introverter

learning opportunity for me - apologies... Problem: If cloudy weather and the generator is supplying power to inverter for powering base (house) load and doing a bit of battery charging on the side. Now switch on kettle and the temporary overload causes the inverter to disconnect from the generator and switch full load to batteries (after a couple of unsuccesful attempts to re-connect to the generator). Solution: Remove battery charge "decision making" and battery charging load from inverter and move to separate battery charger still connected to the generator. Question: If all conditions remain similar (cloudy, house base load the same, batteries same level of discharge etc.) Unless the separate charger is way more efficient (or smaller?), why will the generator total load when switching on the kettle not still lead to a generator load to the point of slowing down and causing the inverter to disconnect?

If definitely going the 48V lithium battery route and planning to cycle the batteries (discharge and recharge) every day for more than a year I would close my eyes and hope the more expensive new batteries (pylon or dyness or whatever) will live up to their claims of 6000 cycles. The Mecer batteries are so called second life batteries (reclaimed from E-vehicles etc) and when combining 4 them to get to 48V I think you are adding to the gamble of cells not being balanced etc. 4 x mecers probably R28000 (?) with roughly double total capacity of 2 X 50Ah Dyness/pylontechs at R30000-R35000(?). Mecer warranty 2 years with expected cycle life of 1500 cycles. Pylontech/Dyness 7/10-10 warranty with claimed 6000 cycle life. So unless the total capacity is the make or break factor I am not sure the mecers represent that big a bargain for this application where hoping for longevity in the expected design life? If not yet done, get something like this and just confirm your load (often is lower/higher than the appliance label indication) and look for ways to reduce load (do what you can with the laptop and try to minimize the PC etc)... maybe you can get away with one of the 75Ah lithiums (R21000-R25000?) for now and upspec on the inverter/solar.... you can add more batteries later if needed.

or come to a stop..... to fill-up the petrol tank again...😬

No.. I was in the future where you upgraded to lithiums 🙂. I come from the perspective of battery fully charged as backup supply being the priority. With the voltage discharge curve of lithium being so flat if the charger thinks the battery is still fairly full (based solely on voltage) it does not inniate a bulk charge (think most inverters work on battery @ float voltage minus X to decide to start bulk). So if you do not have a way for the inverter to accurately know SOC and no other interactive BMS integration but you want to make sure a bulk charge is started every day then if you have a fairly predicable load you can use the float voltage setting to achieve that. But if your (lithium) battery is quite large and you use only 10-15% during the night the voltage could still be quite high so a smaller battery where you end up at 50% DOD or more could make life simpler (and unlike the lead acids the 50%....80% DOD line is not that anxiety provoking).

I think you may be mixing up some concepts or your neighbours are hooked up to your electricity supply and they are miners (bitcoin or zama zama). My entire house (including electric geyser, electric oven, electric pool pump, etc) use about 400-500 kWh in a month. If your TV uses about 100W, PC 300W, Lights 50W, Router & Laptop 50W, your combined power draw is 500W, which for 1 hour will be 500Wh , and for 6 hours will be 3000Wh or 3kWh per day between 4pm-10pm. (the just Watt (W) part is probably a bit more relevant for the inverter size and and Watt-Hour (Wh) for the battery size... based on your looking at 2 x 50Ah batteries you probably meant to type a 500W load ...you got the right numbers just not the correct units (which can leed to very different and waaaayyyy more expensive advice). The problem you have is that the lithium batteries are fairly new in South Africa (Dyness probably a bit newer than PylonTech) so the chance for people to have had lots of problems and report it on forums like these have been limited. Looking through the forum it seems like there are more problems in setting up the batteries with different types of inverters than any clear problems of batteries breaking. That is why you also need to look carefully at the inverter and what that support is like (firmware upgrades etc). About setting up a system that should last 10 years... no one locally has had these batteries installed so long and with the way the world is going the best we can hope for is that the companies will be around even 3 years from now. In your situation (municipality issues), if it was me, I would try to take a bit more time and seriously look at a plan to get as much as possible off the grid - so a smallish generator might not be such a bad idea for now (gives you power while the municipality and eskom hopefully sort something out and you have a backup no matter what system you decide on for the future).

