Thinkpads Forum

Hello, I'm considering getting a 2nd power adapter for a x61 I'm about to buy. I know the 90 watt power adapter works with the x61 but will it charge faster or anything?

Fast charging does not apply to Li-On batteries, it is a matter related to NimH batteries.

Be sure to use a 20V -+ adapter, amperage must be at least 3.25 A, either adapter or battery may be damaged.

alexperez wrote:Fast charging does not apply to Li-On batteries, it is a matter related to NimH batteries.

That's not quite true. In fact, Dell Latutude notebooks with 6 cells can fully charge in 2 hours when used with 90W adapter. Regular 60W adapter takes 4 hours to fully charge.

I'm not sure how thinkpad battery charging would work with higher output adapters. I know that regular charging is slow compared to Dell Latitudes.

jamone wrote:Hello, I'm considering getting a 2nd power adapter for a x61 I'm about to buy. I know the 90 watt power adapter works with the x61 but will it charge faster or anything?

No. The unit will not charge any faster. Think of power as being "pulled" by the computer. Think of the wattage of your adapter as a hose (or pipe) through which to pull. Your laptop will attempt to "pull" the same amount of power no matter how big that pipe is.

An adapter that supports more wattage than you need is fine. I have some R40 adapters that I use with my X30. No problems there. But the reverse is not true. Do not ever use an adapter that doesn't support at least the amount of power that your device will draw.

hp79 wrote:Dell Latutude notebooks with 6 cells can fully charge in 2 hours when used with 90W adapter. Regular 60W adapter takes 4 hours to fully charge.

That is due to a rather peculiar design decision by Dell in terms of the power management and has nothing to do with battery technology per se..... as well as nothing to do with ThinkPads.

hp79 wrote:I know that regular charging is slow compared to Dell Latitudes.

And ThinkPad battery life is much better.... TANSTAAFL!

Cheers,

Bill B.

hp79 wrote:That's not quite true. In fact, Dell Latutude notebooks with 6 cells can fully charge in 2 hours when used with 90W adapter. Regular 60W adapter takes 4 hours to fully charge.

That's interesting. I wonder how it works. I'm thinking that the adapter might have some sort of current-limiting function, to ensure that the notebook doesn't inadvertently draw too much power. And then the notebook would need to be "smart" enough to figure out how much current it was getting, and what to do with it.

So I have to stand somewhat corrected with respect to my earlier note.

However, I'm not aware that Lenovo implements that sort of functionality in their Thinkpads.

I'm pretty sure I saw a page on the Lenovo site that said a 90 watt adapter could be used in place of a 65 watt adapter and it would charge faster. Of course, I can't find that page now ...

I have booth 65W and 90W and noticed no difference in charging time.