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Thank you for the great forum, Safe Driving over the weekend. Sincerely Jason

PeterDawson

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  1. Yes, the tail charge is taking a little longer with a slower ramp down, but not a problem. Ill keep lowering the voltages and see where we end up. Thanks for replying. Cheers.
  2. Hi Coulomb Thanks for still thinking about us. Zooming in more around the trip: Here is a recent trip which occurred while the charger would definitely been in Bulk mode. This one seems to have been caused by a decent load turning on and off. My parents are at the house and my guess is that this is the microwave. As always, I bump the bulk charge voltage setting (prog 26) to kick start the SCC again. I have been steadily reducing the charge and float voltage which seems to have minimised the trips to maybe once or twice per week. My parents have been in residence for five weeks now so there is more usage on the system than normal. Current settings: Prog 26 - Bullk charge voltage: 51.3V Prog 27 - Float charge voltage: 50.6V These are significantly lower than the settings suggested by the battery docs of 53.5V and 52.0V, but they're working for me. Do you see any issue with running such low voltages? Thanks as always.
  3. Thanks for the feedback Albert. Glad you are making headway. Would be very keen to hear how your system is doing in a few more days. Thanks Peter
  4. HI All. Thanks to all the contributors to this. Here is the detail on my inverter. I cant read anything into it, but if its useful to you then here it is: Mine was installed in Oct 2018. Not sure of the manufacture date unfortunately. Lowering the charge and float voltage settings as discussed early on in this thread seem to have reduced the occurrences of freezing, but not resolved it. Rgds Peter
  5. Sure sounds like the same issue. Would you potentially be able to carry out this test above? Maybe change the bulk charge voltage when the inverter is running fine and confirm that there are two clicks. Off and then on again. Then the next time that the system freezes and PV watts drops to zero, change the bulk charge voltage by 0.1 and listen for how many clicks you here. My suspicion is that there may only be one click, the on click, since the SCC is already off. Thanks in advance.
  6. Thanks for all the feedabck guys. What about linking them to this thread for added pressure?
  7. Hi Jaco. I bought it from a supplier in Middelburg. He's been great so far. We've exchanged a few ideas on the issue for a few months now, trying various setting changes, but nothing has helped. I've sent this thread to him to follow and depending on what we learn here he'll take it up with his supplier. I guess this is what makes the extra cost of the Victrons worth it
  8. The 07:00 to 09:30 is when the SCC was in its "tripped" state. The 11:00 to sunset is as you suggest, full battery and solar is merely running the fridge and the float of the battery. Here is another example of the SCC "tripping". It went down at about 11:33 when the washing machine element switched off. Fig 2. It then stays down until I noticed at 14:30ish and got it going again. Notice that I ran the generator to charge the battery up from 16:00 to 18:00ish. Fig 1. Whole day with relatively heavy system use. Fig 2. Showing trip as washing machine element turns off.
  9. Thanks for the replies Jaco and Chris (I hope I got that right). you're quite right here. I cant say that I have ever been standing next to the unit when its stopped charging, so have not heard whether there is a click from a relay. That said, you've given me an idea. I'm not exactly sure how the charger works, but I know when I change the bulk charge voltage parameter, there is some clicking from relays, possibly the charger unit switching off, parameter change takes place and then the unit starts again. Does this sound like normal behaviour? If this is the case, there should be two relay clicks, off, and then on again. So the next time that this happens, and when I use the bulk charge parameter to bump things back to life, I'll listen to hear if there are two clicks or just the one on click. Here is the trend of the PV voltage and current during one of these trips. Cheers Peter
  10. Hi All This is my first post, but I've been a long time lurker, so first off, thanks to the creators of PowerForum and to all the contributors for making this a truly great information resource. Background: In Oct last year I installed a small off-grid system in the SA bush. Axpert MKS 5kVA. 9 x 260W panels (3x3). 1 x Huawei ESM-48100 battery (48V, 100Ah, 4.8kWh). Generator connected to AC in, but only used to charge batteries very infrequently. ICC with BMS-702 used for monitoring and remote setting adjustments. 90% of the time the house is vacant and only the fridge draws power from the system. For the most part the system has worked very well. There are however some strange behaviours from the Axpert (and I suspect the MPPT) that I have not been able to iron out. The first of these strange behavious is illustrated in Fig 1 below showing the charge period of the battery in the morning. The SolarWatts (blue pen) shows the fridge's compressor periodically switching on and off. Batterywatts (orange/yellow pen) shows the power flowing either into or out of the battery. Notice how the pvwatts (green pen) sometimes drops right off when the fridge starts up. This behaviour is not consistent as can be seen at 08:15ish. Any ideas? Fig 1. PV power drops to zero when fridge compressor switches on. The second, and more annoying behaviour is illustrated in Fig 2 below. Sometimes, the MPPT seems to shut down and the inverter switches to battery mode. The panel voltage jumps to Voc (103V for panel Voc of 36V), and the current drops to zero. The trend in Fig 2 shows this happening at the same time the fridge compressor switches on. This is also not consistent. Fig 3 shows it happening when the fridge compressor switches off. It does however seem to always be associated to a change in inverter load, but the size of the load does not seem to matter. Its not worse when the draw is higher, say when the dishwasher element or the kettle switch on or off. Sometimes things resort to normal in a few minutes or hours, but typically only the next morning when the sun comes up. If I happen to notice that the MPPT is not drawing any power from the panels, I can log onto the RPI remotely and bump the Bulk Charge Voltage setting by .1 and that kick starts the MPPT again. This behaviour does not seem to correlate with battery SOC nor with the panel output. Sometimes we can go for weeks without it happening. Today it has happened twice, once early this morning when panel power was 175W (Fig 3 @06:57), and then again just after I bumped it back to life with panel power output at 1,300W (Fig 4 @09:37). Fig 2. MPPT seems to switch off completely and inverter switches to battery mode when fridge compressor switches on. Fig 3. MPPT seems to switch off completely and inverter switches to battery mode when fridge compressor switches off. Fig 4. MPPT seems to switch off completely and inverter switches to battery mode when fridge compressor switches on and panel power at 1,300W. I'd be very grateful for any ideas or advice on solving this. Thanks Peter

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