Wednesday, July 31, 2013

What Is The Difference Between 65Watt and 90 Watt AC Adapter

A watt which measures laptop power is a unit of measurement for power. This particular unit could measure power, or capacity to do work. Watt’s law states that one watt (1W) is how much power is in an electrical circuit where one ampere (1A), or amp, of current flows across a difference of one volt (1V). AC adapters convert electricity in alternating current form from one voltage to another. If you are looking at two AC adapters that both convert, say, 120V AC to 12V AC, it can be confusing to see different wattage ratings (such as 65W vs. 90W) for the two adapters.

An AC adapter with a rating of 90 watts with an output of 12 volts AC will have a maximum electrical current output of 7.5 amps (12V x 7.5A = 90W). Therefore, an AC adapter with a higher power rating (measured in watts) will be able to supply more current to a device it’s connected to.

While an AC adapter with a higher power rating will allow for faster battery charging times and increased electrical loads, an AC adapter with a lower power rating may suffice, especially where there is a concern about excess heat or higher cost, for example, HP pavilion DV6 AC Adapter, it has two versions: DV6 65Watt AC adapter and DV6 90Watt AC adapter, abd the higher power adapter is better than the 65Watt at sometimes, users who like playing games or some sofeware which need much power to support to run will need the more powerful version.

Similarly, since the power rating is considered to be a “maximum allowable power” indication, an AC adapter may be used to power devices that are rated at or below their power rating. If a device requires 12V and 3A (36W), either the 65W or 90W power supply may be used to power it.

Cost may also be a factor. Usually, since AC adapters with a higher power rating must be capable of delivering more electrical current for the same amount of voltage, the components required to assemble an AC adapter must be more robust than that of a lower-power-rated AC adapter.

AC adapters with higher power ratings also give off more heat than adapters with lower power ratings. If excess heat is a consideration, an adapter with a higher power rating may not be suitable for the application.


  1. Thank you for putting an effort to published this article. You've done a great job! Good bless!

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  2. IDsonix Socket Outlets from Bizarkdeal

    This is a great, high-capacity charger, with attractive and functional design, that accomplishes what it sets out to do.

    VISUALS: I tend to like pure white charging strips and cords, because they tend to blend into the white baseboards that most homes and offices have. It takes up less visual space in many/most settings.

    AC CHARGING: Having 4 AC outlets, rather than fewer, is a convenience; to have more than that, would result in a much bigger strip. This is a good compromise. The placement of the ports is unusually wise, with ample space, such that only the largest plugs will cover up a second outlet. It is a fairly big unit, because of the extra space it provides between the 4 AC slots. It is still reasonably sized, and I am happy to make that tradeoff; however, is space is a constraint for you, you could probably find a smaller unit.

    USB CHARGING: The USB charging speed for multiple devices seems to be as fast as any USB chargers I have tried. This type of design is much more cost effective than plugging separate USB chargers into a power strip. You should not exceed the total amps that it is designed for by simultaneously charging high amp devices on most of the ports; however, that would be a rare situation given our usage. Additionally, it does not seem to run hot, which is typically the biggest concern with multi-outlet chargers.

    OVERALL: If you want a white, 4 AC, 5 USB charger, this seems like an excellent choice. I am glad I bought it.

  3. Thank you for the info. It sounds pretty user friendly. I guess I’ll pick one up for fun. thank u.

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  4. Thank you! That was great... Answered exactly what I needed to know about 65 vs 90w. Thanks so much!!