Battery Life compromise.


ShleeDragon

Pro-Catflip
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Aug 28, 2010
Messages
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People want a smaller unit.

People want a better SOC.

People want a HD screen.

People want things.

The battery would likely need to be increased to get the same life which will require compromise.

What is the lowest length you would be happy with.. 5 hours?
 
Well, all components are improving at the same time (ARM processors have constant consumption while they improve in performance, OLED screens have small consumption too), so there's no reason the life of the battery has to go lower than the current one. 

The battery life is a killer feature for many users. I don't think compromising by 50% on that aspect is very reasonable. and we dont need HD screen (if you mean 1080p screens?). HD-ready screens are good enough for this kind of size. Retina is bullshit anyway. 
 
I'd like the same battery as the P1 (since batteries tend to die on old equipment and make them unusable).

Min. battery life under high load: 8hours
 
I would be willing to accept a slightly lower battery life under high load (i.e. something that keeps all cores completely busy), but I would very much like to have an improved battery life under low load. Currently I get about 15-20 hours of low-medium load use out of the Pandora (doing things like coding, i.e. mostly text editing with some compilation in between). It would be great if that could be improved to 25-30 hours. With a big.LITTLE architecture, it should be possible to have less cpu power consumption than we have now in that scenario. With an OLED screen, even if it's bigger and higher res, it should also be possible to have less display power consumption if the screen is mostly dark pixels (as is the case when I'm doing terminal stuff, I always use bright text on a dark background). I also expect current-gen wifi to be much less of a power drain.

So it should certainly be possible to improve low-medium load battery life, and I think we should go for that. Improving the worst-case high-load power consumption is not that important to me; I'm fine with "only" 5 hours of battery life when all cores are crunching away and the display is showing all white pixels at maximum brightness.

It would be a good idea to make the P2 battery-compatible with the P1. The weight of the P1 is fine, there is no need to make the P2 any lighter.
 
I'm not pushing in any direction yet. Just saying that I think it's safe to say the low functionality power usage will increase when iding, and the peak performance will increase the usage a lot.

I'm trying to find figured related to any of the new A15 SOCs without much luck... the information for the screens should be easy enough
 
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People want a smaller unit.

People want a better SOC.

People want a HD screen.

People want things.

The battery would likely need to be increased to get the same life which will require compromise.

What is the lowest length you would be happy with.. 5 hours?
If all those aspects ^^^^ were optimized then 5 hours would be the minimal allotment. Preferably 8 hours to equate a working day but I wouldn't expect such.
 
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i dont intend to get a Pandora 2 but if i could use a Pandora 2 battery in my Pandora that would be great (because i'm assuming they'd get hard to replace in about a decade)
 
The Pandora 1 has a battery life of 5 hours under the heaviest possible load (max brightness, 100% cpu, overclocked, heavy wifi and SD transfers), 10 hours under normal heavy load, 15 hours under medium load, 25 hours under low load. So let's call that 5-10-15-25 hours.

I'd like the Pandora 2 to match that, at least for doing the same tasks as the Pandora 1. Something like PCSX ReARMed is "heavy load" for the Pandora 1 but would probably be "medium load" for the Pandora 2. Taking that into account, something like 2-5-10-25 hours of battery life would be enough to be equivalent to the battery life of the Pandora 1. So that's the bare minimum for me.

But since battery life is obviously one of the great strengths of the Pandora 1, why not go further and improve it? Maybe we can use newer battery technology like nanowire batteries, which could potentially have a 10-fold increase in capacity and charging times measured in minutes, not hours. And as I said before, with big.LITTLE the cpu power consumption under low loads is nearly zero, and with AMOLED, the display power consumption should improve (at least when most pixels are dark). So I don't see why we shouldn't aim for something like 10-20-50-150 hours of battery life, with a charge time of 15 minutes.
 
Honestly, i'd be looking for an improvement in battery life, if that's at all possible. It's a major selling point to me
 
and the peak performance will increase the usage a lot.
Not sure how you reached that conclusion, really. 

All components should be at least better in terms of power consumption than for the Pandora 1 hardware. Modern phones last longer than my phone two years ago. Usage duration is not going DOWN on the market, it's going back UP. Pandora 2 should be at least at the same level as the Pandora 1 in terms of autonomy. 
 
and the peak performance will increase the usage a lot.
Not sure how you reached that conclusion, really. 

