Axpert Inverters, are they the giant killer in off grid solar generation?
Well, the short answer is no, its not.
The Voltronic Axpert inverter (out of China) has proven to be an “acceptable” performer, but mostly (in our experience) best limited cases where the battery has its own management system, the inverter is not put under heavy electrical loads, or is used intermittently in a small system at a weekend getaway home. However it tends to need a bit of a more hands on person (i.e. the tinkerer) to get the most out of it as they can be troublesome.
It is undoubtably (on paper) good value for an inverter, pv charge controller, and AC battery charger all in one, and we certainly understand the appeal due to the diminutive cost, but the old saying applies, you do get what you pay for. That is very much the case here.
Another factor is safety – In low frequency transformer-based inverters the DC and AC sides are physically separated by the transformer (galvanically isolated), so even if the semiconductor switches fail the product is still safe.
Also the fact there are far fewer semiconductor switches in a LF transformer based inverter, again, makes it far more preferable in harsher (i.e non climate controlled) environments.
Although the Axpert inverter represents very good value on paper, it is none the less a very entry level product. The more competent and reliable low frequency transformer based battery inverter is always a better option, but of course comes at a higher cost, and for good reason. They are far more robust and dependable and therefore more suitable for reliable daily off grid energy supply.
To further confuse things, there are also clones (or copies) of the Voltronics unit that are made by different factories all over china, and these again can be of dubious quality. So, if you choose this route, be sure of the source of the unit itself and the suppliers ability to support it post sale.
So to conclude, if you’re willing to understand the role and appeal of the Axpert inverters and feel the low initial cost makes it viable despite being a low quality option, then go for it; but understand that a quality engineered LF transformer based inverter is superior and will perform better and far more reliably for many more years and under harsher conditions.