that sucks big time Is this your average monthly electricity bill or daily? Someone at home during the day cleaning house/cooking? Fridge/freezer running? When getting home at 4pm do you then need to cook with electricity or is it mainly to have some light, tv and keep fridges going?... any of the things that heat up (kettles, stoves, heaters) will drive up what you need for battery use, so looking at things like gas cooking could also be worthwhile. If the load on the batteries during the day is very low or non existent and depending how much you take out of the batteries between 4pm-10pm you may not need solar to charge the batteries.. My bad I cannot speak to who honours their warranty easiest but keep in mind the lithium warranties do not mean the battery will last 10 years. The warraties generally mean that if the battery is used in a certain way that it should still have about 80% of the capacity that you started with.

My suggestion: forget about what you can get (makes and names) and first figure out what you need. Are you without mains/grid/(eskom) power every day for 12 hours or is this for when there is load shedding or do you once every couple of weeks not have mains/eskom eletricity for a day and then it is back for 2 weeks? If you are without electricity everyday is it always during the day? you need to know how big the maximun and average load is that you need to power... do you want to power a whole house (business/office) where you power the kettle, oven, TV, lights or do you only want the TV/computer and a couple of lights to work?. There is quite a bit of difference in price and what you can do between 5kVa and 3kVa inverters. If you put 2 x 12V batteries is series (like the mecers) you end up with 24V battery which should make some 3kVa inverters options but for 5kVa you will need 48V batteries... if you only want to power a TV and couple of LED lights you might not even need 3kVA... You need to know what the average power draw will be on the batteries and also what the minimum time is that you will have available to charge them again to know if the inverter/charger can charge them quickly enough... you also need to check if the battery will allow to be charged as quick as you need. just because a battery can charge at 50A does not mean it is a good idea...especially if you want the battery to last as long as possible Cheap and quality very seldom go together. The inverter and solar panel part probably have the potential to last longer if nothing bad like lighting/hail etc. happen. Batteries (lithium or any other kind) are less likely to see 10 years.

Even though I take some sales brochure claims with a bit of salt I definitely think a very effective way to increase your monthly electricity bill is with an electric geyser. My first preference remains to first look at ways of decreasing demand/use since it gives an immediate saving at very little cost but there is definitely a point where it becomes impractical (with children...teenagers maybe impossible?) and then if one has the means to look for alternative sources to use that (again if working with an already constrained budget lower demand should translate to smaller outlay on whatever the solution is). If I reduce my shower time any further I suspect other people will start maintaining more than 2m social distancing....

@Richard Mackay, seems like you are in the 20-25% range too. Like @calypso I am somewhat wary of the "geyser is an unseen MONSTER" perspective. By the way, another interesting (and lively at the time) discussion on the matter of geyser gadgets and tricks over here. In our case we have no heat pump, no solar; also no timers/external control/logic devices (not sure if the brain should count as a device...). 150L kwikot (3kW element ) geyser, thermostat set to what is indicated as ~50 degree. Geyser under pitched tile roof above insulated (thermoguard?) ceiling. Geyser (loosely) fitted with (not the best) geyser blanket. No insulation on any pipes but also no pipe runs exposed outside house. Efergy energy meter (only updates every 6 seconds) connected to geyser circuit - compare with total house kWh numbers from measurement on mains breaker. I believe that we are however now at the limit of what savings can be had purely by adapting our use/habits related to the geyser. In terms of adding PV to our geyser it will likely only make any significant contribution to reducing eskom costs if suspending heating of the geyser by about 15:00-1700 (?) every day will still leave us with acceptably warm water by the next morning. I will still try to simulate sun light hours only heating with manual geyser switch offs now that we are heading into winter to get a sense of standing losses in worst case scenario in our case but when left to fend for itself our geyser does not (h)eat much during the useful PV hours. Running only on Eskom (no timers etc.) this is what our average geyser element activity looks like (i.e. most days/graphs look something like this). The small green "speed humps" indicate no electricity consumption. but sometimes we get this and other times this not much heating happening between 09:00-17:00...and there are some indications that even during mild weather the element is generally called on to "top-up" the water temp somewhere between 03:00-06:00 before any water is drawn. Something that the variability in our graphs also make me wonder is, other than potential ambient condition differences, whether some geyserwise related savings are actually due to the geyserwise thermostat/temp probe maybe being more accurate/consistent than standard thermostats...

