power inverter

[mr.blitz]

i have a t42 and want to use it in my motorhome.

can i run it on a modified sine wave inverter?

i heard that laptop batteries don't like modified sine wave signals...can i run it without the battery in it?

or is it simply that the t42 needs a pure sine wave signal to work correctly?

thanks for any replies.

[poshgeordie]

I guess your motorhome inverter outputs 220V AC at 50Hz from 12V DC motorhome battery in?

The Thinkpad AC adapter requires an input voltage of 110 - 250V with an sinusoidal alternating current (AC) of 50Hz to 60Hz which provides a fixed 16V DC output at up to 4.5A.

It's this 16v DC (direct current ie the voltage is fixed and smooth at 16v) which is critical for the correct operation of the Thinkpad, first to provide voltage and current for the laptop components, and secondly to charge the battery.

So providing the AC input to the AC adapter is within spec, your TP and battery should function correctly.

Don't connect the inverter directly into the Thinkpad rear DC connector unless it's 16V DC and can provide up to 4.5A, ie is NOT 16V AC (sinusoidal) or else this will permanently damage the Thinkpad.

Also you can run the laptop via the AC adapter with no battery fitted.

Hope I've understood what you're asking correctly and get back if I've got the wrong end of the stick.

[jdhurst]

Of all the places I would run any Thinkpad without a battery, a motorohome is the very last place. Just when you are completing an unsaved, but very important 35 page document of all original thought, the motorhome power will burp. I never run my Thinkpad without a battery for that very reason. It can be done, however - no dispute there. ... JDH

[Norway Pad]

I have run my Thinkpads a couple of times from a 12V DC / 110V AC inverter in my car, when I have been on the move and needed more operating time than the battery could give.

I notice that the ac adapter gives a lot more noise and gets hotter when I use it with the inverter. Probably because the sine "wave", that is not a pure wave, but a modified one, like mentioned above. Because of the noise and the increased heat I have always assumed that this put some more stress on the adapter than a regular AC power and maybe affects the adapter's lifetime if it's used like this permanently.

I do also think that the adapter is so well capable of filtering away the unwanted noise, that I have no reason to believe that the DC voltage that the adapter sends to the laptop is bad for the laptop or the battery. But the adapter obviously works harder to filter and transform the modified sine wave. It is however a bit above my knowledge to say this as a fact, it's just assumptions based on what I have seen and experienced.

EDIT: Battery or no battery: I always run my Thinkpad with no battery when it's docked for a longer period of time. But I regretted that last week when Idaho Power had problems, So after 2 outages, I ended up putting the battery back for a while.