Dette er tatt fra en eller annen kar som jobber i et eller annet blad og er klippa fra et eller annet forum...
Veit det er en og annen av dere som er fryktelig intreserte i PSPens batterier så jeg tenkte dette kunne være greit å poste.
zmcnulty came out of the closet to say:
Yeah, I know there's already a PSP thread on page 1. But hell, this is the sort of stuff everyone has been waiting for, right?
A lot of theorizing in here, so if you're looking for concrete details, too bad.
Yeah, I know there's already a PSP thread on page 1. But hell, this is the sort of stuff everyone has been waiting for, right?
A lot of theorizing in here, so if you're looking for concrete details, too bad.
Opprinnelig skrevet av me at work
I'm not an engineering major, and I hate math. That's my disclaimer. Also, this article will get very technical. If you're not into that sort of thing, I suggest you steer clear of what's going on here, and wait for Sony to make an official estimate of PSP battery life.
Being that I speak a bit of Japanese, I come across some gaming information earlier than most people. One of the articles I ran across earlier this week was this:
PC Watch article (Japanese)
It is a report from a technical conference held last month - August 22nd to 24th - called "Hotchips 16," run by Sony LSI Design. Sony chose to announce a couple details about the PSP chipset at this event.
Apart from the PSP supporting 720 x 480 video decoding (which is quite interesting considering the PSP's screen is only 480 x 272), one of the key technical details announced was that during video playback, the power consumption of the PSP chip is less than 500mW. mW is milliwatts, for those of you that don't know.
According to the article, decoding H.264 (the PSP's video format) takes more processor power than decoding MPEG-4. As the article continues, the writer explains that because of this, it is safe to assume that decoding H.264 at 720 x 480 puts a heavy stress on the processor. So heavy, in fact, that it basically parallels the stress placed on the processor during gaming. Reportedly.
Continuing, he gives a couple examples of what sort of battery life the unit would have given certain capacities of battery. He says that for the unit to playback video for 8 hours, and the average power consumption were 800mW, a battery with a 6.5Wh (watt hours) capacity would be needed. With a 10Wh battery to get 8 hours, you'd need an average power consumption of 1.25W. The math for this is pretty simple:
6.5Wh = 6500mWh
6500mWh / 800mW = 8.125 hours
10Wh = 10000mWh
1.25W = 1,250mW
10000mWh / 1,250mW = 8 hours
Pretty simple, right?
Now take a look at this link:
http://www.consoleconspiracy.com/News/arch..._09.html#000100
This page reports the PSP's battery capacity as 1,800mAh. So what's the problem? Why can't I finalize a PSP battery life?
mAh (milliamp hours) and Wh (watt hours) are two different units. mAh is a measure of cell capacity; Wh is a measure of cell energy. Without knowing the voltage of the battery itself, we can't convert the units.
As far as I know, Sony hasn't publicized the voltage of the battery. When the information comes out, the formula for converting Wh to Ah would be something like:
Ah = Wh / Voltage (V)
or
Wh = Ah * Voltage
As you can see, the difference between Ah and Wh is that while one measure contains voltage, the other doesn't.
But hell, that's what guessing is for. And what better place to make guesses than the internet? For some "intra-corporate" comparisons, let's take a look at an assortment of other Sony batteries:
First comes the high-ball - camcorder batteries. And I say "high-ball" because camcorder batteries have a voltage probably too high for PSP-type applications.
http://www.amazon.com/exec/obidos/tg/detai...070333?v=glance
This camcorder battery has a 1500mAh capacity, and is reported to be 10.8Wh. Why? The battery is 7.2 volts.
To put some math to this, and to demonstrate my earlier formula for converting Ah to Wh:
Ah = Wh / Voltage
1.5Ah = 10.8Wh / 7.2V
Try the reverse too, if you want.
So for purposes of the high-ball, let's assume the PSP has a 7.2V battery as well. If we plug in our 1800mAh figure presented at the Austin Game Conference, and combine that with the 500mW power consumption announced by Sony at Hotchips 16, we end up with:
Wh = Ah * Voltage
Wh = 1.8Ah * 7.2V
Wh = 12.96
12.96Wh = 12,960mWh
12,960mWh / 500mW = 25.92 hours
That's right...if the PSP contained a 7.2V battery, it would get around 26 hours of battery life. If, you know, it consisted of just a single chip. Which it doesn't.
Next is the low-ball. Since I own a Clie T665C, I'll use its battery.
http://www.batteries.com/products/PDA/Sony...DA_Battery.html
This is a 3.7V battery. I'm pretty sure Sony would put a battery more powerful than the one in my old ass PDA for their next generation portable. But it's a low-ball, so here goes:
Wh = 1.8Ah * 3.7V
Wh = 6.66
6.66Wh = 6,660mWh
6,660mWh / 500mW = 13.2 hours
13.2 hours still seems a bit high, even for a low-ball. I'll go lower.
A normal AA battery has a voltage around 1.5V.
Wh = 1.8Ah * 1.5V
Wh = 2.7
2.7Wh = 2,700mWh
2,700mWh / 500mW = 5.4 hours
"What the hell is going on here? Are you saying the PSP is going to have a long ass battery life?! Even if it has just one AA battery, it can run for almost 6 hours?"
No, I'm not saying that. First of all, this power consumption figure (the 500mW) appears to be just the PSP chip. The are plenty of other components that will consume power, such as the UMD drive, wireless, controls, and most importantly, LCD.
