What Size Power Inverter Do I Need? The size you choose depends on the watts (or amps) of what you want to run (find the power consumption by referring to the specification plate on the appliance or tool). We recommend you buy a larger model than you think you'll need (at least 10% to 20% more than your largest load). Specification: 1. Solar Panel 18W: Power: 18W± 5% Size: 420x280x2.5mm DC output: 12V/1.5A USB output: 5V/1.7A Weight: 0.7kg Type: Mono Solar Panel Material: Aluminum substrate Output accessories: DC cable + DC alligator clip 2. Power Inverter 4000W: Input voltage: DC 10.5V~15V, (When the battery voltage is lower than 10.5V, the inverter is low voltage protection, when the battery voltage is higher than 15V, the inverter high voltage protection) Output voltage: AC 110V for your choice Output frequency: 60Hz Rated power:300W(Please make sure that the total rated power of the connected devices is ≤ 300W). Output waveform: Modified sine wave Product Size for inverter: 165x112x56mm 3. 30A 12V 24V Automatic Solar Charge Controller PWM with LCD Controller and Dual USB Charge Current: 30A Product Size: 148.5x78x35mm Display: LCD digital display USB Charger Ports: Dual USB 5V 2.1A Operating Temperature: -35~+60 Max Solar Input: 12V battery, the highest 23V Float Charge: 13.7V (defaul, adjustable) Discharge Stop: 10.7V (defaul, adjustable) Discharge Reconnect: 12.6V (defaul, adjustable) Charge Reconnect: 13V Voltage of Open Light: Solar Panel 8V (Light lights delay) Voltage of Close Light: Solar Panel 8V (Light off delay) USB Output: 2 way USB output, 5V/2.5A (MAX) Packing included: 1 x Power Inverter 2 x Battery Clip 1 x Cigarette Lighter Plug(gift) 1 x User Manual 1 x Solar Panel 18W 18V+DC cable + DC alligator clip 1 x Solar Charge Controller 30A 12V/24V