AC adapter compatability with 770

[brchan]

Will a T43 charger work and be safe to use with a 770? Thanks.

[rkawakami]

Plug it in and do a "smoke test" . The 770 appears to have shipped with a 56W adapter (16V 3.5A). The T42 would have shipped with a 72W adapter (16V 4.5A). So yes, you can. However, the opposite is not recommended (running a T42 using the 56W adapter).

[Neil]

Yeah, what Ray said. I've always run my 770 (and 600 series) ThinkPads with 72W 16V adapters...no problem.

[brchan]

Awesome, thanks!

[rkawakami]

The thing to remember about AC adapters is that you can safely use a higher-amperage (DC output) supply on systems that require less power. Put another way, always buy 16V 72W (4.5A) adapters so you can use them on any Thinkpad that accepts 16V input via the "standard" 5.5mm diameter (black) barrel connector.

[ilakast]

^^
Unless one cares about size and weight, that is. Then, AC adapters get smaller in size as wattage goes down.

[rkawakami]

The few ounces (or many grams) of difference between the 72W and 56W adapters isn't that much, as well as the small difference in length/width/depth. In my mind, it beats having to worry about which adapter I'm using on what laptop (when you have as many "legacy" 16V systems as I do). You would also be buying "for the future" in case you end up with another Thinkpad which requires the 72W adapter.

[tfflivemb2]

I agree with Ray. The weight and size difference is so negligible, compared to the versatility, IMHO.