White Light of Death?

Discussion in 'Smartphone Battery Discussion' started by Celes, Feb 13, 2012.

  1. Celes
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    Celes New Member

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    My Razr Maxx died. When I plugged it in I didn't get the usual run through of the start up screens or the battery charging indicator showing me it was at 0%. Instead the battery light is now lite up white. Usually I only have to wait about 5 mins or so to turn the phone back on. I have had it on the charger for over an hour and theres is no difference. There is no battery indication of charge and the white light is still on. My phone will not turn on. Anyone know anything about this? Thanks
  2. thaDroidz
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    thaDroidz New Member

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    I have no ideas, but definitely want to watch for an answer...


    Is it possible to do to "power/ volume up" reset to do any good?

    ----posted maxx'ed out----
  3. mikeyk61
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    mikeyk61 New Member

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    Possible Solution

    I had the same issue. White light, tried different outlets, jiggled the cord and nothing for 12 hours. I then tried different plug in my car and almost instantly up to 5% charge. Now fully working on plugs at work,so you can try this. It may work....

  4. BroidDrionic
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    BroidDrionic New Member

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    This happened with my bionic one time. As has been said, I tried popping it in my car dock and it instantly booted. Wall chargers and USB ports just weren't cutting it I guess.

    Sent from my DROID BIONIC using DroidForums
  5. mikeyk61
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    mikeyk61 New Member

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    My wall chargers work great (and the car charger)! They (wall chargers) provide the most current, I believe. The one I had at home, that wont charge and causes white light, will be thrown away. I think it is old and possibly broke inside.
  6. FoxKat
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    FoxKat DF Super Moderator Staff Member Premium Member

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    There are several threads here and many more on other forums about phones that were allowed to "die", or in other words, drained to 0% and shut down on their own. There is considerable risk in doing this. Once the phone's battery reaches 0% (about 3V), it's not very far from being unable to accept a charge at all.

    From Batteryuniversity.com (Battery Fuel Gauge: Factual or Fallacy? - Battery University

    Over-discharging Lithium-ion


    • [*=1] Li-ion should never be discharged too low, and there are several safeguards to prevent this from happening. The equipment cuts off when the battery discharges to about 3.0V/cell, stopping the current flow. << This is what I mean by allowing it to "die"

      If the discharge continues to about 2.70V/cell or lower, the battery’s protection circuit puts the battery into a sleep mode. This renders the pack unserviceable and a recharge with most chargers is not possible. << And THIS is what I mean about risking the battery being unable to accept a charge at all. These batteries CAN in most cases be BOOSTED back into charging mode with a high-voltage charge for up to 1 minute and will continue to function normally from there on, but this is something that normally requires specialized equipment and must be done carefully since the risk of failure is great.

      To prevent a battery from falling asleep, apply a partial charge before a long storage period.[*=1]Do not recharge lithium-ion if a cell has stayed at or below 1.5V for more than a week. Copper shunts may have formed inside the cells that can lead to a partial or total electrical short. If recharged, the cells might become unstable, causing excessive heat or showing other anomalies. Li-ion packs that have been under stress are more sensitive to mechanical abuse, such as vibration, dropping and exposure to heat.

    There have been many examples of people who couldn't get their phones to either begin charging or even boot up once they've shut themselves down at 0%. In some cases it took overnight before the phone became responsive, others like those mentioned here in this thread were able to jump-start them with the car adapters (which put out higher current). This ISN'T the "protection mode" described above, but instead a voltage level that is just too low and current requirement too high to support the phone's display and charging circuit while also providing the battery enough charging to allow it to rise above the rate of consumption by the phone's start-up draw. This is why in those cases, a higher current charger was able to get it back out of its stalled state.

