Understand your load need or you’ll likely oversize or undersize the system which will lead to you losing money either way.
There is a certain limit to every inverter. Some are great for lighting up your lights and fans, but they won’t power up your fridge or AC.
You must buy a battery that suits your requirements and is also supported by the inverter. If you buy the wrong battery then you may not be able to get adequate power.
Make sure you buy your inverters from trusted and authorised dealers. A good dealer will make sure to provide you with the best products and will always have genuine spare parts.
Inverters are technical products and an uncertified person may damage some of its core components when installing.