How Is The Battery Life Indicator Going To Be?


fusion_power said:
rasczak said:
Red led static: really low battery, search for a charger, please. (15%-5%)
Red led flashing: SOS, my battery is gonna die!!! (5%)
Yes, this is the way I also want to see the LED's working. :) Red LED starts glowing when the Battery becomes empty and the blinking starts when it gets really serious, so the last 5-Minutes-reserve or so. Blinking is always a good indicator for Danger.


That'd be my preference as well, simple and clear, universal.
 
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MWeston said:
Unlike the PSP which seems to have some electronics in the battery pack that might monitor the level and report battery life, Pandora will manage this in software only. There is quite the collection of parts in a PSP battery. Does it do it this way or am I wrong? My PSP coding experience was a "Hello World!" app a few years ago. :) I've never examined code that determines the percentage.
The PSP's battery is where Pandora lives ;)

Plus it contains the battery safety circuit, memory to (so I've been told) store the manufacturing date of the battery, serial number, and the capacity of the battery.
 
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Nova said:
Lithium batteries die much faster if they go from full charge to empty over and over.

Citation




Yes, that's true as I know. That's why I made an "orange state", because it's not a problem for normal use, but you will know it's time to connect it to charger if you can.

I'm sure buying a new battery and change it won't be difficult, but it's better don't need to do it.

"Mejor prevenir que curar", it is said in my country at this times. Sorry but I can't do a good translation, may be another user...
 
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MWeston said:
The battery starts at about 4.2V fully charged and crapped out at some point just below 3.5V I think. I took a voltmeter to it about once an hour and with the 8.5 hour battery life I got, it dropped close to 0.1V per hour. Assuming it stays that way until the battery has been charged/discharged many, many times, it is a fairly linear scale. I was actually surprised to see this result, but it works out so well for what we want to do here if it is consistent for every cell

That sounds kind of weird. All the Li-ion cells I've seen drop quickly to 3.7 V and stay mostly flat before a rapid drop at the end of its life. Though... I've only looked at larger cells that one might incorporate in electric vehicle designs.

A coulomb counter would be more accurate for determining the remaining charge, but if the discharge curve really is almost linear, that certainly is convenient... :)
 
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Tinnus said:
How about that:

100% - green
"0%" - red
between: fade between red and green with oranges in the middle :)
How about 100%-31% -Green and 30%-0% Red

Then, charging can be a cycle that quickly fades from red to green (with oranges) over and over again.

-God Ginrai
 
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rasczak said:
"Mejor prevenir que curar", it is said in my country at this times. Sorry but I can't do a good translation, may be another user...
I hardly know any spanish so correct me if im wrong but i think that would translate into:
It's better to prevent than to cure

On topic: I like the idea of slowly fading from green to red, that way you would instantly know (after a while of getting used to ofc) in what state the battery is
 
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rasczak said:
What about...

Green led flashing: charging.
Green led static: High battery. (100-40%)
Orange light: medium battery, but not fear. (40%-15%)
Red led static: really low battery, search for a charger, please. (15%-5%)
Red led flashing: SOS, my battery is gonna die!!! (5%)

It could be combined with fading cicles MWeston said... OMG I love little leds working... Hahahaha.
My opinion:

If power on then green on full charge, fade through orange to red as battery go low to 10% (or other user defined value). Under 10% of battery red blinking!
If sleeping then green flashing, but short flash after while (1/5 vs 4/5 sec, or so).
If charging then orange flashing if off, and green/orange changing when power on.
 
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If the leds are software controlled. Then we're just going to have to have a really annoying app that will flash them in time with the music.... I remember an old winamp plugin that did that for the num/caps/scroll lock leds. =D
 
MagicPants said:
MWeston said:
Unlike the PSP which seems to have some electronics in the battery pack that might monitor the level and report battery life, Pandora will manage this in software only.

So is the Pandora going to do this solely based on time?


Errm, nope. The software polls the voltage from the battery and then knows how much there's still left.
For PSP, the battery TELLS the PSP how much there is left. This is useful if you have different types of batteries available.

If you use a foreign battery for the Pandora, you might need to calibrate it first so that the Pandora knows when the battery level is critical (it's already setup for the battery you get when buying your Pandora).
For the PSP, this is not necessary.
 
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proflogic said:
MWeston said:
The battery starts at about 4.2V fully charged and crapped out at some point just below 3.5V I think. I took a voltmeter to it about once an hour and with the 8.5 hour battery life I got, it dropped close to 0.1V per hour. Assuming it stays that way until the battery has been charged/discharged many, many times, it is a fairly linear scale. I was actually surprised to see this result, but it works out so well for what we want to do here if it is consistent for every cell

That sounds kind of weird. All the Li-ion cells I've seen drop quickly to 3.7 V and stay mostly flat before a rapid drop at the end of its life. Though... I've only looked at larger cells that one might incorporate in electric vehicle designs.

A coulomb counter would be more accurate for determining the remaining charge, but if the discharge curve really is almost linear, that certainly is convenient... :)

None of the li-ion batteries I've ever dealt with have a linear discharge. It's usually almost linear, dropping very little until it hits the "knee" of the curve, at which point the voltage drops sharply. From what MWeston is saying, sounds like that's exactly what happens, with 3.5V being the cutoff. Optimal operating voltage is probably around 3.8 volts.
Li-ion don't like to be overly discharged. Hitting 3.5V often will cause severe damage and can reduce battery life drastically.
Even if you take care of it, over time the battery will lose it's chargeability, but it shouldn't affect the max and min voltages. If you label 4.2V as 100% and 3.5V as 0%, and just do a linear scale between the two, that should be close enough. For best results, keep it stored at around 40%, and don't let it fall below 20%.
 
