JohnDM

I have two Kodak OG Plus 5.48 inverters running in parallel, Hubble batteries, no Eskom connection, solar panels. They've been running well since December, no problems at all, EXCEPT for the same intermittent popping/clicking sound, described and recorded by Pieter above, from EACH of them at random and infrequent intervals, daytime and nightime. I see, above, that others have had this "problem" - did Kodak ever get to the bottom of it?

The system above (two Kodak Kings, connected in parallel, twin AM2 batteries, no Eskom connection) has been working perfectly since January. But I'm hoping someone can help with a fresh question: If I want to use a generator to top up the batteries on a cloudy day, must the generator be connected to both inverters, or is is sufficient to connect it to just one? Thanks......

Update on the above, in case someone else follows this: The system doesn't work with only one inverter providing load. It seems ok at low loads, but as soon as the load increases, it gives an E72.

Good news!! everything connected, inverters in parallel mode, working fine! Only one is providing load for now, but that, too, is working perfectly. Thank you to @Steve87, @TaliaB, @Calvin. Your help is hugely appreciated. Got me through a somewhat nerve-wracking patch!

Thanks @Calvin. I want both inverters running, ideally in parallel mode, because they each have to manage part of the PV array and charge the batteries. My biggest fear is "burning and blowing stuff up". I've installed individual neutral and live breakers, so that I can leave the "neutrals" connected but only one "live". I'm going to do the synchronisation this morning, and I'll report back here on it it goes. I don't know if running the inverters in parallel has any effect on the inverters' management of the battery charging process. I'm going parallel in case it does. There's little to no documentation on this. The Hubble support desk says to run in parallel, but no reason is given, and @Steve87 advised that "DC coupling" independent inverters should work. My ultimate fallback will be to reply on the Hubble BMS, which seems to be very good. I must say, this is an excellent forum. Plenty of very useful advice. Thank you to all. I hope this thread might prove useful to others.

I decided to ask Bard this question, and here is the reply. I'd be keen to know if it's correct: Yes, if you have two Kodak King inverters properly connected in parallel with their neutral outputs linked, closing the live breaker for the load on only one of the inverters will provide usable power to the load. Here's a breakdown of how it works: Parallel Configuration: In parallel mode, the inverters synchronize their output voltage and frequency, creating a unified power source. They share the load, effectively doubling the available power capacity. Neutral Connection: Linking the neutral outputs ensures a common reference point for the AC voltage, crucial for proper operation and safety. Load Isolation: While the inverters are connected in parallel, each has its own live breaker for load isolation. Closing only one breaker routes power from that specific inverter to the load, while the other inverter remains in standby mode.

@Steve87, @TaliaB, thank you both for your invaluable input. Please may I ask one more question: When I go through the steps above: connect load "neutrals" , leave load "lives" open, configure both inverters to parallel, switch off, and switch everything on again: If I then switch on the live breaker for only one inverter, instead of both, will that inverter still deliver power to the load? In other words, the two inverters are connected in parallel, and synchronised, but only one is providing power to the load. It seems to me that this might reduce the risk of "burning and blowing stuff up" (as per Steve), especially as I don't need the second inverter for load. I know I should ideally be using both, but I'm not an electrician, and I'm seriously worried about burning and blowing stuff up. If I can get it all working like that, then I'll call in a qualified person, and get him/her to check everything I've done and hopefully issue a CoC. And at the same time, activate the load for the second inverter under his/her supervision. Thank you again for all your help.

Thanks, Steve. That makes perfect sense, and you've put my mind at ease about parallel operations. So assuming I opt for a parallel setup, I have one more concern, which I'm hoping you might be able to help with: On very cloudy days, I run a generator if the batteries need topping up. In the past, this was connected to the "Utility input" on the single inverter. So, under the new arrangement, should I connect the generator to one, or both, of the inverters? And will it present a synchronisation problem if I start it up? Or would it be better to shut down the second inverter and revert to single mode, before starting the generator? I really appreciate your help with all these questions. I've done my best to research these points using the manuals provided, but as someone said elsewhere on this forum, the documentation available is notable for its paucity, and I'm by no means an expert on things electrical.

