?! Is Eskom compelled to provide customers access to electricity consumption meters or not?

Solar is the perfect DIY project to wean yourself off the grid particularly and guavement in general. "Ons doen dit self!" A great advantage is that the user will do the best job he/she can, (no wokes here), learns the system from inside out, and reaps the benefit of reliability. Also can troubleshoot problems and fix it. Few if any call-outs. YouTube is the great leveller, has saved me plenty. No, I do not believe everything there, but have common sense. Stories about bad and indeed dangerous installations by supposedly "professional installers" abound. Instead of attempting to upgrade all installers and force their use, I think it would be better to educate users on how to do a good install themselves. It is not rocket science. Yes, get a safety inspector if you do not trust yourself. It is the prize sponsors prerogative to make the rules for the competition and rub up to the trade, but it will not endear them to the end customer.

Hi Carl, Yes, would like that Leaf for the 20km school run. Will send detail by PM. Have excess production on my solar PV to charge with. Am in Gauteng but flying down to Cape for the holidays. However, will have to send the leaf by trailer...

Hi Rolf, congratulations on your build, savour the savings! Today re-read the thread but think you still have not answered PowerUser's question on configuration completely. How are the cells connected? How many parallel at any stage? The reason I ask, is that with stage 6 load-shitting hitting us unawares, some of my 18650 builds did not power through 4-and some hours as they should, which demanded urgent maintenance. I found even the best packs lost cells here and there, this far only 5% attrition, but with my 14s architecture it often meant 50% strings lost per tray. Suspect the dreaded filament growth causing internal discharge. How do you manage that? Regards, Abe53 (yes, I am 70 this year and thought I was retired, working hard as ever....)

Yes, I have just the place for those 270W panels. PM sent with contact detail.

Watching from the sideline, amused... Pylontech seems known to run their batteries hard. 15 cells vs 16 and such. One of my systems have 2 x US3000 on a Victron inverter and I occasionally see slight over voltage warnings, duly ignored. My standard installation 14s 100p 18650 Li-Ion cell batteries (don't laugh, they work very well) run a very conservative 44-55V profile regulated by the inverters, sans BMS. When I occasionally don my BMS hat, I sometimes replace a few cells, but then, they are virtually free... Ran a 53s 34p backup bank the other day and thought to check health: 34 changeover switches to the 100W test load makes that easy, and not a single cell needed changing. NMC chemistry still rocks! My 12yr old Samsung laptop still has 3 hour battery life. (Used Samsung battery management, 80% max.)

All warm and fuzzy feelings, cudos to Magneto, but may we know what the problem was and how it was fixed?

Done. Would also like to see statistics when available?

Good evening Occuplus, nice build, but please clarify " # of cells in pack" ? Are these wired in parallel? In which case you have a 5p 24s battery, which is very different to a 24s 5p battery, or do I have my nonmenclature (sp?) wrong way around?

Hi Treshen, if I understand correctly, I am with your "junior sparky" and also think earthing PV frames to a separate earth rod which also serves the PV SPD's makes sense. Several installs like that on our farm with both switching and transformer based inverters, many lightning storms, no problem. P.S: what is your opinion on lightning prevention instead of, or in addition to lightning diversion? Dissipation Array Systems (DAS) and Charge Transfer Systems (CTS) seems to use different language but much the same principles.

Hi Pierre D, Why worry? They call the DC powered home "Edison's revenge." Eventually lights (LED's are native 3VDC) and most electronics just reduce 220VAC to 12VDC anyway.

Hi Jason, the usual installation has the inverter supplied from grid before the RCD (Earth leakage) The earth leakage is then downstream from the changeover source grid/inverter.

Good evening from our home powered by 18650's in Ph6 loadshedding. P1000, do you perhaps drive a car with a tank full of incendiary fluid? At speed in close encounters with taxis driven by reckless maniacs? (They say heaven welcomes taxi drivers, they convert more heathens than the priests... 😉 Yes, 18650's have a small risk of overheating and burning (not exploding) if mismanaged. However, I minimize the risk by: 1. Testing all cells, checking temperatures by hand and with a laser meter while charging at 1A, weeding out the heaters. (The red Sanyo's are the usual suspects) 2. Using them very conservatively, low cutout at 3.1V, charge to max 3.9V (4.25V allowed) Draw max 1A (<0.5C) Charge max 0.5A 3. Fitting every string with a 4A fuse. (Yes, once popped 36 fuses when switching on big loads with only three trays of 14s 10p batteries on the wall.) 4. DC rated CB and fuse on + and - 5. The 18650's are not soldered, just butted + to - (after mangling the + to protrude) contained only by a 25x16mm PVC trunking, if disturbed, the battery just falls apart cutting the circuit. I have survived 69 years with some close encounters, not at all worried about the thousands of 18650's on the wall in the passage.

Just an update on the health of my first 18650 powerwall: Have not checked the 53s 34p for the last year but coming home at sunset in load shedding (blackout) I switched to the Eaton PX9 because son wanted a pizza and I wanted to spare the Solis's 14s 100p for in case EKSDOM did not come back . With oven, microwave, kettle and more, the wall only dropped from 206V to 199V after dinner. So I switched off all strings and checked them today. All 1802 x 18650 cells at healthy Volts and pulling their weight, nice to see! No BMS, no pumping up or drawing down, every cell finds its happy place.

Hi Richard, where will inverter be installed? If noise might be an irritant, consider a silent inverter. Noise down the passage did not bother me, but did irritate my wife. Changed to silent inverter, and will install silent as standard in future. Was taken to task for saying that I read they use better components and have longer lifespan. Poster reckoned they run hotter and will fail sooner. Beg to differ, they do cost a little more, but have huge heat dissipater aluminium fins and can afford using higher spec components and design to keep cool. Eventually a fan will fail.... You did mention future-proofing. Why then not 2 x 5 kW inverters in parallel? Costs not much more than one 8kW and gives redundancy. A Sunsynk 5kW model is available fanless, as are many Solis models.

Goeienaand VirWat, (My vrou kom van Welkom, die weerlig daar is erg..) To accommodate the language-impaired, I will continue in British 😉 Good evening gents, Re: Lightning prevention. Should solar arrays perhaps grow metal whiskers to prevent lightning strikes? Any comment on "Dissipation Array Systems" (DAS) and "Charge Transfer Systems" (CTS)? From my reading these use different language but the same principles. . https://www.lightningprotection.com/...us-prevention/ . http://www.electrical-knowhow.com/20...on-System.html . https://www.oedigital.com/news/45744...ore-structures . https://zandz.com/en/lightning_prote...htning-strike/

Good evening Gerald, Yes, might have use for that Microcare charge controller. Am offered a Microcare inverter at a decent price but the accompanying charge controller can only accommodate 150VDC from PV. If yours is the 250VDC model, will check if the inverter is still available and then buy your charge controller. With even 5kW inverters these days sporting 450VDC input, one should allow for higher DC volts, makes wiring so much easier.

Hello Suds, get a silent inverter. Silence is golden! I also read that silent inverters use higher specification components and better design which promises longer life.

A stolen battery? 😉 Hat, coat, door...

Hello Don, which Growatt inverter have you? I bought a used 5000 ES and installed with a homebuilt 18650 powerwall with no BMS and it works fine. Perhaps change settings to user-defined battery? Check those volt readings with a handheld multimeter while inverter is acting up?