    In the diagram below you'll notice in the "stage 1" charging (far left), the battery is able to accept and will pull 1 Amp of current (dotted line) when the voltage is very low - under 3V (solid line), and yet the phone requires a minimum of just over 3V to wake up (whether into Charge only mode or full booting). If the current is insufficient to allow the voltage to rise to 3V or better, and in the mean time the phone's motherboard is trying to get 3V+ and pulling current in the process, the battery can't catch up and so the voltage remains below the 3V+ threshold, the phone doesn't wake, and the battery stalls in the charging state at under 3V.

    Also the stock charger only supplies 750mAh, or 7/10 of an Amp at 5.1V, then the charging circuitry on the phone takes the 5.1V at 750mA and down-converts it to 4.2V at is able to supply about 800mAh or so. This means it's even more difficult for a deeply discharged battery to compete with the motherboard for power.

    View attachment 48196


    Conclusion...DON'T allow the phone to "die" at 0% on its own, charge as soon as possible after the phone indicates "Low battery", which is at 15%. If the battery does discharge fully by accident, charge as soon as possible so that the voltage doesn't continue to drop due to normal discharging and potentially put you into one of the undesirable situations mentioned above.

    Charge often, don't worry about charging fully, the battery actually prefers shorter partial charges and it will last longer over time for it.
    Last edited: Mar 9, 2012
  7. Dianaa
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    Dianaa New Member

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    I have the same problem with the white light and am clueless also
  8. altjx
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    altjx New Member

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    FoxKat, thank you very much for this information. I've always heard that it should be "drained" at least once a month to maintain maximum battery life, but I've always assumed this meant let the phone cut off itself. Thankfully, last night I put it on the charger with it was a little less than 15%.
  9. FoxKat
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    FoxKat DF Super Moderator Staff Member Premium Member

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    The method of draining the battery on an infrequent basis was a spill-over from the Nickel Cadmium battery days (more than a decade ago), and to a lesser-extent Nickel Metal Hydride. Those batteries had a characteristic whereby if you used it for only a portion of its full charge on a regular basis, eventually the battery would "assume" that amount of charge consumed as its full capacity.

    For instance, let's say you used an average of 60% of the battery's capacity, so you charge to 100% overnight, then use to 40%, then repeat, and you do that for several months. What would happen is the battery's internal chemistry would essentially build up crystals (Dendrites) that occupied the space originally occupied by the Cadmium paste which allowed charge to happen, essentially blocking that portion of the battery's physical space from being active and able to maintain a charge. So eventually even if it was fully charged, it would start dying at 40%, rather than continuing to provide power to 0% as expected. By repeated deep-discharges followed by repeated full charges, the battery would reclaim some of that space by breaking down the Dendrites. This worked - somewhat.

    Eventually, there was a system developed by Cadex (the parent of BatteryUniversity.com), which would "zap" the batteries with a series of quick high voltage jolts that helped to break up those dendrites and reclaim more of the battery's charge capacity (see Battery charger and battery analyzer experts - Cadex Electronics Inc.). I still have the one I purchased back in the 90s, and used to keep my Motorola Flip Phone batteries going strong. By using this technique, they could reclaim upwards of 90% or more of the original capacity and revive batteries that would have otherwise been thrown away and replaced. The savings for fleet management (such as Police, Fire, Ambulance, Security, etc.) was tremendous. The term coined by Cadex was "Battery Conditioning". This has led to the same terms and deep discharging techniques being incorrectly applied to "other" battery chemistry. This is totally effective ONLY with Nickel Cadmium batteries and should NOT be applied to ANY other battery chemistry.

