In my wanderings about the forum for the last many months I've seen complaints about battery life, and answers about problems with batteries. Some of this has meshed in my head and I believe I can explain some of the seemingly 'bad' behavior we see reported (which happens at the end of this very long post). To begin with, below are some points that *I* accept as fact about batteries and charging, and why I accept them. 1) The charger turns off so the battery won't over charge. Yeah, we've all seen this. You plug in the phone before you go to bed, in the morning you unplug the phone, but you KNOW it didn't take all night to charge. Somewhere along the way the charger turned off. Now there is some debate on exactly where the brains of this operation live. Some folks say it's the charger, some folks say it's the phone, some folks say it's the battery itself. *I* am of the opinion that it's the battery itself, and here's why. I DON'T believe it's the charger, I can't believe that $3 Ebay chargers contain that many smarts, but yet they work properly (usually). That puts it in either the phone or the battery. Now let's go to EBay and buy one of those cheap (excuse me, inexpensive) charger/battery combos. You know, the kind where you can plug the battery directly into the charger. Now I still don't believe the charger has 'smarts', but yet the battery doesn't overcharge, to ME that indicates that the battery controls the on/off state of charge for the simple fact that the phone has been taken out of the loop completely. However, because we're all accustomed to seeing 'the charger is off' type terminology I'll use it here, but I don't really believe that's what's happening. 2) The charge light turns green before the battery is 100% charged I've seen several reports of this. There is debate on when exactly the light goes green, some say 90% some say 95% - there is general agreement on somewhere in the 90's, for our purposes we'll use 95% as the threshold. I believe this is true because of the battery charge cycles. Battery life is measured in charge/discharge cycles rather than age (of course age has an effect too). Batteries are good for X number of cycles, after that they start to degrade. For the sake of ease we're told that the useful life of a battery is about a year, but what we're really being told is it takes about a year to go through the number of charge/discharge cycles that will start to wear out a battery. I believe the light goes green to indicate 'cycle complete OK to remove charger' rather than '100% charged'. I think what the engineers are trying to tell us is that the battery is sufficiently charged that removing it from the charger won't 'waste' a cycle. 3) The phone always draws power from the battery, even when plugged in. This is actually a big one and kind of the thing that holds everything else together. We've all seen the threads about how "my battery gets really hot when plugged in and navigating at the same time". To me that indicates the battery is doing double duty - it's being both charged and discharged at the same time. If the battery were being bypassed and the phone drawing it's power directly from the charger then the battery would actually be cool. And another simpler test, remove the battery from your phone, plug in the charger and see if the phone will turn on (it won't - or at least mine doesn't). The reason the phone always pulls from the battery is so that it receives a constant amount of 'juice', which the electronics really like. Imagine the havoc inside the phone if it bypassed the battery to pull directly from the charger. You're at home and the phone plugged in, then somebody turns on the entertainment center with it's 200 inch big screen TV, 15 speaker surround sound system, blueray, dvd and vcr (for old times sake) players - the lights dim in the house. The phone would NOT like that (and we haven't even touched on the inconsistent current that goes to a power adapter in a car), to prevent a problem the phone draws power from the battery - only and always. 4) When plugged in, after fully charging the charger will not turn back on until the battery has discharged to a set threshold. Another biggie. We already know that the phone always pulls from the battery (have you tried turning on your phone while plugged in but without a battery yet?). And we know that batteries have finite number of cycles until they start to degrade. For these reasons I believe that the charger won't turn back on until the battery reaches a certain level of discharge - in an effort to limit the number of charge cycles the battery goes through. I've seen numbers from 75% to 85% as being the point at which the charger turns back on - for purposes of discussion I'm going to use 85% as the threshold (though I'd have no problem believing it's actually lower). Because I've never seen the light go BACK to orange while on the charger, I also believe the light stays green as long as the charger is plugged in - rather than switching back to orange at 85% charge when the charger comes back on. Now we get to real world examples. Yesterday I was messing with my phone a lot and because of that I had to swap batteries late in the day. Therefore when I plugged it in last night it was showing 80% charge. This morning when unplugged it only showed 95% charge. Some folks would say that the battery didn't charge overnight and that there's a problem. *I* say that the battery was fully charged early - lets say at midnight - the charger shut off and that the phone ran on battery power all the rest of the night. So from midnight until 6:30 when I unplugged it, 5% of the battery was used. Because it didn't get below the 85% threshold the charger never came back on to bring it back up to 100%. And more extreme, we've all seen the "My battery/this phone is crap - it used 20% in 30 minutes" threads (but then it turns out the remaining 80% lasts a reasonable amount of time). *I* think that what really happens is that the phone was charged early in the evening and ran all night on battery. Meanwhile this person has 500 friends on Facebook who are all writing on the wall and sending Farmtown messages, also they follow 45 people on Twitter and pull email every 15 minutes and update weather every half hour and pull news headlines and and and... In the morning when they unplugged the phone was at (for example) 87% charge. They fire up Pandora for 45 minutes and check the weather, thereby using 7% of charge. Suddenly the phone is at 80% charge but they've done 'nothing'. In reality the phone has been off charge and working fairly hard for 6 or 7 hours. I also suspect (suspicion only) that it sometimes takes a few minutes for the battery meter to drop down to (the example of) 87% when first unplugged. I see this in reverse in my car. My car has a digital dash with little 'blips' for a fuel gauge - when I fill it with gas it takes a good minute or so for the fuel gauge to work it's way up a blip a a time to 'full'. It wouldn't surprise me if the battery gauge on our phones works the same way - once unplugged it takes it a few minutes to display the actual battery charge, working it's way down from 'full'. So if the person did glance at his meter right when he unplugged the phone it may still show 100% - or something close. There you go then, that's my take on it all. If you read this whole thing, kudos to you!