What I was hinting at (very badly) is that if (some of) the batteries are a bit knackered it is not necessarily strange as they went through more charge/discharge than just the "over night consumption" (even if the rate of discharge was low). Different age batteries and the premature float issue probably had bit of slow decay that you may not have become aware of seeing how little of the overall capacity you tend to use? Any how let me get out of the way of trouble shooting the existing battery bank and remind you of solutions to problems you do not yet have. 😉..😈.. DC-DC converter? Seems like the "interactive" comms between even the pylontech type lithiums and the inverter are not mandatory . Have a look here . While refering to 48V the following could give you something to work from. I do think that if very accurate display of SOC is important you will probably benefit from some form of BMV/shunt. If just wanting to make sure that the battery is charged after and ready for the nightly discharge (sheesh that sounds wrong) then experimenting with especially the float setting should get you there. The advantage of the lithiums here are that you do not have to really fear straying over the 80%..50% DOD line (with a 24V pylontech, based on what looks like a fairly predictable 40-50Ah capacity requirement you should be hitting about 50% DOD).

Short answer: Do not have one. Looks like you could possibly save some money with something like the geyserwise PV conversion but there are many variables to consider. longer sermon: Overall I assume the goal is to save money (compared to not having hot water if there is no Eskom due to load shedding etc)? If yes, just first try and check if the geyser is such a big contributor as you think and if it is also look at ways to improve it without installing any devices yet. If you can monitor electricity consumption of the geyser in relation to your total electricity consumption you could find that the geyser uses less electricity than you think (and therefore slower ROI assuming the geyserwise/PV will cut that part of you electricity use dramatically). In our 2 person family the geyser is only responsible for about 20% of our electricity consumption.... Something like an Efergy energy monitor can be useful (if you are able/comfortable putting the current transformer (CT) part into your DB). I quite like the more basic version that does not connect to the internet buut there are a number of alternatives available. If you go the Efergy route, getting the the "three phase" kit can be a more cost effective way to be able to measure 3 different circuits (not at the same time though) without having to move the CT around the whole time). Cost will be around R1500+ which many people can not/prefer not to spend since they are trying to spend less money in the first place. If you already know they geyser is the biggest culprit that you can do something about then something like the geyserwise looks like it could save you some money after a while. Just keep in mind that even if 10 people post here that they made huge savings - it may be less/more in your case. Your local weather will influence if nothing else the theoretical availability of at least sun light to help in the first place (also differences like geyser not well insulated?... average temperature of water entering the geyser maybe much colder than for other people?..prefer geyser temperature at 70 degrees while others prefer 50 degrees ...other people take 5 minute showers but you prefer 2 hot full baths every day...etc). Your usage pattern of hot water from the geyser will also influence it. If you use water from the geyser in the morning then solar has most of the day to warm up the new water without using eskom (even if the weather is a bit crappy). If you then again use hot water in the late afternoon and/or during the night then the geyser may have to use eskom to warm up the water for the morning.... the links from @Richard Mackay and @Louisvdw are well worth looking at.

100% agree. When reading through the thread I just remembered that I came across what seemed like a lead-acid only warning somewhere. Think those of us more cautious in nature will quite easily draw the "do not risk lithium" conclusion.

