Battery Drain

[Galaxis]

Don't know a whole lot about the Pandora, so not much fodder for speculation... But if the battery drains only when it's connected, that suggests that the device is somehow using power even in off state - not that the battery is faulty?

 

[Tor]

These kind of devices will drain a little even when off, but it should be _very_ little. I'm not sure about the Pandora, but my Nokia N800 can power itself on by a programmed alarm. That would only work if there's power to a little part of the circuitry.


I think most phones drain a little as well. At least there's a huge difference between all the phones I have and one of my GPS units: If I leave the phones in a drawer, charged and off, the battery will still drain and after a month this is quite noticable. The little GPS unit, on the other hand, is absolutely off when off and it seems to last forever (there's a built-in charge tester which I check every few months).

 

[levi]

The Pandora has two 'off' modes - 'low power' which I understand as some sort of standby mode where it can still wake on alarm etc, and 'off' which should be completely off - the Pandora can't even charge when 'off'. Based on tsh's stats, 'low power' would eat more than 10% overnight as it currently stands, so I'm assuming it really is 'off'. Maybe there's some small things like keeping the clock battery topped up when off, but that should amount to minute current drains, so it ought to last for months in that state.

 

[tsh]

The Pandora has two 'off' modes - 'low power' which I understand as some sort of standby mode where it can still wake on alarm etc,

Today, low power is not really a standby state, it is just a state where a few things are switched off.

• WiFi Off
  
• BlueTooth Off
  
• Display blanked
  
• Backlight off
  

Also, the CPU clock speed is lowered (this has varied a bit with different hot fixes, 125 MHz is a good setting for now, since that allows the lowest voltage setting to be selected too).


In this state, the OS is still running normally (although it might be unable to keep up with it's regular housekeeping tasks). There is scope for turning more off, but it's not been done yet. If you have an android device, we're probably at the 'wake lock' state at the moment, which would be an app refusing to be suspended, even though the phone looks like it is off.


In the really off state, you'd need to leave a pandora alone for at least a week to get a good idea of the battery drain (and then I'm not sure if the battery gauge would still be accurate).

 

[Twiitcher]

My pandora is losing 1% power in the really off state, low power analysis is totally off-topic for my issue.

 

[tsh]

My pandora is losing 1% power in the really off state, low power analysis is totally off-topic for my issue.

I thought you were saying that in 'off' mode, it was loosing 30% overnight...

 

[Twiitcher]

I thought you were saying that in 'off' mode, it was loosing 30% overnight...

My first post stated that however all tests from that point on, more closely monitored show 1% loss per hour, all tests until now were only completely off, so initial observation was inaccuurate,probably not completely off.


Just tested overnight in low power - 5% per hour loss in low power mode...again 1% power loss when shut down and completely off. The issue as I've stated repeatedly is battery drain of 1% per hour when the unit is "completely off". Last night was the first test I performed in low power mode.(except the initial test which was probably not really shut down completely).


So to summarize, the issue I have is 1% battery drain per hour with unit completely off.

 

[WizardStan]

yeah, 5% per hour in low power mode seems about right.


Do you ever notice problems with your clock when it's been completely off for several hours? Someone else reported their clock wouldn't keep time, and I'm kinda working on a theory.

 

[Twiitcher]

yeah, 5% per hour in low power mode seems about right.


Do you ever notice problems with your clock when it's been completely off for several hours? Someone else reported their clock wouldn't keep time, and I'm kinda working on a theory.

The clock keeps accurate timE for me in all modes. It's been on full, in low power mode and completely off and is maintaining accurate time through all modes.

 

[WizardStan]

well that blows that theory

 

[tsh]

So to summarize, the issue I have is 1% battery drain per hour with unit completely off.

I think if this is a problem for you, you should contact your distributor directly and ask for an RMA.

 

[Korlithiel]

So I figure it's appropriate for me to note that I'm having a similar issue. I tend to plug in my Pandora before sleep and wake with it showing that it's not charging and the battery isn't full.


Edit: Monday night I ran the battery down to about 32% before I plugged it in and called it a night. Tuesday morning it was charged to only 85%. I'm thinking it's just that I'm not getting accurate readings on the charge level, but really don't know.


I don't recall the charge level last night but I turned it off and forgot to plug it in to find this morning the system had run the battery out overnight. Guess when I can afford to ship it in over the dying LCD cable I'll note this issue too.


