Jacques1982

The 43.xx firmwares are a jumble, some VM II older, some VM II newer/premium, some VM III, even a small Max (3.6 kW dual MPPT). I have not seen anything that would match your model, sorry.

So I have purchased some cells and am waiting some parts before I can start building them.
 
Whether it is cheaper, well, it depends on what price you can get the cells for although with the prices of some already built batteries which have recently come onto the market it does not make sense to DIY if cost savings is what you are after.
 
For example, I have seen the Svolt 106AH batteries being advertised for under R20k brand new, like here: https://www.snaga.co.za/product/svolt-51-2v-106ah-5-43kwh-lifepo4-battery-wall-mounted/
Altergrid are selling some 280AH Eve cells for R3200 each (https://altergrid.co.za/product/eve-280ah-3-2v-lifepo4-cell/?gclid=Cj0KCQjwl8anBhCFARIsAKbbpyT9CQ90o8oOfB0IthDxd0YzshnAZ3XHCkPF4lSlDzOwFLq2XjwKEYsaApCpEALw_wcB)
 
So 16 cells would come to R51 200 and then you need a BMS which would be cost between R2700 and R4100 if purchased from Altergrid as well.
So now we are at R55 300 and you still need to assemble it, create an enclosure of some sort (or have it on a shelf if you do not mind the way it looks and the possibility of it being pulled off). I'd say you could likely construct a nice enclosure from MDF and spray it and floor mount or wall mount it for around R1500 - R2000.
So R58 300 approx final cost for the DIY battery with 280AH.
 
For R58 500 (an extra R200) you could purchase 3x 51.2v 106AH Svolt batteries and have a total of 318AH and the convenience of just taking it out the box, mounting it on your wall and wiring it up - plus you get a warranty from Svolt and the comms between your inverter and battery are not as much of an issue as they are with a DIY battery (most run their DIY batteries without comms between the battery & inverter).
 
So basically, the pricing on some of these new batteries makes the cost aspect of buying your own battery a bit of a mute point I feel, unless you are able to get the cells at a really good price