Hi, can someone perhaps tell me what the main difference is between the Axpert MKS IV and the Axpert VM IV please? Which one of the two is better?

They look the same I cant find anything different in the specications.

Just finding some differences in the spec sheet, in the MPPT range, the Maximum PV Array Open Circuit Voltage, and in the Maximum AC Charge current. Just the 2c of someone who doesn't use these inverters.

For PV configuration the VM IV seems better, and for running it as a UPS probably the MKS wins out, but otherwise the average user experience shouldn't be very different.

Edited August 3, 20233 yr by GreenFields

6 hours ago, Morras86 said:

Hi, can someone perhaps tell me what the main difference is between the Axpert MKS IV and the Axpert VM IV please? Which one of the two is better?

The VM is a lower cost value-line derivative of the MKS . They share the same main board , so as far as the power chain is concerned they are the same.

some known differences :

1. The MKS machines can be parralled in order to increase capacity.

2. The MKS has PWM driven fan control with feedback . The VM not , therefore the VM fans are full speed on , and are noisier.

3. The BMS battery support for VM is limited to PylonTech only.

4. There are may be more differences , maybe @Coulomb can add 

 

I'd say in general , if you don't need to parallel machines , and if  fan noise is not a real problem for you , then you will benefit from the lower cost of the VM.

 

 

Edited August 3, 20233 yr by BritishRacingGreen

12 hours ago, BritishRacingGreen said:

1. The MKS machines can be paralled in order to increase capacity.

And VM models can't.

12 hours ago, BritishRacingGreen said:

3. The BMS battery support for VM is limited to PylonTech only.

I've never used one, but the manual implies that there is a fairly full range of BMS options, and reading the display firmware confirms this. The manual I read didn't include the BAK battery type that display firmware version 122.15 has, called LIA in later display firmwares.

The other difference is that they saved a dollar or two on the DSP chip, so it's a '28062 chip with half the flash memory of the '28066 or '2809 DSP chips. That means that there isn't room for the paralleling code. But it does mean that there is no chance of a DSP chip conflict with any VM model. The display processor appears to be identical to non-VM models.

I seem to recall the main firmware cutting a few corners, but I can't recall any details at present.

Thank you very much for the replies every one, I have phoned several Solar companies and no one even knew what I was talking about lol. I really appreciate the assistance and knowledge shared on this site. By the sound of it the MKS seems to be better than the VM (ordered a MKS but the vendor sent me a VM model) hence I will request them to send me the correct device as advertised.