I have been running the above 3Kva inverter for some time now and has worked fine for my needs.  I was offgrid for about 4 or 5 years, then ongrid for a couple and now recently back offgrid.  I recently upgraded to a MUST LP18-48100 battery and now seem to be suffering from the premature float bug.  My software version is 02.51 (U1) and 02.10 (U2).

Is there by any chance of a patched software version that I can install to overcome this problem?

Thanks in advance,

Peter

Must do their own firmwares these days, I don't study them at all.

This one might be from back in the era when Must inverters were Axpert clones, so this might have Axpert firmware. I do have some Axpert 02.xx firmwares that cover 3 kVA. Alas, these have the dreaded 8-bit processor, and that stuff is a nightmare to work with. Also, my patching system is only set up for TI processors, so chances are vanishingly small.

[ Edit: Duh! I had no idea that Must made batteries, and I misread the post. So I incorrectly assumed that the inverter was a Must brand. Sigh. ]

Sorry.

Edited January 8, 20242 yr by Coulomb

Hi Coulomb, thanks for the speedy reply.  I might have been a bit vague.  My inverter is an Axpert, don't think it is a clone, although branded Mecer.  It is about 5 or 6 years old.  How would I determine whether the processor is 8 bit or otherwise?   The battery is a Must, recently bought.  I have no comms between battery and inverter, quite honestly, because I don't know how to connect to the funny USB port on the inverter.  I did manage to connect the inverter to MultiSIBcontrol, via my tablet, but this just confused me more, in that the battery displayed 2 out of 6 lit LEDs but the program said it was at 86% SOC.  I'm guessing this is the Axpert tendency of confusing Volts and SOC, which has been spoken about a lot on this forum.  I am in the process of sorting out a RS485 to USB cable/converter so that I can read the battery info directly from my tablet using PBMSTools, if I can get it to work.

Edited January 8, 20242 yr by dax021

5 hours ago, dax021 said:

My inverter is an Axpert, don't think it is a clone, although branded Mecer.

My bad; I misread your post. As soon as I saw "Must", I assumed that this was the brand of the inverter. Sigh. Mecer are legitimate Voltronics resellers.

5 hours ago, dax021 said:

How would I determine whether the processor is 8 bit or otherwise?

You would have to look at the processor chip inside the inverter; the 8-bit chip is smaller and has fewer legs. Often (possibly always), the 8-bit processor is soldered directly on the main board, not via a control board.

Despite my confusion, my conclusion stands: it's very unlikely that patched firmware will appear for this model, unless it turns out that it's a 32/16-bit TI DSP, and a suitable firmware update file turns up.

Sorry.

Quote

I'm guessing this is the Axpert tendency of confusing Volts and SOC,

Yes. Axperts have no real idea of an LFP battery's State Of Charge, unless they have a connection to the battery BMS. Your model certainly can't do that.

Edited January 8, 20242 yr by Coulomb

Thanks Coulomb, your input is greatly appreciated.  I'm not going to stress about it for now, the battery is coping with the loads through the night and getting close to full charge if the sun shines the next day.  Once I get the RS485 to USB link working, I hope to read the BMS directly on my tablet then I can see exactly what is going on.