Second of all, this 500mW figure isn't during gaming. Sony hasn't announced what the power consumption of the chip will be during gaming. The author of the Impress Watch article feels as though since it can decode H.264 (which, remember, takes more processor to decode than MPEG-4) at 500mW, it should be able to play games without too much more consumption.
Frankly, I'm leaning towards "agree." Based on the above figures (presuming they're right), and the history Sony has of its products battery lives, I am no longer concerned.
I'm not an engineering major, and I hate math. That's my disclaimer. Also, this article will get very technical. If you're not into that sort of thing, I suggest you steer clear of what's going on here, and wait for Sony to make an official estimate of PSP battery life.
Being that I speak a bit of Japanese, I come across some gaming information earlier than most people. One of the articles I ran across earlier this week was this:
PC Watch article (Japanese)
It is a report from a technical conference held last month - August 22nd to 24th - called "Hotchips 16," run by Sony LSI Design. Sony chose to announce a couple details about the PSP chipset at this event.
Apart from the PSP supporting 720 x 480 video decoding (which is quite interesting considering the PSP's screen is only 480 x 272), one of the key technical details announced was that during video playback, the power consumption of the PSP chip is less than 500mW. mW is milliwatts, for those of you that don't know.
According to the article, decoding H.264 (the PSP's video format) takes more processor power than decoding MPEG-4. As the article continues, the writer explains that because of this, it is safe to assume that decoding H.264 at 720 x 480 puts a heavy stress on the processor. So heavy, in fact, that it basically parallels the stress placed on the processor during gaming. Reportedly.
Continuing, he gives a couple examples of what sort of battery life the unit would have given certain capacities of battery. He says that for the unit to playback video for 8 hours, and the average power consumption were 800mW, a battery with a 6.5Wh (watt hours) capacity would be needed. With a 10Wh battery to get 8 hours, you'd need an average power consumption of 1.25W. The math for this is pretty simple:
6.5Wh = 6500mWh
6500mWh / 800mW = 8.125 hours
10Wh = 10000mWh
1.25W = 1,250mW
10000mWh / 1,250mW = 8 hours
Pretty simple, right?
Now take a look at this link:
http://www.consoleconspiracy.com/News/arch..._09.html#000100
This page reports the PSP's battery capacity as 1,800mAh. So what's the problem? Why can't I finalize a PSP battery life?
mAh (milliamp hours) and Wh (watt hours) are two different units. mAh is a measure of cell capacity; Wh is a measure of cell energy. Without knowing the voltage of the battery itself, we can't convert the units.
As far as I know, Sony hasn't publicized the voltage of the battery. When the information comes out, the formula for converting Wh to Ah would be something like:
Ah = Wh / Voltage (V)
or
Wh = Ah * Voltage
As you can see, the difference between Ah and Wh is that while one measure contains voltage, the other doesn't.
But hell, that's what guessing is for. And what better place to make guesses than the internet? For some "intra-corporate" comparisons, let's take a look at an assortment of other Sony batteries:
First comes the high-ball - camcorder batteries. And I say "high-ball" because camcorder batteries have a voltage probably too high for PSP-type applications.
http://www.amazon.com/exec/obidos/tg/detai...070333?v=glance
This camcorder battery has a 1500mAh capacity, and is reported to be 10.8Wh. Why? The battery is 7.2 volts.
To put some math to this, and to demonstrate my earlier formula for converting Ah to Wh:
Ah = Wh / Voltage
1.5Ah = 10.8Wh / 7.2V
Try the reverse too, if you want.
So for purposes of the high-ball, let's assume the PSP has a 7.2V battery as well. If we plug in our 1800mAh figure presented at the Austin Game Conference, and combine that with the 500mW power consumption announced by Sony at Hotchips 16, we end up with:
Wh = Ah * Voltage
Wh = 1.8Ah * 7.2V
Wh = 12.96
12.96Wh = 12,960mWh
12,960mWh / 500mW = 25.92 hours
That's right...if the PSP contained a 7.2V battery, it would get around 26 hours of battery life. If, you know, it consisted of just a single chip. Which it doesn't.
Next is the low-ball. Since I own a Clie T665C, I'll use its battery.
http://www.batteries.com/products/PDA/Sony...DA_Battery.html
This is a 3.7V battery. I'm pretty sure Sony would put a battery more powerful than the one in my old ass PDA for their next generation portable. But it's a low-ball, so here goes:
Wh = 1.8Ah * 3.7V
Wh = 6.66
6.66Wh = 6,660mWh
6,660mWh / 500mW = 13.2 hours
13.2 hours still seems a bit high, even for a low-ball. I'll go lower.
A normal AA battery has a voltage around 1.5V.
Wh = 1.8Ah * 1.5V
Wh = 2.7
2.7Wh = 2,700mWh
2,700mWh / 500mW = 5.4 hours
"What the hell is going on here? Are you saying the PSP is going to have a long ass battery life?! Even if it has just one AA battery, it can run for almost 6 hours?"
No, I'm not saying that. First of all, this power consumption figure (the 500mW) appears to be just the PSP chip. The are plenty of other components that will consume power, such as the UMD drive, wireless, controls, and most importantly, LCD.
Second of all, this 500mW figure isn't during gaming. Sony hasn't announced what the power consumption of the chip will be during gaming. The author of the Impress Watch article feels as though since it can decode H.264 (which, remember, takes more processor to decode than MPEG-4) at 500mW, it should be able to play games without too much more consumption.
Frankly, I'm leaning towards "agree." Based on the above figures (presuming they're right), and the history Sony has of its products battery lives, I am no longer concerned.