    Today there are "Universal Battery Conditioners and Chargers" which are intelligent and can detect the type of battery being tested and charged, and will change the charging algorithm to fit the particular battery chemistry. Since some batteries (namely Lithium based batteries) can't be continually charged or they will rupture violently, these universal chargers are equipped to shut off charging when the battery has reached its optimum charge, then monitor it to assure full charge and "top off" as necessary while on stand-by. For us, our phones have a similar version of the same smart battery charging technology built it, so as long as you use the phone and the original charger supplied by Motorola, you'll never have to fear a problem.
  10. altjx
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    altjx New Member

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    Does this mean that there's no harm in charging and unplugging throughout the day that can/will potentially negatively affect the battery life?
  11. Trash Can
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    Trash Can New Member

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    Small charges of short duration throughout the day are good. There's evidence that this practice will prolong battery life.
  12. FoxKat
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    FoxKat DF Super Moderator Staff Member Premium Member

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    Trash Can is 100% correct. For example, it is better to charge from 20% to 60% and then again from 20% to 60%, rather than from 20% to 100%. Shorter charges, on average from 25% to 75% of capacity will extend the battery's total life from 500 100% charges to as much as either 1,000 75% charges or 1,500 50% charges (each yielding 750 100% charges) or to 2,500 25% charges (yielding 625 100% charges).

    Based on those numbers, it looks like the "sweet spot" is somewhere near or between 50% and 75% per charge. This falls right in line with the manufacturer's recommendation that you place the phone on charge as soon as the "Low battery" warning signals at 15%, and that the phone will maintain a full charge at somewhere between 90% and 100% of rated capacity (15% reserve plus 10% cushion = 25% variance against capacity, leaving 75% charge in the cycle).
  13. altjx
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    altjx New Member

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    Wow, 20% to 90%? I would have never guessed that range, haha.

    I was curious because I have a habit of keeping my phone on the charger when I'm not talking on the phone or when I'm docked in a location (i.e. work, home) but I wasn't sure if there was such thing as "overcharging"
  14. Skull One
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    Skull One New Member

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    That information is 100% incorrect and will SHORTEN your batteries life. No if, ands or buts to that. Stage 1 charging is usually from 0 to 85% of a consumer grade Lithium-Ion battery. Stage 1 charging is the MAXIMUM AMPERAGE allowed during the charging cycle and this puts the MOST strain on the chemical reaction that is occurring. This is also the LEADING CAUSE of anode plating which is what leads to premature death of a Lithium-Ion Battery.

    Anyone following this advice is simply killing their battery early for NO REASON.

    You want to charge from 60% to 100% so you spend LESS TIME in Stage 1 charging and do less damage to the battery. The sweet spot is actually 85% to 100%. Because that is when the lowest amperage is used to charge the battery. Which puts less stress on the chemical reaction that is occurring.
  15. FoxKat
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    FoxKat DF Super Moderator Staff Member Premium Member

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    First off Skull One, let's turn the volume down a bit. Nobody enjoys reading a post that is entirely in BOLD and contains LOTS OF CAPITAL LETTERS!

    Now, let's go back over this again. I never said that it was better to charge from 20% to 60% rather than from 60% to 100% (note, the same 40% of charge in each example). What I said was charging from 20% to 60% over several cycles was better than charging from 20% to 100% over the same collective percentage of charge (i.e. two charges of 40% + 40% is better than one charge 80%). It has been proven that shorter charge cycles prolong the battery's useful life. The chart in the image below and the explanation included therein prove what I've said. You are taking my words and comments out of context and making them appear to justify your view as an opposing one. See below;

    View attachment 50319

    Next, to say that Stage 1 charging for these phones is 0% to 85% is a misleading confusion of specifications (capacity versus useable rated current capacity). If you wish to use the percentages of useable rated current capacity as a measure, you need to be clear, since 0% of the entire battery's capacity would be a completely dead battery and it would have been in "protection mode" long before it ever reached 0%.

    More correctly said, Stage 1 charging for these phones IS from about 3V (
    what the manufacturer has set as the minimum voltage and calibrates the meter to identify as 0% of useable current capacity,) to about 4V (which the manufacturer identifies as 90% of the difference between the 0% threshold and the maximum safe charge capacity). Stage 2 charging is from 90% of usable rated current to 100% of usable rated current at maximum safe charge level, or better said, from about 4V to about 4.2V (see chart below):

    View attachment 50323

    It is true that charging at "maximum amperage" (the maximum current the battery will pull if given an unlimited amount of current from which to draw) as you state "can be" detrimental to a Lithium based battery, but due to the heat which creates the stress. Anode plating occurs during periods of elevated temperature during charging, and when charging beyond the recommended maximum voltage which also increases heat. In fact, heat IS the number one cause of premature death of a Lithium based battery.

