Revision Numbers of Power Supplies

[Wendy]

I have three 60 watt power supplies that came with 3 different thinkpads. How do I know which revision is the most recent? I tried search and couldn't find an exact match to my question.

I have a rev D, H, and J

Also curious about efficiency level: IV vs V

Does it really matter?

TIA

[eyestrain]

Seems that V is more efficient than IV. Not the most helpful link, but it does have some info: http://www.oee.nrcan.gc.ca/residential/ ... cfm?attr=4

I would think that V should make less heat in the power supply itself, and save a tiny bit of energy and money.

I would favor the level V with the thickest cord near the laptop, for the one used the most. When I've had problems with TP power supplies, that's usually been the area.

Maybe others have more info.