Chris Hobson

Just one question how did you extend the battery cables between the two battery cabinets? I am possibly getting one more Pylontech and my current cabinet is full.

Beautiful setup - just a word of warning those Goodwe ES inverters should not be run on a generator. One use to have to read the manual carefully but I see it has changed and explicitly states no generators. This information was previously hidden in the troubleshooting section

Thank-you Lindsay. I have written my own crc function to take into account the Axpert's idiosyncrasies and have fewer dependencies. After spending some time fiddling with Node Red and node.js I have developed an aversion of libraries and dependencies unless they are well written and documented. It appears Voltronic use a chipset that masquerades as a Cypress Semiconductor chip. From a little saunter on the web Cypress seem to disown VID 0665 PID 5161 which leaves most of us fumbling in the dark. The Python 2/3 changes how strings are handled does not help either. I prefer how Python3 handles strings with text and bytes being discrete but does give one a headache when you trying to get an officially undocumented chipset to work. Thank-you Lindsay for rolling several large boulders out my way. In the mean time I have dusted off my 30 year old programming skills. I hear a cacophony of laughter coming down the ether. I cut my teeth on Basic, Cobol and eventually a little bit of Pascal and DOS doesn't stand for Dark Outer Space. Since I am so rusty I usually write 2 lines of comments for every line of code. I cannot abide not understanding code I have written/copied and end up dissecting github code. This I suppose defeats the object of repositories but too many folk (myself included) borrow code from a different source with scant regard to its robustness. This is in no way a slight on Lindsay's contribution for which I am most grateful.

About 4 years ago I installed an electric geyser to act as a dumpload. When my family is away I can get away without using gas. Hot water from geyser powered by PV and I use an electrical kettle in conjunction with a thermos, and cook on an induction plate. Now during lockdown I have my broom-flying mother-in-law to stay and in the interests of my own sanity have abandoned any ideas of trying to be frugal in our gas usage.

Timeous - I am trying to do much the same. Thank-you Gnome and Lindsay

Noark make a nice relatively inexpensive DC breaker . Note when wiring up a DC breaker - most are polarised and wiring it up incorrectly is akin to using a AC breaker. The catch cage is on the wrong side and the magnetic field send the arc in the opposite direction. Look here.

The BMV posts 33 different data fields (including 2 check sums) every second. I have isolated the useful data and restricted it to every 30 seconds. The switch was not behaving as I would expect and I had to order the data fields and change how to switch evaluated the data to work as it should. For instance BMV and VS needed to be evaluated before V and H10 to H18 needed to be evaluated before H1 to H9 (in spite of a setting set to check all rules first) . Now to conquer the Axpert. @ChristoSnake I have imported OpenWeatherMap data but it seems to be you can either get hourly weather forecast or a 5 day forecast neither seem particularly useful to me. Is there a forecast for 24 hours?

I am pulling all my data via Emoncms. All data posted every 30secs, except Grid Watts which is posted every second. I need to know if the generator is on to prevent the staff houses unnecessarily being powered by the inverters. They can receive power directly from the generator not via the inverters. Trying get inverter data caused Node Red to bomb this evening. I will crack this somehow I am determined.

Hi @ChristoSnake Wow you have inspired me to take mine further. How are you getting inverter data into Node-Red? I can get BMV data into Node-Red but have yet to work out how to use the barrage of data effectively (it posts every second). I have unsuccessfully tried to get inverter data into Node-Red directly. I have noticed data that cannot be correct and want to filter data coming from my inverter.

I looked at this a couple of months back, mainly to see how Pylontechs were performing. I did not notice that BYD had dropped from its perch.

I use a 20A 1P DIN rail contactor that I imported from China (ages ago) in conjunction with Sonoff switches. Sonoff switches contactor - contactor switches pump, geyser etc. Contactor were bit noisy to begin with but now are quiet. Even though a Sonoff is rated at 16A you can see that the terminals are not designed for that sort of load. Unless you already have a relay I would go with a contactor they are a bit more robust and if you get a normal 3P contactor you can switch both live and neutral which I like.

Hi Kiranbhowan You need a DC contactor or a DC change over switch - both of which are more expensive than their AC counterparts. There is usually a magnet which deflects the ensuing spark when switched into a catch cage. ABB make a DC rated contactor. If you cannot get a DC contactor you can make a very good snuffing circuit by placing a large enough capacitor across the terminals of the contactor. While the contactor is closed the potential difference across the terminals is zero. As the contactor opens there is a potential difference and the capacitor starts charging. I am not sure your local authority would accept a contactor/capacitor combination. Your capacitor needs to have a voltage rating higher than your PV strings. There are some good videos on Youtube. Here is one. I cannot find the one I was looking for. This pommie's demonstration is good but health and safety would have a field day

Thanks @ibiza. Now that I am grounded I have a bit more time