Hey guys!
I have been the proud owner of the Razr Maxx for a little under a week and I have been elated about it so far. Though I have been underwhelmed with the battery so far. The first two days I have had an average battery life of 8 hours with moderate use (I can't use it much during the day because of work) until I upgraded to ICS and did a factory reset. Also I set up some of my smartactions to shut off background syncing when I don't use it, etc. Also I adjusted my display to be less consuming. I also tried draining the battery to around 15-10% and charge it over night (with the phone still on). Now I can probably squeeze 12-14 hours out of the phone with light-moderate use (again for eight hours I can only really text and occasionaly check (FB). Should I keep up with this drain and charge calibration or should my phone be off when I charge?
Note:
The reason I suspect a battery tracker calibration as opposed to a dead battery is I downloaded a battery widget that also tells me how many mV I left in the battery along with percentage and this is the pattern roughly:
4200 mV: 100%
4100-4000 mV: 90%
3800-3900 mV: 80%
And so forth until I hit around 3400-3500 mV which will read 10-15% battery.
Isn't 3400 mV alot of juice just to be at 10%?!
Really, 3,400mV isn't all that low for a 10% battery level. First you have to be sure you're actually at 10% before you even begin to question the 3,400mV reading. Unless you are using an accurate battery tool with a 1% increment AND the meter for the battery must be calibrated to the battery accurately.
Then, you need to understand the typical discharge curve of a Lithium Ion (and more specifically for us a Lithium Ion Polymer Pouch Pack) battery. It's quite a bit different than other types of batteries, which is both good and bad. Good because computerized electronics need a very steady voltage that is within a rather tight range to operate. Too low, the computerized electronics will start acting strangely, throwing errors, force closes, corrupting data, and completely freezing. The same happens in reverse if the voltage is too high, mainly due to the excess heat that voltages which are too high will cause, and even worse, in high voltages situations permanent damage can occur.
What makes LIPO batteries uniquely well suited for our devices is that the voltages for these batteries, when operating in the safe range and with the limits in charging and discharging are set to levels that provide the best blend of runtime and battery life will be relatively flat for the greatest part of the discharge cycle. See the image below for a representation.
View attachment 53106
Now before I go on, a disclosure. This is a representation of a battery that is being discharged at a rate that is 6 times the battery's capacity, or in other words, if the battery can supply 1000mAh, this battery is being asked to put out 6,000mAh, so of course, it won't last 1 hour. Here you see the battery holding out for about 9 minutes. Could you imagine if our phones only had a 9 minute runtime? :blink:
Anyway, we're only using this chart to show one thing...how the voltages drop at different rates during different parts of the discharge period. You'll notice that the voltage drops off rather quickly during the first 10% of the discharge cycle here (100% to 90%), or from about 3.85V to about 3.675V. Then it drops from 3.675V to 3.5V in the next 10% (90% to 80%) Then you'll notice it drops off very gradually from there to about the end of the 7th minute (80% to 30% - or HALF the entire battery's power cycle), from about 3.5V to about 3.4V over a range of 50%. Then it starts to look like the same roll-off rate for the next 10% (30% to 20%) or so that it did from 90% to 80%, and then in the next 10% (20% to 10%) or so it drops rapidly, and in the last 10% (10% to 0%), it's in a near free-fall.
Even though this chart is for a far more aggressive discharge cycle than our phones will EVER come across, it is still a good representation of how our discharge cycle looks, although you would have to stretch this about 60 to 120 times wider (9 to 18 hours).
This chart also shows something I've tried to impress on everyone. The battery suffers stress at the top of the charge curve and at the bottom, or in other words where the curve is at its greatest rate of change. On the other hand, the battery is quite happy to cruise along with very little stress during the middle of the discharge curve, that 50% portion between about 80% and 30%. That is the sweet spot for the battery where if it's kept running in that range, or charged to 80% and used to 30% religiously, it will provide the longest lifespan, in terms of how long it will last over time, years or number of charge cycles.
Lastly, you'll notice a dotted red line through the bottom of the chart. That's the critical voltage level where the battery should really be charged. Truth is these "minutes" across the bottom shouldn't really be used interchangeably with percentages in the range of 100% to 0%, but instead the 0 through 9 should be divided into 10 sections, so that at minute 9, when the voltage hits 3V, that should be considered DROP DEAD voltage and 0% or less. This is WHY I tell EVERYONE, DON'T discharge to 0%. It's a very short trip from 3V at 0% to 2.5V - 2.7v at -3% or so, AND where the battery will shut down permanently and never take a charge again.
One final afterthought. If you DO happen to discharge to 0%, and if your meter is properly calibrated, you should be fine as long as you get back onto charge SOON, however, if your meter is out of calibration, it can SAY 0%, but be at 2.9V or 2.85V - dangerously low, and might be unresponsive to the charger (White light of death or bootlooping). SOOOOOO.....
Heed thy words, my child, lest you be without the power!!
