admiral

@plonkster - how much does the voltage have to drop for the charger to change into bulk / absorb? My batteries are not really cycled - they are only used in load shedding, so storage mode is really not a bad idea *if* we don't have a lot of load shedding. And, by the way, the charger does *not* wait 24 hours to go into storage mode - it was way quicker than that after a full bulk / absorb / float cycle. An hour or so.

I have a Multiplus II 48/3000/35-32 - it is used as a UPS for my house and has no solar etc. connected. The only way for it to charge the batteries is using the grid. I have storage mode enabled as the batteries does nothing for long times until there is a power failure. The battery state of charge started at 100 % , and the inverter was in storage mode. We then had a 2.5 hour power failure, and the battery state of charge went down to 91 % . The grid came online, and the Multiplus II just went back into storage mode. The problem with this is that the batteries are charging very slowly, and they will never charge back up to 100 % - the only way for that to happen is to restart the inverter. We've had a few power failures since the last one, and the battery state of charge went down to 83 % this morning - and still the inverter went back into storage mode after the 2.5 hour power failure. It appears as if it is "stuck" in storage mode - and this is not how I understood storage mode to work at all. Any thoughts, or ideas on how to fix this? Storage mode description from Victron documentation: "After completion of the absorption period the battery should be fully charged, and the voltage is lowered to the float or standby level. If no discharge occurs during the next 24 hours, the voltage is reduced even further and the battery goes into storage mode. The lower storage voltage reduces corrosion of the positive plates. Once every week the charge voltage is increased to the absorption level for a short period to compensate for selfdischarge (Battery Refresh mode)."

@plonkster at the risk of sounding like a stuck record... if this 3000VA Multiplus II also has the issue with that bolt - I would really like to know if mine has that issue as well. I would be a bit unhappy if my inverter is also suffering from this issue, but I only find it out once I have to start using it hard. Why can the known list of serial numbers not be published somewhere?

It would be nice to list the serial numbers on a site somewhere so users could check themselves. I.e. if your multiplus is not doing any heavy loads at the moment, you'd only find out if this is an issue once you hit heavy loads - and then it will be a bit sad.

That is really odd?

@Stanley - which issue is this change solving?

@PaBz0r - I'm keen to know more about what you used for what looks to be the bus bar just above the fused disconnect? Perhaps a closer photo as well if you don't mind? I still need to do that on my system.

Indeed, I am also curious as to how it will "reset" to 100 % like a BMV?

I checked the efficiency setting today, and it was actually set to 0.8 - so I adjusted it to 0.9. I will see how that goes. I am curious as to how the inverter does the SOC calculation, and measurement - does it use a shunt or something else like a hall effect sensor?

Thanks, I will adjust the efficiency upwards at some time.

The setup is like this: 48v bank of AGMs with only consumer / charger being the inverter (from the grid, for now) Venus GX doing the reporting No external battery monitoring The state of charge as reported by the venus console was 100 % - then we had our first bout of load shedding yesterday. The inverter was sitting in "storage mode" before the load shedding started. After 2 hours of load shedding the state of charge was reported as 95 % - very little loads running. When the grid returned the inverter switched right back into storage mode, and state of charge ended like this (about 24 hours later). I am curious as to how the multiplus does the state of charge calculation - does it have an internal shunt / hall sensor? I am not too worried about this right now - will see how far "out" the state of charge goes - but I am curious if I should perhaps change some settings on the inverter. Perhaps the charge efficiency (0.85 right now)?

Ok - but, I know what my serial number is, so could I not check if my unit is in the affected range @plonkster

Is there not a batch of these that is known, and can be fixed pre-emptively @plonkster? If they know of the issue it would be great to fix rather than to wait for it to happen.

@The Bulldog - they replied with an email on my original questions at some stage, could not find anything about this on their site.

I will be sending in my forms this week, will let feed back.

They are not budging on the AMI meter requirement, although they have recently decided to pay for the meter change themselves.

@faheem101 - to save you some trouble, find it here: https://www.sonopsolar.co.za/product/2-pole-battery-fuse-holder/ Great service from Sonop Solar.

It was the "street" 60A breaker to our house that had corroded on one side, and was slowly dying. Also had low 210V moments.

I was also wondering about this, and I'll then also apply for more than what I will install initially... was just planning on installing about 1 kilowatt for now, but can then apply for the max.

Funny, how this pops up now! I had flickering lights in my house last week, volts going down to 208 and so on. Also in an estate, and also have access to the electricity kiosks. This is what I found - the switch servicing our house was slowly melting away... It did take about 33 years to get there though 😄

I got eight of these C&D Dynasty UPS12-320MRX batteries for very cheap out of an UPS installation: https://www.blueboxbatteries.co.uk/dyn/filemanager/cd-ups12-320mrx.pdf They are 84 AH batteries, and the intention is not to use them for any cycling - just for a house sized UPS for the critical loads for when Eskom goes down. From the PDF document: From this I am trying to deduce the best way to configure the battery charger of the Multiplus II. I've so far come up with the following settings - by looking at the default settings applied when the Victron AGM battery type is selected, and the battery spec above. State of charge when Bulk finished = 85 % (Victron AGM setting) Battery capacity = 168 Ah Charge efficiency = 0.8 (Victron AGM setting, I think!) Stop after excessive bulk is enabled Storage mode is enabled Charge curve = Adaptive and BatterySafe Absorption voltage = 56V. No idea what the correct voltage is. I did find that some of the batteries in the strings were charging at higher volts than others so I lowered this until the highest battery was "safe". I have since charged each individual battery with a 12v charger. This has helped a tad, but the batteries are still charging at different rates. This is the trade off for using old batteries, I assume. Float voltage = 54V. I took the lower end of the float charging voltage from the spec above. Charge current = 17A. I used C20/10; i.e. 168Ah / 10. I see these batteries can charge at C20/5 as well - not sure if I should attempt that... Repeated absorption time = 1 hour. Default setting. Repeated absorption interval = 7 days. Default setting. Maximum absorption time = 8 hours. Default setting. Any thoughts would be great!

I've at last got some time to really get my system configured, and start using it. In my mind - Update the firmware. It is on "2628430" - so I assume I download the VFF2628459.vff firmware from https://professional.victronenergy.com/downloads/firmware under VE.BUS.../26 - 230.../400 Assistant firmwares. Use VEFlash to update the inverter, with it running from battery (it sucks having to do this from a VM on Mac). Configure it for UPS, while SSEG application is ongoing. I have a general idea what to do with the charger section, but some specific docs on Victron's site would have been great. At least I can use VRM Remote to do this bit.

Perhaps it is 11W when it is inverting from battery? And the higher wattage is the overhead of the charger (even though it is not charging anything)?

I was under the impression its "zero load power" is much lower than that - around 11W?

This is a brand new installation, not even batteries are connected yet. There is also nothing connected to to AC out 1, so I am confused as to where the power is going?