MUST Inverter (PV18-5048 VHM) Only Floating Problem

[Délbio Rodrigues]

Hi, how are you guys? I already looked all over the internet for this problem and I found similar ones but nothing that presented a solution specific to my inverter model. The model is PV18-5048 VHM, the batteries idles at 12,6v each, it's 4 batteries for a 48v inverter. When it starts, there's a bunch of current flowing and then it goes lowering and lowering the current until it reaches 1A and stays at float voltage and nothing I do changes that and I don't know what to do to keep my batteries charged. Can someone help me?

[Délbio Rodrigues]

Just another information to throw here: the inverter is reading the battery voltage and applying with 1v lower then it really is, so if it's applied 58,4v (maximum allowed), it's really 57,4v.

[Coulomb]

Some Must inverters are apparently now genuine Voltronics made. If so, you could follow the instruction here to calibrate the battery voltage.

But PV18 sounds like one of the older clone models. I don't know how to calibrate the battery voltage on those.

[Délbio Rodrigues]

Hi, Coulomb. I hope you're doing fine! Thank you so much for the reply, I'm really gonna take a look for the instructions.

 

It's a model from 2020, I'm not sure clone of what brand and model it is. I'll post below the manual if it can somehow share a light to the topic:

 

http://www.electrosistemas.com.ar/datasheets/must/User-Manual-PV18-3-5KW-VHM-off-grid-MPPT.pdf

 

Thank you again!

[Coulomb]

7 minutes ago, Délbio Rodrigues said:

I'll post below the manual if it can somehow share a light to the topic:

Battery calibration is for whatever reason not included in user manuals, unfortunately.