Thank you, Steve. In explanation, I'm off grid, no utility power, and I bought the second inverter when the first when in for repair... the "qualified installer" popped the MPPT due to too many amps from the newly-configured PV array. So now that I have it, I may as well use it to split the PV array and charge the batteries, and act as a back-up unit. I don't need it for load. I read the Kodak manual, which contains lots of pidgin English, and it implies that commissioning parallel operations requires utility power - I'm not sure why, but not an option. So I'm looking for the least risky way out, and I can't afford any more blown equipment. The Kodak has no inverter-battery comms with Hubble, so I rely on voltages, but the Hubble BMS seems very good, and it restricts charging amps all by itself as it fills up. Thank you for the input, it's much appreciated.

I would appreciate any help on this: I have two Kodak OG-Plus 5.48, and two Hubble AM2 batteries connected in parallel. My domestic load is less than 5kw, so only one inverter is needed for the load. I am about to attempt to switch the inverters on in parallel mode, but I would much rather leave the load on one inverter only, and use the other inverter simply to deal with half of the PV input, and to have both inverters charging the Hubble batteries. Is it possible to do this, i.e. use a common battery bank but not in parallel operation?

Since you mention your reluctance to parallel, I would appreciate your input: I have two Kodak OG-Plus 5.48, and two Hubble AM2 batteries. My domestic load is less than 5kw. I am about to attempt to switch the inverters on in parallel mode, but I would much prefer to leave the load on one inverter only, and use the other inverter simply to deal with half of the PV input, and to have both inverters charging the batteries. Is it possible to do this?

Coulomb, Versions are: U1=72.02, U2 = 02.83. To the credit of Sengen, they have been in contact with me to try to address the issue. The downside is that they want the inverter for some weeks to diagnose. Not an option for me, as I'm off grid. I will post whatever solution is found.

Sam79, I've been monitoring my Kodak King with WatchPower. It always shows that PV wattage is up to 25% less than Active wattage, and even goes so far as to show a drain (amps) from the batteries. And yet the battery voltage increases, i.e. the batteries are actually charging... I'm guessing that the firmware in the Kodak is rubbish... to prove it further, I plugged in a different Axpert-based inverter, and got the expected PV readings.

Would anyone be able to tell me why my new King inverter seems to under-read the power being sent from the PV array? Right now, I have 3300watts of solar panels connected. It's a bright sunny day. The readings are: PV Voltage 73.2V PV Charging current 27.6A PV Input power 1410W Output active power 388W Charging current 19A. I would expect the power from the PV array to show as being around 2200w on a day like today. My calculation shows 73.2 * 27.6 = 2020W. (My old Axpert gave much higher readings than this.) What am I not understanding? Many thanks for any help. John.

This is the answer from ChatGPT: Axpert is a brand of inverters commonly used in off-grid and hybrid solar power systems. When you mention "battery cut-off voltage" in the context of an Axpert inverter, you are likely referring to a feature called "low voltage disconnect" or "LVD." The low voltage disconnect (LVD) is a critical safety feature in solar power systems that use batteries. It is designed to protect the batteries from over-discharge, which can lead to permanent damage and reduced battery lifespan. Here's what typically happens when the Axpert inverter reaches the battery cut-off voltage: Voltage Threshold: The Axpert inverter is programmed with a specific voltage threshold (battery cut-off voltage), which is typically set slightly above the minimum safe voltage for the connected batteries. This threshold is often user-configurable. Monitoring: As the batteries discharge during normal operation, the Axpert inverter continuously monitors the battery voltage. Voltage Drop: When the battery voltage drops to or below the pre-set cut-off voltage, the inverter takes action. Load Disconnect: The inverter will disconnect or cut off power to the connected loads (appliances, devices, etc.). This is done to prevent further discharge of the batteries, which could damage them. Alarm/Notification: Some Axpert inverters may provide an audible or visual alarm when the low voltage disconnect is triggered. This serves as a warning to the user that the system is running on battery power and that action may be needed. Reconnection: Once the batteries have been protected and the voltage rises back above the cut-off threshold (typically due to solar panel charging or other power sources), the inverter will automatically reconnect power to the loads. This feature is essential for preventing deep discharge of batteries, which can shorten their lifespan and render them unusable. It ensures that there is always a reserve of charge in the batteries to provide backup power when needed. Keep in mind that the specific operation and settings of an Axpert inverter may vary depending on the model and manufacturer, so it's important to consult the user manual or documentation provided with your particular inverter for precise details on how the low voltage disconnect function operates and how it can be configured to suit your needs.