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Not getting the run-time that reviewers all got with a mobile device? You might want to check that battery capacity if you can. jkkmobile checked his Dell Mini 9 battery and found that it only had 24 Whr of capacity, while it should have 32 Whr […]

msi-wind-batteryNot getting the run-time that reviewers all got with a mobile device? You might want to check that battery capacity if you can. jkkmobile checked his Dell Mini 9 battery and found that it only had 24 Whr of capacity, while it should have 32 Whr of juice. That would explain why his 3-cell unit sees around three-hours of run-time while reviewer got four-hours.

Sadly, this isn’t the first time something like this has happened. When the Asus Eee PC 900 hit the streets in some countries, it came with a 4400 mAh battery while reviewer units had a higher-capacity 5800 mAh power pack. Asus eventually offered a trade-up style program for unhappy customers. That’s all well and good, but it’s not the solution here from a consumer standpoint.

Making matters more confusing is when a device maker offers both 3- and 6-cell batteries. You’d think that a 6-cell has twice as much capacity and therefore you’ll see twice as much run-time over a 3-cell battery. That’s not always the case because we’ve seen some devices with lower-capacity 3-cell units. The 3-cell for the MSI Wind is 2200 mAh, for example, so you’d think the 6-cell has a 4400 mAh capacity right? Some do, but others like mine offer 5200 mAh in the same form factor, so you’ll see nearly 20% more run-time with the latter, all things being equal.

Here’s what I’d like to see: clear and common language used to describe the battery and the device’s range of power usage in a given hour. And this should be industry-wide as well, i.e.: some standard. Today it’s all too common to see a netbook battery described as a 3-cell or 6-cell unit, for example. What does that really tell a consumer? It show how many battery cell components make up the inside of the single battery pack. Alone, it doesn’t specify how much capacity the cells have, and therefore the capacity of the battery itself. Better would be two additional units of measurement: the number of Whr or hours the battery can provide one Watt of power, coupled with a range of (or the maximum of) the wattage requirements for the device itself.

My MSI Wind netbook might use up to 10 or 11 Watts when running under normal usage, i.e.: backlight set to 50%, WiFi on, etc… While this number can vary based on my usage needs or power settings, it offers me a baseline power requirement. If a manufacturer told me that a 6-cell device battery has a 52 Whr capacity, simple math tells me that I can expect roughly 5 hours of use, give or take. I’m not looking for an exact run-time because that will wildly vary based on an individual’s usage of the device. I’m simply looking for useful, basic information that’s commonly used across all device choices, regardless of manufacturer.

  1. Richard Garrett Thursday, December 18, 2008

    In a related bit of news, HP and Boston Computer have teamed up for a ‘green’ battery – one that recharges to its original capacity throughout its life and is said to use fewer (if any) heavy metals. HP will offer it as a $30 upgrade on select laptops beginning early ’09. This according to NPR and John Dodge at http://www.designnews.com/blog/Green_Engineering/10596-HP_Enlists_Boston_Power_s_Green_Notebook_Batteries.php

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  2. GoodThings2Life Thursday, December 18, 2008

    I definitely agree on advertising the power specs more thoroughly and consistently.

    I’m pretty tech savvy so I know what to look for when I buy a system, but I know that most consumers have no idea what to look at.

    The MAH number is great, but only if you know what the device is supposed to draw given certain conditions.

    I know Toshiba and Dell (among others I’m sure) offer Power Management software of their own, so I see no reason why those programs can’t be made to display that sort of diagnostic information on an “advanced” screen too.

    For example, I’m on battery and I want to see just how much power is drawn with wifi on and display at 50% versus 80%… I should be able to get that info without booting to BIOS or finding some complicated tech program.

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  3. Thanks Richard. We covered the Boston Power / HP news last week: http://jkontherun.com/2008/12/10/boston-power-hp/ Definitely something I’m interesting in seeing, but bear in mind that the technology doesn’t make the battery run longer on a single charge. It benefits by allowing the battery to retain its charge over many more charging cycles.

    GT2L: I completely agree. More “tech-savvy” individuals might be able to determine the battery capacity and device power draw, but these concepts are unknown to most consumers. The industry could stand to make this all a little easier for everyone.

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  4. Richard Garrett Thursday, December 18, 2008

    Kevin, as usual you guys are all over it! And as long as we are talking power, I am following your off-the-grid charging experiment with a lot of hope. No telling how much energy we could save if we are all able to unplug a few transformers and power bricks. Thanks and here’s to long doses of quality sun on the south side of jkmanor northeast!

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  5. We do need some kind of level playing ground when it comes to batteries. All too often it seems like you have to dig deep and pull teeth to even find out if a netbook comes with a 3- or 6-cell battery. Providing this information up front will help sell systems! As we become more mobile, we all need this information to know if a battery will get us through the day. Better reporting programs (or better functionality built-in to an OS) would also go a long way in helping us understand how we’re burning through our watts.

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  6. You might want to check your units. It’s Whr, watt hours, ie how many hours can the battery provide one watt for. W/hr, Watts per hour means absolutely nothing.

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  7. inomine, good point as I didn’t define the term correctly. Making the change to the definition, although the math involved for run-times doesn’t change. Thanks!

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  8. I’d settle for just the Watt-hour rating. Everything else is semi-subjective (3-cell, 4-cell, etc. *do* mean something if we’re consistently dealing with 3.7v AA-sized Li-Ion cells, but I can’t even trust that.)

    A 50 Wh battery pack, however, is a 50 Wh pack, no matter how it’s made. It doesn’t matter if the system using it sucks down 5 watts when idle, 100 watts at full tilt, etc. You can, after all, cook benchmarks to get battery life estimates to match your projections. Just look at Apple. As much as I love their products, I usually subtract at least one hour from any battery life estimate that they provide.

    Give me nothing more than a Wh-rating, and the best/worst case estimates (Airplane mode, no gaming, minimal drive access vs. all radios running, full brightness, all spindles running,) and I’ll be happy, though I still wouldn’t entirely trust the numbers.

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  9. The Inspiron Mini 9 is configured with, and has never shipped with anything but, 32WH batteries. A third-party test software program being used in the field doesn’t properly program every vendor’s battery to report power (versus current) capabilities, and so the utility is not properly reporting the actual battery capacity. We have confirmed this and all packs are 4-cell 32Whr, and will deliver more than 4 hours of battery life in typical usage.

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