Also: be aware that all inverters are not created equal. Some are 'pure sine wave', some are rough or 'saw tooth' sine wave. Make sure the device you are powering with the inverter likes (is compatible with) the type of sine wave your inverter produces. Many devices can be damaged by inverters that are not pure sine wave. Cheaper inverters tend to produce rough or saw tooth waves. As in most things, you get what you pay for...
Classic Prius Chat routine of getting people to spend more then they need.... The key reason to buy a Pure Sine wave is if you're powering home appliances or expensive communication / entertainment equipment during power outages. And if you just need to power some light bulbs, you can plug the bulbs straight into the pack and you don't even need a power inverter. There's actually lots of things around the home that don't care if you've using 220v DC or standard outlet 110v AC. Just gotta experiment...
If you take the time to figure out what you want to operate with that inverter power, you may find that a cheap modified sine wave unit is fine. If you want the flexibility of not knowing or caring, just get a pure sine wave unit and you’ll be covered. Stuff that often has a problem with modified sine wave: Fans Refrigerators kitchen appliances & hand tools with motors Fluorescent lighting Older electronics- especially old hi-fi gear, 2-way radios, tube TVs microwave ovens Stuff that probably won’t care: Phone & tablet chargers Laptop chargers halogen & LED lighting modern flatscreen TVs electric blankets coffeemakers & slow-cookers
In my experience, "modified sine wave" is one of those terms like "100% juice with added ingredients". You look at the output, it's essentially a square wave, except it rests at zero a little bit between half-cycles. The closest it gets to a sine wave is on the back of the box, where somebody from the art department draws a sine wave next to it. It'll usually run hand tools sort-of, but they'll sound weird and buzzy and may run unstably, especially if they contain their own electronic motor controls, as more hand tools recently do. I would be quite cautious about trying to run laptop/phone/etc. chargers from one, because most of those things are switch-mode power supplies in their own right: they try to regulate their own output by rapidly cutting in and out from the supply coming in. The interaction could be weird when that incoming supply itself is abruptly cutting in and out, rather than varying smoothly. I think I've got something like three old MSW inverters lying around that I haven't used in years, but also haven't taken to Goodwill or the Re*Store because I don't relish inflicting them on anybody else. Back in the day, true sine inverters were a lot more expensive than MSW, but the price gap has narrowed enough now that I don't see much of an argument for MSW.