All components should be at least better in terms of power consumption than for the Pandora 1 hardware. Modern phones last longer than my phone two years ago. Usage duration is not going DOWN on the market, it's going back UP. Pandora 2 should be at least at the same level as the Pandora 1 in terms of autonomy. 
Peak power consumption will probably be higher than on the P1: I think it's safe to assume that even though the perf/W of the CPU/GPU will probably be slightly better than that of the P1, their top performance will be much higher than that of the P1. So on low loads it will consume less power than the P1, and on high loads it will consume more power. The same with the screen: if we're going for AMOLED and a bigger screen, then in the best case power consumption will be better (e.g. a mostly dark screen causes OLED to use much less power, so that more than compensates for the larger screen area), but int the worst/peak case, power consumption will be much higher (for a fully white screen, OLED uses 2 or 3 times as much power as LCD, and if the screen area is larger, the total peak power consumption of the screen could be maybe 5 times that of the P1 screen).

Same with anything else (wifi, sdxc, usb): perf/W will most likely slightly improve, but raw perf will most likely improve more. So for instance the P2 will use less power than the P1 to download a file over wifi at 300KB/s close to the access point, but it might still need significantly more power than that to do the transfer at 5MB/s far away from the AP where the P1 can't even establish a connection.

I don't worry much about peak power consumption, I'm mostly interested in the low load and average load case.
 
That sounds like very bad news for gaming on OLED. Couple that with OLEDs lower usable lifetime and you have a good case for staying with LCD.

(for a fully white screen, OLED uses 2 or 3 times as much power as LCD, and if the screen area is larger, the total peak power consumption of the screen could be maybe 5 times that of the P1 screen
 
You play games where the screen is mostly white?

An entirely black OLED screen will use almost no power at all
 
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That sounds like very bad news for gaming on OLED. Couple that with OLEDs lower usable lifetime and you have a good case for staying with LCD.

(for a fully white screen, OLED uses 2 or 3 times as much power as LCD, and if the screen area is larger, the total peak power consumption of the screen could be maybe 5 times that of the P1 screen
Don't worry, your Pandora 2 will be seriously obsolete long before your OLED screen dies. 

The OLED longevity issue is not a myth, but I have had a OLED screen for 3 years and it is still in perfect state. I don't worry about that. 
 
 The same with the screen: if we're going for AMOLED and a bigger screen, then in the best case power consumption will be better (e.g. a mostly dark screen causes OLED to use much less power, so that more than compensates for the larger screen area), but int the worst/peak case, power consumption will be much higher (for a fully white screen, OLED uses 2 or 3 times as much power as LCD, and if the screen area is larger, the total peak power consumption of the screen could be maybe 5 times that of the P1 screen).
While you are right about the 2 to 3 times higher consumption to display white screens... you are painting an overly negative image. For gaming, for example, most of the cases you will not be facing a white screen, and consumption is lower for all non-office applications. 

Power consumption


While an OLED will consume around 40% of the power of an LCD displaying an image which is primarily black, for the majority of images it will consume 60–80% of the power of an LCD: however it can use over three times as much power to display an image with a white background such as a document or website.[78] This can lead to reduced real-world battery life in mobile devices when white backgrounds are used.

So if you are gaming with an OLED screen, you should see better autonomy. 

Since most Pandora users are doing many things with their Pandora, I dont think you will see much difference in the end just because of the screen turning OLED. It should balance things out between gains and loss over multiple usages.

On top of that, I am not sure how much the extra touch screen consumes on the current Pandora but that's something you have to remove when you move to AMOLED, since touch screen is de facto integrated. It may not be much but it's a constant power drain that never goes up or down.
 
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A CortexA15 dualcore under full load can suck the current Pandora battery dry in under two hours. And that is without taking any other components into account (like screen, Wifi, etc.)


However, at same performance as the current Pandora, it uses less power.


I think with using the same power, it should have about 2 times as much processing power as the Pandora.


It's not possible to keep the same battery time under full load with the same battery size, but battery time would still be better under normal usage.
 
How much heat can they dissipate when poorly ventilated?

The current pandora gets warm quite easily if working hard while in a case or pocket - won't overheating be a problem with newer/more powerful SOCs?
 
Armchair experts Blinky and ekianjo seem to be completely lost in fairy land.... and WB seems to have super nano batteries which don't exist yet :)

Evil, It seems that you and your team have a challenge on your hands  B)

edit: I'm no "expert" and as I said, I'm looking for numbers but It is safe to say.... the new Pandora will drop the battery life (Id love for this to be incorrect).. so Id start buying those tissues in bulk if you care
 
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