martinmcg

Has anyone worked out setting 60 on Output 2? Every time I set it, it gets set back to 10% presumably by the BMS - which makes it totally useless for my intended purpose of cutting power to non-essential loads when the battery gets to around ~30%. Am off grid and want to avoid a situation where I use the oven after a few overcast days in a row and suddenly lose the fridge, internet and lights. Any way to get around this glitch?

For the record, the resolution to this problem was a firmware update from Segen Solar. Rather frustrating waste of time. Thank you all for your help. I (foolishly) assumed that on checking their firmware upgrade site was out of action that they would at least be shipping new inverters up to date or close to. As a btw: When we tried the solar panel test, not sure what went wrong but when we flipped the fuse off it failed/caught fire.

Thank you both for your help. MultiSIB doesn't seem to output this, and Watchpower has PV charging current but for some reason you can't get it in the data log. Do you want the PV current (ie at PV voltage) or PV charging current (at battery voltage)? I can derive the PV voltage from the graph or tomorrow I will record it off the inverter screen. Else can record the PV charging current off Watchpower. Not a typo unfortunately, really odd. May have another multimeter I can access at the neighbours, I'll try find. Any further tests you'd suggest I run to isolate the source of the problem?

I had been battling away trying to get the Watchpower wifi to work and having no luck, thinking I didn't have any of the right cables to connect to my PC, but fortunately my powerbank charging cable has just the right one and I've managed to connect it now. Here you can see the PV watt and volts in the on/off phase, then as soon as we cover/uncover half the panel it evens out. I'm surprised, the multimeter still shows fluctuations but seems good at the inverter. Not sure if relevant, but with the circuit breaker off, the VoC is steady at 183V on the panel side, but it fluctuates on the inverter side of the circuit 20-40V. The voltage fluctuations during the "fault" stage are also less severe than seen on the multimeter. So I can't give you a day yet, and this laptop does need to be used at times unfortunately so constant monitoring is not possible. But I can show you any of the behaviours. Will do the panel test later today or tomorrow. Edit: the battery amps are also interesting: they match what the inverter shows, but the battery's display clearly shows it going to zero (or negative where there is output)- which I do trust more.

Thanks Talia, yes CBs are DC rated and 20A rated. Unfortunately a fifth panel will be a month away (we are in a remote location) when we return, but see my explanation above indicates a start-up issue but doesn’t seem to be voltage related.

So I have done some further tests that may offer some clues to the puzzle. I found out that it does startup (rather than on/off) when the power is less than 600W. So I emulated that the next day by covering half a panel, it started up, then immediately uncovering and it kept working, going up to 1500W and staying working the whole (clear sky) day. I left it on overnight and it kept working with the sunrise etc. At around 9:30am though, roughly 700W, it stopped working (fault on/off on/off) but this did coincide with the sun passing through the first clouds we’ve encountered. To me this pointed to the startup voltage issue Coulomb pointed out, but, if I cover entirely one panel and keep it covered (lower VoC), it starts up and works. If I cover two panels, it doesn’t start up at all. But four panels, the highest voltage, it has the on/off on/off fault. The higher the peak wattage, the longer it stays on for, so at peak of the day it’ll be 2.5 seconds on, 0.5s off. Later it’ll be 1s on, 0.5s off. So it gets to peak watt before shutting off. Something else is that with the multimeter on the PV input, even when the system is working 100% fine for hours and charging up the battery at 25A, the voltage is still fluctuating 40V-180V every second or so, is this not normal? I also inspected and worked around with all the MC4s and didn’t notice any issues. Thank you for all your help!

Thank you Talia. I’m not able to do this test until in the week as don’t have an isolator, rather a set of two circuit breakers, not sure why but that was the guide we were following. Or can it be done with circuit breakers? One thing I don’t fully follow is “bridge the top and bottom contacts” - by this do you mean run a piece of PV wire between them? What is the role of the isolator then, is it not being short circuited? Sorry if a dumb question ☺️.

Thanks Talia, Chris. Haven’t yet had a chance to inspect earth & MC4, but have taken a multimeter to the breaker to check voltage. It is constant around 178V, and then when breaker is switched on (supplying inverter) the voltage is varying massively and quickly, 50V-185V (which does tally with what I saw on the inverter, but I figured that was downstream of the charge controller). Once switched off, goes back to constant (up/down 0.1V at most). In my mind this suggests 2 or 3 rather than a faulty charge controller, but I know electricity is more complex than that. Might this be indicative of where the problem may lie or definitely does not lie? Thank you all for your help.

Hi all I’ve scoured forums and unable to find something similar, wonder if someone might be able to shed some insight. I’ve had and been successfully using a Kodak OG-Plus 6.2kw with a Magneto 48V 200ah battery connected to the grid. We have now moved it the offgrid location where it continued to work fine while we mounted the panels. BMS working smoothly. Panels switched on (4x JA 460W), and they’re getting the wattage and voltage I’d expect (183V and 800W+ in late afternoon). It’s a completely clear day, and battery is at 40%. However, PV input is switching on and off about every second. I can hear the inverter winding up and down, and see on the battery display it oscillated between +A and -A and the charging light flickers, pauses, flickers, pauses. On the inverter I don’t see the wattage go down to zero, goes from 800w to about 250W (and fluctuates between) and voltage fluctates 167-183V. But judging from the sound and the battery, it is going to 0W (there is only ~100W load) maybe for half a second and then bouncing back. I’ve only dared leave it on for 10 minutes to see if problem resolves, which it did not. What might be the culprit here? As simple as a loose connection or something more problematic? Help would be greatly appreciated. Unfortunately I haven’t gotten Watchpower working on my devices, so unable to show you a graph right now.

Thanks Scorp007, much appreciated. One further question, the max PV array figure quoted, is that a hard limit or just a guide based on the max Voc, Isc and 120A hard limit? eg. I believe with the Voc (500, operating 450) and amp (27A) limit of the Kodak OGPlus6.2kw I could wire 2 strings of 8 panels, JA Solar 460W (Voc 50.01, Isc 11.49) which would be up to 7360W, exceeding the 7000W on the inverter datasheet. Would this power just be clipped / do damage or is it usable based on the Voc (400.08) being below 1.2 safety margin and amp<27? Thanks.

Hey folks Solar newbie here. Looking at some Kodak inverters and have a few questions if you might be able to assist: 1) Kodak OG7.2: koda-Axpert Max-20210601 (shopify.com) The max PV array is quoted at 8kw, but the maximum solar charge current is 80A, so that works out at about 4kw. I get that an 8kw array would rarely be producing 100%, but this seems like a significant waste of power. Am I misunderstanding the spec sheet, is it 80A per MPPT? 2) Also looking at the Kodak OG Plus-6.2: KODAK-Axpert King II TWIN (shopify.com) and what I don't understand is the Voltronic TWIN series is advertised as having a 60VDC PV input minimum, the OG+6.2 has 120VDC. What would happen if I only connected two panels* 70VDC in total to it - would it not run, or just be a bit inefficient? (*my use case is: want to set up power for an off-grid site ahead of building commencing, so want to go low on battery + panels for now to save cashflow but will eventually expand to about 6-7kw of panels). 3) When it comes to "remote monitoring" via Wifi, if I leave my house with the power on and internet connected, am I able to get any detail on the inverter status on my phone/laptop, or ideally set up some sort of alerting system? Or is it "remote" as in "within range of the wifi of the inverter"? I'm concerned about fire risk (but also losing everything in the fridge/freezer) so would be ideal to get an early warning if I'm away for a couple weeks, so that I could send a neighbour to inspect. Thanks for the help!