superdiy

I saw this 12V Microwave oven on Takealot today - 55A @ 12V, about half of that @ 24V - poor battery! Heat up the pie and the battery is dead.

The same screws also pull the aluminium pc board towards the heatsink and if the plastic at the back fails, the crews are in actual fact not applying pressure to keep the pc board in good contact with the heatsink and that might result in less heat transferred from the pc board to the heatsink, which will cause the LEDs to overheat and fail prematurely.

I've sent it via PM.

Unfortunately that painter will not do it exactly the way I want it done. He will spill paint somewhere, even if it is little droplets and he will paint something he shouldn't have - you get the picture. If I do it myself and I make a mess or spill a few drops of paint I can only blame myself, but in the end the job is done the way I wanted it done. I will ONLY get someone to do a job at my place which I really cannot do myself, e.g. where you require specialized tools and it simply does not make sense to buy those tools for a once-off installation - here I refer to something like the installation of an air-con where you have to have at lease a tube expander / reamer tool set and a vacuum pump, which will set you back a few grand. I also like working with my hands and doing things which are way different from my day job - but that is only me and I know some people have 10 thumbs when it comes to working with their hands.

In layman's terms the relay on the BMV is like a stock standard on-off switch, similar to the light switch mounted on the wall in your house. The purpose of a switch is to either complete a circuit in order to make the current flow through the circuit or to break the circuit to stop any current from flowing in the circuit. The contacts on the BMV does exactly that. You can connect it in a circuit to switch something on or off depending on the action assigned to the relay e.g. switch on at a certain SOC. The two terminals are not polarity sensitive, e.g. positive and negative and they are potential free - they do not output a voltage. I am not familiar with the wireless module you are referring to, but what I can determine from the extract above is that you can control it's outputs by varying the voltage between 0 and 10V on each input - PWM outputs mean that by varying the voltage between 0 and 10V on the input, you will have a varying output - almost like a dimmer effect. You can connect the module's input(s) to and external power source of 10V (less than 10V will result in a not full on at the output, because the output is PWM controlled) (more than 10V might damage the module) and connect the BMV's relay contacts in series with this voltage applied to the input(s) of the module. The BMV's relay will then either apply the external power source' voltage (10V) to the module or not, depending on the programming and state of the contacts (open or closed) and thus control the output(s) of the module between full off and full on (if the input voltage is equal to 10V). Keep in mind that the BMV's relay contacts are rated at 1A 60V DC - that is perfectly fine when you are going to use it for the module's input(s), but if you are going to try to switch your geyser element with the BMV, you will fry the relay's contacts - it is however possible to add another relay etc. to the circuit to achieve that, but I'm not going into detail about that now.

You are confusing me now when you say: "so zero goes into / out of batteries as per BMV, yet the batts are not damaged." Read your statement again... Zero goes into / out of the batteries, yet the batteries are NOT damaged

Nothing, the inverter will draw only what it needs from the panels.

Chris, you are spot on, electricity is drawn, not pushed. As long as you stay below the maximum input voltage you should be safe. The inverter will only draw what is required. As you've mentioned, you have had first hand experience where your panels produced 3300W and your inverter is still running today.

That's another interesting google tool. I looked at the demo image though, but they have missed a few roofs and some of them display strange "solar" patterns - maybe a few teething problems, but I like the idea.

I love this. Must say we don't only have Samsung appliances as the little one said, but most of them are... AEG electric hob & oven, Defy gas hob, AEG dishwasher, Bosch refrigerator, Defy chest freezer etc. etc. etc. Guys, it is time to update your signatures.

Just the other day one of my kids made a comment about everything in our house being Samsung and then I thought about it... 4 x air-cons, 3 x tablets, 2 x phones, 4 x flat panel TVs, 1 x DVD player, 2 x computer monitors, 1 x washing machine - all Samsung. Must say I've had better luck than you with my phone; S3 mini more than 3 years old, still on its original battery, still lasting for about 5 days on a charge - touch wood.

A comment like that was expected.

Agreed, not bad at all!

http://www.sinetech.co.za/news-omnipower-powerbank-affordable-lithium-ion-battery-energy-storage.shtml The PowerBank is a high power and compact 48 V, 6.5 kWh energy storage solution capable of being discharged to 80% for approximately 5000 discharge cycles. The PowerBank can easily handle 6.5kW continuous power draw as well as a 10kW in rush capability whereas the “other” very well-marketed Li battery (at the time of article release: 6 May 2016) can only deliver 3.3kW of power. The Omnipower Lithium-Ion storage system is extremely cost effective even when compared to high-cycle lead-acid batteries; this is mainly due to The PowerBank’s longevity and high cycle life. In order to compare the costs of The PowerBank with that of lead-acid we compare the Rand per kilowatt hour (R/kWh) each technology can deliver, calculated by taking the cost and total kWh over the batteries’ life time into account. The life cycle cost of The PowerBank (±5000 cycles) is approximately R 1.85 / kWh compared to that of a high cycle lead-acid battery (±1500 cycles), which is approximately R 3.65 / kWh. From this it can be seen that The PowerBank comes in at almost half the life-cycle cost when compared to lead acid batteries.

