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Downgrade to 902 - No app or data loss
- Thread starter SamuriHL
- Start date
sargentmajord
Silver Member
SamuriHL said:Check those MD5's people.
Blasphemy
Sent from my 1.404 ghz 3605 quadrant score ICS .246 DROID BIONIC
Actually, it's not about the current rating. It's about the voltage regulation. At work we played around with a charger that did weird things to my phone just like you said. It would register weird screen presses when I'd press someplace else, etc. The issue is that some chargers don't regulate voltage very well. Using an oscilloscope we found large voltage fluctuations in what should be a DC output. While small in nature, they were significant for what typical acceptable voltage regulation is. We added a circuit between the output of our charger and the input of the phone to help regulate the output better, and the problem went away. Based on that information, we are pretty sure the problem is the voltage oscillations and not the current.
But, I will say this. I'm a little hesitant to plug MY phone into a 2.1A charger port on a daily basis(it was the monoprice wall charger I linked to). I did do it at a friend's house and it worked fine and performed well with no bizarre behavior. I just get a "weird" feeling that it's probably not supposed to take that much power at once
.Of course, I haven't seen a ton of posts from people claiming 2.1A chargers fried their phones. Not to mention that if the charger broke your phone as a consumer you likely don't have the skills or equipment to actually put the finger at the charger.
So /shrug. To each their own with high current chargers I guess.
This totally explains what i have experienced. I am certainly learning a lot from this thread.
I always assumed phones current limited them selves to a safe level based on the battery spec and the integrated circuit responsible for managing the charge. I thought that a given resistance or voltage on the data pins signals a charge port at up to a given current. I also thought that the device would limit current to a specified level. Very surprised to learn our phones will pull more than 1A.
Kind of scary if it ever puts more than 1x the capacity i.e. charges at more than 1C as these batteries are probably not rated for that. This would result in a bad battery in a very small number of charge cycles. Charging at a lower current means your battery will last more cycles.
I wonder how much current my poor droid was pulling from the computer ps i was using. I would have thought it would never use more than 1A to 1.5A at most. The 5V rail it was connected to could push out 15A with out even having the cooling fan turn on. I dont think it would have pulled out of spec current just because the charger can supply it.
Guess I will have to look into this further.
BePrepared
Member
This whole miserable experience with the Bionic and ICS has just reached the point of absurdity. I went to 232, thinking that the OTA would be out in just a couple of weeks. Enough is enough. I went to 246 tonight. No going back now.
Thanks again Samuri for all of the time that you've devoted to this ridiculous cause.
Thanks again Samuri for all of the time that you've devoted to this ridiculous cause.
Your USB ports on your computer are typically 400mA or so. A few motherboards have a special feature designed to charge devices at an "accelerated" rate, which I think was 600mA or 800mA. Overall, the computer seems to be the slowest charger out there.
Overall, if you try to put a huge amount of current into the battery the protective circuit I talked about earlier will not allow you to charge it that fast. If it can't regulate the charging rate, it'll blow the fuse and your battery will miraculously stop working suddenly. Also, the faster you charge your battery the hotter it will get. I[SUP]2[/SUP]R losses reign supreme. As the battery gets hotter the less current that will flow through it, and the less "complete" of a charge you get. As the battery cools you will be able to put a few more % power into the battery. For most people, you won't be able to tell me you are "missing" 5% of your battery. I don't think the indicator will tell you that you are only 95% charged and then slow go to 100% as the battery cools if left on the charger. It's a physical characteristic of the battery and the only "fix" is to not heat up your battery.
I know the Motorola chargers put out 1300mA since I saw my Bionic pull that much from my car charger. Apparently Motorola thinks that 1300mA is still safe since that's what their product will do, right? An almost dead battery will have a much higher current draw than an almost full battery. As the battery nears full capacity the amount of time it takes to get the next 1% charged increases.
Apple got in trouble for using these battery characteristics to virtually lie to customers. (I forget the numbers so I'll make some up) Apple claimed their iSomething had a 2000mAh battery and it would charge fully in an amazing 1 hour. The catch... If you let it charge for just one hour you'd only get 80% of a full charge. It actually took the typical 2 hours to get the full charge. I believe Apple lost a lawsuit over this because they were trying to claim a larger battery capacity than their competitors AND claim they could out-charge their competitors. The truth was their battery wasn't really superior to competitor products. The industry standard is to post your total battery capacity and the time to fully charge a dead battery. You can't market a battery as full capacity and then provide charging times for a partial charge. If you could then a company could easily say my Android device has a 2000mAh battery and can charge fully in 5 minutes even if you really only get 10% of a charge. I would have to market the battery as a 200mAh to claim the 5 minute charge. Who in their right mind would buy a device with a 200mAh battery? Some companies also provide numbers for 75-80% for slightly better comparison of the typical charging rate. Getting the last 20% charged on your battery usually takes about the same amount of time as getting the first 80%.
My typical charger is a computer's USB port. It's slow, but typically I leave it plugged in for a long period of time(work, sleeping, etc). Also slow charges don't heat up your battery like the rapid/fast chargers do. Heat is the enemy for batteries. Leaving one in your car on a summer day can really do a number on them.