#1: Not True. I think it's worth knowing if you have pure or modified
sign wave for other reasons (microwave ovens for example need a lot
more power under one vs the other), but for laptops it does not matter.

#2: Check out the vendor's web site support area or call them. If they
say pure sinewave, and there not boasting about it on their website or
manuals as a feature of their inverter, I would be suspicious you got
the correct answer.

I power my laptop computer via my boats battery, saving a little bit of
energy, plus I avoid generating annoying noise. I also power my TV and
DVD thte same way, using DC to DC adapters ...

http://www.powerstream.com/Produz10.htm

The microwave still uses the inverter, but nothing else. The benefit
was eliminating any noise from the audio output of the TV (in
combination with using an RCA to RCA filter between DVD and TV, to deal
with a ground feedback issue), and eliminating noise from the cabin
(from the inverter, hum and/or fan)

Dan
Huntington, NY


Floating Mind wrote:
It's my understanding that a person should never use a modified sinewave
inverter with a laptop, that we should always use pure sinewave
inverters with laptops, as the modified sinewave units are harmful to
the life of the laptop's battery.

Question #1: Is this true?

Question #2: How do I tell the difference? I have 2 inverters I use on
my boat, each from a different manufacturer, and neither one says
anything about the sinewave characteristics.