Disclaimer: other than reading Axpert manuals and lurking on forums when doing pre-purchase homework I do not know much about the Axperts and their various incarnations Wonder if the batteries ended up working harder/more often than thought or often(ish) do not complete a charge cycle. With the base load going and using something like an induction hob (1000-2000W?) even with good sunshine the batteries may get tapped unless "output source priority" is set to "utl"? Slow cooker adding 200W-400W(?) for couple of hours to base load... Even in the King manual 😉 The "dumb"/drop-in replacement type lithiums generally should be okay with any inverter/charger if you can set the Bulk charge/float voltage and low cut-off to what they need (I call these batteries "dumb" because they have a bms - it just does not interact with the inverter like the pylontechs etc). On the Axpert you should be able to set a user defined battery that meet these requirements. Lithiums do not need equalise (CV setting to 0min?). Since you will not have complex bms interaction make sure to set the maximum charge current to within spec for the battery. One issue might be to accurately determine/display state of charge/discharge? (no idea how the axperts determine state of charge/discharge but voltage alone is fairly useless for this on lithiums). Your choices for 24V lithium are a bit more limited (locally I can think of pylontech and then the freedomwons and bluenovas). Sticking 2 "dumb" types in series will probably be taking more money out of your pocket than one of the fancier pre-built 24V types, unless you go the second life battery route. DIY is also an option. I have no idea how well the pylontechs/BYD/Shoto/Narada etc batteries function without the comms cable and also do not know if the 12/24V axperts have any comms capability. If potentially looking at lithium type money to replace batteries I think I would do some serious calculations (of the accounting type) looking at potentially upgrading to 48V. Don't know how it will impact your solar though..

Thought with what seems like low solar yield maybe it is MPPT self-consumption (no idea if the MPPTs will actually show "own" self-consumption and it seems too high. Self consumption for the 75/15 is indicated as 10mA-15mA for 24V). More likely indicates consumption of load connected to the load output (MPPT <=100/20 = load output)

as pointed out by @Jaco de Jongh more details about the issues might better help members to provide opinions and maybe even solutions. I think many vague generalisations confound the matter a bit - I see the following At the very least there are many different makes of lithium batteries and from different makers there are different models. Some lithium batteries will work easier with some inverters/chargers than others. Some lithium batteries can seem a bit "fiffely" to set up. If a lithium battery BMS repeatedly disconnects the battery because some setting on the inverter is incorrect or the comms cable is plugged in the wrong port this can seem like a "battery issue" while it is actually an installer/user issue. So, what is meant with "issues"? (Never been able to switch on the battery... battery keeps on switching off at some time during the day/night.... battery when fully charged only lasts 10 minutes but 3 months ago it lasted 8 hours and 6 months ago it lasted 12hours.. etc)? This is probably most relevant for you - does Northern Cape/Namibia type WARM temperatures break lithium batteries? In terms of total lifespan of the batteries it probably can but those same temperatures will likely do the same to lead-acids. All battery (including lithium) specifications are generally rated at a temperature of 25 degrees C and when going outside of this temperature the performance will differ. For lead acids there is a basic rule of thumb that for every 10 degree increase in average temperature the expected lifetime for the battery is reduced by 50%. (if the battery was designed with an expected life of 10 years and it is operated at an average tempertaure of 35 degrees you will likely only see 5 years from the batteries if you are lucky) From a VRLA manual Lithiums like any battery are not immune to heat. In one experimental study lithium cells stored fully charged (not best practice) at 35 degrees showed minimal capacity loss even after almost 2 years (still mainatianed about 90% of their starting capacity) but cells stored (again fully charged) at 60 degrees barely made it to 4 months (maintained only about 10% capacity). The day-to-day use of the batteries is also influenced by temperature. Temperature compensation during charging being especially relevant for lead-acids. If this is not done the battery lifetime will be reduced. Many lithium batteries will indicate different temperature specs for charging vs discharging - charging having a lower max temperature (generally around 45 degrees C) than discharging (50-60). The lithium battery BMS might temporarily disconnect the battery during charging if the temperature is too high - while inconvenient at times it is not a sign of a malfunction - it prolongs the battery life. With that in mind it is probably safe to say average temperatures above 40 degrees C will cause premature loss of capacity in any battery. (i.e. don't put any batteries in an unventilated corrugated shed in the full sun during the summer in vioolsdrif). So, If we assume "issue" means the battery will not switch on, how do they know the heat caused the issues and not the 80km trip over a corrugated dirt road that shook lose some solder joints on the batteries (and the bakkie's bulbar...). If the battery capacity is prematurely low, is this because of heat or were the charging parameters perhaps incorrectly setup (maybe same parameters used as for lead acid?). Were these some once-of no name imports or batteries from a fairly reputable manufacturer ? They definitely are but at the same time some installers/users that are used to one thing sometimes struggle to use/accept newer/different technology. (someone referring to lithium batteries as Star Trek batteries sometimes being a clue). While not impossible I would be curious how many of these 15 year sites there are compared to the number of 3-5 year sites. Lead acids could very well be the more appropriate solution for you but that will likely be determined by more than just whether it is warm where you ive.