Don't look at the amps the MPPT pushes into the batts - that is not panel amps - totally different. Lets take the right hand one as example - Panel amps is at 25.64V (153 / 25.64) => 5.97A - Battery amps is 11.29A but at only 12.69V - don't confuse the panel amps & the battery amps. If you compare the PV V at max power (25.64) it sits between the 800W/m2 (45°C) value of 24.4V and the 1000W/m2 value of 26.7V as per the datasheet. Panel amps at 5.97A is just below 6.1A. Both values look very much in line with what the datasheet suggests. Still cannot understand why it floored you - that is what is expected - if it was way off then you had to be worried.

I'm totally with you on this one, but only if you don't have any partial shading. I think someone mentioned partial shading at a certain time of day visible in the video clip (blocked at work), and that defeats the purpose. If you are planning on buying or constructing a tracker you have to ensure that you never get any partial shading on any panel, unless you are using something like micro-inverters, but that is a totally different topic for another day.

What I could not understand was your comment above: "What floors me, it is the 200w Tenesol Panel" Are you satisfied, performing better than expected or worse than expected? 91W not optimally aligned and 153W optimally aligned on probably not a 1000W/m2 irradiation day looks perfectly fine to me.

Are you looking at the charging amps and maybe confusing it with panel amps? Totally different thing. Left: 13.23V @ 6.54A => 86.52W (91W from the panel) - looks in order Right: 12.69V @11.29A => 143.26W (153W from panel) - again looks in order

Am I missing something here? The left hand box indicates that the panel is outputting 91W and the right hand box indicates that that panel is outputting 153W? Left hand panel is fixed and right hand panel optimally angled - depending on how much is required to charge the batts at that moment and what the optimum PV watts (MPPT) at that stage is, everything looks in order. (for 200Wp panels)

Quite a few household appliances work like that - certain stoves / ovens with built-in clocks / timers, certain microwave ovens as well as the good old bedside clock radio. When eskom struggles, the clocks run slow and everybody is late for work.

Yes, you are correct, the software limits the ranges. Another question is if the inverter would accept values outside the ranges - I have not tried that though.

I had a similar problem. Every now and again I noticed that the PV power dropped quite a lot for a few minutes at a time while the skies are clear and the sun shines bright. My only thought was that one of these huge birds in our area (I don't know what they are, but they are huge and so are their no.2's) camped out on a panel and caused partial shading - as you know partial shading / covering one cell has a huge impact when you have only 1 serial string of panels. It is quite easy to get on to the roof and usually whenever I noticed this behavior I would grab the ladder and go check the panels, but to my surprise I never spotted a bird, there was no partial shading and no no.2's covering enough of any of the cells to cause the drop in PV, so I always thought that it might have been a bird and it flew away before I got to the panels. Then about a month ago on the Sunday morning I walked through the garage again and noticed the same behavior - a drop in inverter fan speed usually indicates lower PV power. I grabbed the ladder again and again found nothing out of the ordinary on any of the panels, but this time when I got back to the inverter the PV was still low. I then switched on the PC and checked the settings and the logs and then spotted the "Grid frequency upper limit reached" warning and noticed that the grid frequency was at 50.2 Hz and the upper limit was set to 50.1 Hz. Needless to say, as soon as I've changed the upper limit to 50.3 Hz, the PV power shot up and the inverter started feeding to the grid again. The verdict - the lower overall grid load on the Sunday morning caused the grid frequency to rise which caused the inverter to stop feeding back.

Hi Hasan, welcome to the forum. I've sent you the password. Let us know if it worked.

Another -10 points for Victron!

Something else I've found while trying to get my cable to work... The Victron VE.Direct Protocol doc contains incorrect information about the pinouts on the BMV. The TX & RX pins are reversed. The correct sequence is exactly the same as for the Consumer in the table - I don't know if the Consumer pinouts is correct or if the Producer and Consumer should simply be switched around. The correct pinouts for the BMV is as follows: Pin 1 - GND Pin 2 - RX Pin 3 - TX Pin 4 - Power + Initially I though my PL2303HX cable's pinouts was incorrect, but because I'm connecting everything through the ISO7221 isolator with specific IN & OUT pins I realised that the RX & TX pins in the protocol doc is indeed reversed.