1. For inverters less than 500va, the battery capacity should be less than 150ah, and for inverters greater than 500va and less than 2000va, the battery capacity should be less than 200ah. If you want to extend the power supply time and increase the battery capacity, please add a charging device to the battery, because when the battery capacity is too large and the charging time is too short, the battery may be undercharged and the inverter may be overheated due to charging. And damage; at this time, the external charger can protect the inverter and also allow the battery to maintain sufficient power. (Above the inverter for 12v and 24v DC input).

　　2. A brief calculation of battery power supply time: 100ah12v=1 degree (electricity); 1000w x 1 hour=1 degree (electricity), and so on. (When the discharge current of the battery is large, the electric energy released will be less than 1 degree) For example: 　The actual power used by the user is 1000w and needs to supply power for 4 hours. The battery capacity configuration is: 1000w x4h = 4000wh = 4 kWh; the battery should be optional 100ah12v (=1 kWh) four sections, or 200ah12v (= 2 kWh) two sections.　Note: The greater the discharge current, the less energy the battery can release.

3. When charging, connect to the mains and set the switch to the "on" position, adjust the charging current adjustment switch on the panel, so that the charging current value is about 10% of the battery capacity, but the maximum charging current value must not exceed the rating of the machine Charging current, otherwise it will damage the charger.

Please kindly take a view and better to understand us:

3000w 12v 120v pure sine wave inverter