the fan is worth a try and a much easier "retrofit" than this (actually forgot (some) houses have these) ..

Even a little USB desk fan seems to make a difference to circulate the warm air better. Have not tried the thermoelectric ones but like the idea. Not being able to manually control the speed could be bit of a gamble if the fan air displacement is not matched well to the room size/volume etc? Other than a sledge hammer, I would not mind an easy solution to get rid of the wall space between a ceiling and a door way (probably has a special name?)... that space creates an upside down dam wall that prevents the warmer air from circulating to more of the house. Maybe my PIR is special 🙂 (It has no problem with a gas heater). In my case the PIR is positioned behind and to the side of the stove which gives it a slightly side-on and looking away from the stove perspective. My theory is that, with the stove producing very noticeable convection of warm air rising and suction of cooler air from a passage area, which both the stove and PIR partially face, quite pronounced thermal turbulence is created that is "seen" by the PIR as a moving heat source.

btw @Energy some things I neglected to mention - these stoves take a bit of time before they are at "running temperature" and if atmospheric conditions are less than ideal (ambient temperature not that cold and perhaps some wind added) they require a bit more tending to to get/keep going nicely - but when they are going they are fantastic. something else that none of the overseas forums/info/manual/spec sheets mention is that if you have an alarm system with PIR's in the vicinity of the stove the PIR will attempt to emulate a strobe light at a rave (people still do that?) onoffonoffonoffonoff...so if the stove is going and you need to pop-out to go buy a mask or bread or head off to bed with the alarm set you may need to bypass the PIR...

Thank you for the photo @JohanG . Must say, if that is the standard of their materials/quality control I would be left to wonder what else they got wrong and rather replace the lights as soon as feasible

Buy a donkey.... for undoing my attempt to get this fred back on course ... 🤐 for the foreign participants (listen to source..and read translation)

by the way, @JohanG, after I have thoroughly derailed your thread and now trying to get back to some of your questions I will say the following If it is a concern, I doubt that the lights going brown is a sign of something wrong with your inverter/battery or how you use it. Quite likely the material used for the lens part had some quality control issues and the material therefore starts to discolour quickly. If you can comfortably hold your hand against the lamp when it has been on for quite a while the brown colour is probably not directly from heat/scorching.... if they get so hot that you find the heat uncomfortable it is probably safer to replace them with something else. I posted some info in an earlier post (here) that could help you find some reasonably priced replacements (including some OSRAMS as @Youda referred to) but there are many alternative sources.

for some strange reason at the moment a hazmat suit is probaly somewhat harder to find.... but then again until a week or so ago, here a bit south of the tropic of Capricorn, trying to buy pyjamas could just maybe have landed you in jail ...😉

Welcome 🙂... but... as that statement reads it could also get you referred to the following for assistance Vodacom 082 241 9952 MTN Fraud Line – Call 083 123 7867 Bidvest Protea Coin Hotline – Call 086 101 1721 Telkom 0800 124 000 Cell C 084 135 SAPS 10111 Or e-mail have a look through here for context... 🤔

Often the good ones have both....and the ones without one also end up without the other... 😉 🙂

...but will you achieve the same with hair from a hare? 🤔 😜 I updated my forum signature accordingly but unfortunately can't get it to display BEFORE my post content so readers with a keen eye or those well versed in brits will have to bear..bare ... continue working on their patients...