Edited again: Interesting note, I put it on the charger this morning I kept checking until it read 100% charge but the light was still on. Pulled it from the charger and it read 92% after a couple seconds. So I'm guessing the system isn't getting a good read from the battery, going to try reseating it again to see if things improve.

 

[Twiitcher]

I think if this is a problem for you, you should contact your distributor directly and ask for an RMA.

As mentioned in an earlier post in the thread, I have PM'd Craig. I'm just patiently waiting for a response. I understand he's a busy man so I'm refraining from being a pest about it.

 

[Prometheus]

I think what's meant there is sending an e-mail, rather than a PM. I'm guessing you bought from Craig, so in that case the address to use (which I have no doubt you already know, but for the sake of future searchers and suchlike, I'm going to mention anyway) would be openpandorasales@gmail.com - that would be the quickest way to get it dealt with.

 

[tsh]

I think what's meant there is sending an e-mail, rather than a PM. I'm guessing you bought from Craig, so in that case the address to use (which I have no doubt you already know, but for the sake of future searchers and suchlike, I'm going to mention anyway) would be openpandorasales@gmail.com - that would be the quickest way to get it dealt with.

Yes, you wouldn't normally expect the guy running the company to handle RMA, you would contact the customer support team. In order to allow the team to have a chance to look at the hardware, you can attach a note to it which gives explicit details about the problem - but I expect it will go on a pile of 'broken' units which will not be a priority for debug (there are likely other issues such as the LCD cable which are still high risk). If this unit is going to be debugged, it needs to get back to MWeston - there are not many people who know enough about the design in enough detail.

 

[Tor]

Edited again: Interesting note, I put it on the charger this morning I kept checking until it read 100% charge but the light was still on. Pulled it from the charger and it read 92% after a couple seconds. So I'm guessing the system isn't getting a good read from the battery, going to try reseating it again to see if things improve.

li-ion batteries are not fully charged just because it reads 100% while charging. 100% just means that it's reached whatever voltage defined as 100%, for example 4.20 volts. To fully charge it you need to continue charging it with, say, 4.24 volts until it reaches _that_ voltage and the charging current drops to zero (when you then remove the charger it'll drop to approx. 4.20 volts (in this example)). That'll take a bit more time. It's quick to go to 100%, you can usually get there in a fraction of the time it takes to actually charge the battery to full. Wait until the charging light goes off (I assume it'll go off, but I don't have my Pandora yet so I'm not sure. On my Palm the light doesn't go off ever, so I either have to wait long enough until sure, or use FileZ to check that the voltage has reached 4.24. On my other devices there's an indicator (light or icon) which turns off.)

 

[WizardStan]

The light is not supposed to go off. Once it reaches full charge (not 100%, but when the battery stops accepting a charge), the charging circuit reduces it to a trickle charge, limiting the current into the battery to exactly what is coming out of it.


Some people have mentioned that their Pandora does stop charging, and the light turns off, when it reaches 100%. I *just* experienced this myself this morning. The light was off and it was sitting at 100%. Since then I've drained and recharged several percent a couple of times and can't get it to stop charging like that again.


So in general, the charge light should remain on even after it's reached 100%, but there seems to be some kind of weird and random thing that occasionally does stop the charging.


edit: actually, that "indicator" idea might be a good suggestion. Once it's reached full charge and dropped into trickle charge, maybe start blinking the charge LED instead of solid on or something. I'll have me a think on that.

 

[Prometheus]

^ Stan, the stopping-at-100% thing has happened to me twice with my Pandora (and one of those times it had actually run itself down a bit before I noticed it had happened). If you're curious, I noticed that it seems to depend on how hot the unit has gotten (the time when it ran down a bit, it wouldn't start charging back up again until it had sufficiently cooled down) - the two times it happened to me, I had it in a bag whilst it was plugged in, and it got quite warm. If it's outside the bag it absolutely doesn't happen.

 

[WizardStan]

Hmmm, sounds like experiment time.


FOR SCIENCE!

 

[Tor]

edit: actually, that "indicator" idea might be a good suggestion. Once it's reached full charge and dropped into trickle charge, maybe start blinking the charge LED instead of solid on or something. I'll have me a think on that.

I think it would be a good idea to have a clear indication that the battery is fully charged. Aren't the LEDs capable of changing colour? The Nokia N900 charges with a slowly blinking yellow light, when finished it changes to stable green (which switches off when you remove the charger cable).