I'd keep it. You wont regret it. I cant stress enough how many cheap sh*tty inverters try to pass off as acceptable, and will wreck your stuff, freeze your computer or make things hot and emit buzzy sounds. Also, 300 watts is great, better to have extra power than being maxed out with a smaller inverter. Laptop brick might draw 90w max. But now you can add a few things in there simultaneously no worries. I have a samlex pure sine wave unit, I it is probably the best money I have ever spent, and your morningstar unit is even nicer - no fan and sealed.