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WizardStan said:
proflogic said:
MWeston said:
The battery starts at about 4.2V fully charged and crapped out at some point just below 3.5V I think. I took a voltmeter to it about once an hour and with the 8.5 hour battery life I got, it dropped close to 0.1V per hour. Assuming it stays that way until the battery has been charged/discharged many, many times, it is a fairly linear scale. I was actually surprised to see this result, but it works out so well for what we want to do here if it is consistent for every cell

That sounds kind of weird. All the Li-ion cells I've seen drop quickly to 3.7 V and stay mostly flat before a rapid drop at the end of its life. Though... I've only looked at larger cells that one might incorporate in electric vehicle designs.

A coulomb counter would be more accurate for determining the remaining charge, but if the discharge curve really is almost linear, that certainly is convenient... :)

None of the li-ion batteries I've ever dealt with have a linear discharge. It's usually almost linear, dropping very little until it hits the "knee" of the curve, at which point the voltage drops sharply. From what MWeston is saying, sounds like that's exactly what happens, with 3.5V being the cutoff. Optimal operating voltage is probably around 3.8 volts.
Li-ion don't like to be overly discharged. Hitting 3.5V often will cause severe damage and can reduce battery life drastically.
Even if you take care of it, over time the battery will lose it's chargeability, but it shouldn't affect the max and min voltages. If you label 4.2V as 100% and 3.5V as 0%, and just do a linear scale between the two, that should be close enough. For best results, keep it stored at around 40%, and don't let it fall below 20%.
and store it somewhere cool, warm temperatures tend to damage the battery.
 
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It wouldn't surprise me if fairly close to release, someone releases an app that stress tests the pandora to death, polling the battery for voltage every 10 minutes or so and writing the result to SD each time. Assuming the SD wouldn't die if it were to lose power during a write (which was definitely an option for SMCs, but I believe isn't so bad for SDs) this would effectively let your customise your battery meter to your particular battery.

Just a thought...
 
What is clear about having multiple states (fading, flash, etc)? Either it's time to charge the battery, or it isn't. A gradual fade might not be noticed, and it's ambiguous because you have to guess how red it is. Blinking...can't believe I even have to say how terrible it is.

I'm trying to understand the allure of multiple levels of warnings, but I really can't. Again, if you didn't charge it at 15%, why do you want another warning for 5%? At that point it's going to die, and if you lost your work, it's not like it was a surprise.

But hopefully it'll be easy to tweak so that people that want something fancy can go to town. I'm with mechanizeddeath...green=good, red=bad, yellow=charging.
 
rokdcasbah said:
I'm trying to understand the allure of multiple levels of warnings, but I really can't. Again, if you didn't charge it at 15%, why do you want another warning for 5%? At that point it's going to die, and if you lost your work, it's not like it was a surprise.

Um its pretty simple. If you're on a plane or a train next to no power point and the Orange light comes on then you know you can keep playing, but better not start any long missions! If it's flashing red then it's time to quickly finish what you're doing (create a save state, maybe) and power off.

If you're near a power point/usb point then plug it in as soon as it goes orange.
 
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Pleng said:
Um its pretty simple. If you're on a plane or a train next to no power point and the Orange light comes on then you know you can keep playing, but better not start any long missions! If it's flashing red then it's time to quickly finish what you're doing (create a save state, maybe) and power off.

If you're near a power point/usb point then plug it in as soon as it goes orange.
If the orange light comes on, you know you've only got so much time left. What benefit does a flashing red add?
When my DS light turns red, I know I've got 30 minutes of play time left. It's not adding any information to tell me I've only got 5 minutes left after 25 minutes.
The only really legit reason I can imagine for an extra, flashing alert is to say "Power is so low, there might not be enough to write to the SD card!" at which point it's too late to save safely.
 
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WizardStan said:
If the orange light comes on, you know you've only got so much time left. What benefit does a flashing red add?
When my DS light turns red, I know I've got 30 minutes of play time left. It's not adding any information to tell me I've only got 5 minutes left after 25 minutes.
OK, maybe you, but not me. When orange LED lit, I not draw phone to look what time is and start 25 minutes count down. If I can't reach power plug, I like to be inform about critical state to safely turn off a device.

edit: I don't using watches, because phone has time on display so I can get it if I really need know what time is.
 
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Ok, how about this then: the warning light comes on at 10%, when there's about 30 minutes of play time left. The warning light is there to tell you not that you've got 30 minutes of play time, but that if you keep playing you will damage your battery. Draining out the battery is very bad for lithium ion. The 30 minute mark (or wherever it happens to lie) is where you should be saving and shutting it off. Yeah, you could keep playing another 20-30 minutes, but that will damage your battery. Just save and shut it off.
 
WizardStan: There always is group that doesn't care about battery wellness. I occasionally do this too. I usually recharge my phone every day, but sometime I don't have chance to recharge immediately, so I using it even if less than 30% of battery capacity.

Yes, there can be option as PDA usually has - indicate low state and after crossing a line - emergency sleep to save power for memory and no awake on unless recharge.
 
Point is, I'm trying to give logical reasons why multiple warnings should not be given. It's mostly just for debates sake at this time, since it won't really have any effect on me (so long as warning is at 10-20%) but that doesn't mean we can't discuss it.
Truth be told, I think I've lost my train of thought on this now.
 
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