    However again, taking things out of context and also applying scenarios from one world to another totally unrelated world will result in misinformation and resulting incorrect conclusion. See quote from BatteryUniversity.com;


    "Prolonged charging above 4.30V forms plating of metallic lithium on the anode, while the cathode material becomes an oxidizing agent, loses stability and produces carbon dioxide (CO[SUB]2[/SUB])...

    Charge currents with Li-ion are less critical and can vary widely. Any charge will do, including energy from a renewable resource such as a solar panel or wind turbine. Charge absorption is very high and with a low and intermittent charge, charging simply takes a little longer without negatively affecting the battery."


    Yes, in the RC world, where the charge rate of these batteries is often controlled not by the charger, but by the operator, these batteries are often overcharged in hopes of getting more out of the battery and also in hopes of getting "back into the race quickly", and can result in early failure and also in catastrophic self-destruction. Overcharging is the "LEADING CAUSE of anode plating". This is NOT the RC world. Quote from BatteryUniversity.com;


    "Increasing the charge current does not hasten the full-charge state by much. Although the battery reaches the voltage peak quicker with a fast charge, the saturation charge will take longer accordingly. The amount of charge current applied simply alters the time required for each stage; Stage 1 will be shorter but the saturation Stage 2 will take longer. A high current charge will, however, quickly fill the battery to about 70 percent."


    So what have we learned here? It is that charging rapidly will give you a rapidly replenished battery, but not to 100%, instead to about 70% of usable capacity, and in fact rapid charging of these batteries only shortens the entire charge cycle to 100% of usable capacity by a small amount of time.

    Now, let's talk about charge rate. The rate at which these phones are allowed to charge (or better said, the current level supplied by the charger) is set by the charging circuitry. These phones are very tightly controlled in their charge rate by the charging circuitry and it is set to limits for current, voltages, time, and temperature that can not be easily circumvented by the operator - mainly to prevent the issues related to Lithium based batteries commonly suffered in the RC world.

    What IS detrimental to these batteries when charging at a high current is heat. Heat in our phones' cases, is the battery's worst enemy. The battery for the RAZR is 1,750 mAh (1.75A), so to charge at even 1C (which is considered the upper limit of safe charging rate by the RC world), would require a charger that could produce 1.75 Amps. The stock Motorola charger only puts out 750mAh maximum (which is less than half that amount), so for our phones, the charger is charging at a rate of 0.43C, and extremely low rate and virtually impossible to cause stress of the battery.

    Not to mention the phone has a current limiter circuit built in to prevent charging at elevated current levels, so even if you DO charge with a 2 Amp charger, such as a Apple iPad charger which puts out 2.1 Amps, the phone will only allow the safe current levels set by the manufacturer. That's not to say that the current limiter couldn't fail and allow the battery to pull up to the full 2.1 Amps, which is why the stock Motorola Charger only supplies 750mAh. See quote below from BatteryUniveristy.com:


    "The charge rate of a typical consumer Li-ion battery is between 0.5 and 1C in Stage 1, and the charge time is about three hours."


    Here's a copy of page 3 of the RAZR/MAXX Owner's Manual, and you'll notice on the left in cell 3, the little clock with the 3H on it, to signify 3 hours!!

    View attachment 50322


    To coin your own signature phrase...

    "
    Facts are a wonderful thing. They can be proven true or false. Opinions on the other-hand aren't facts and generally get argued to death. I wonder which one is more helpful normally?"

    Last edited: May 23, 2012
  16. Skull One
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    Skull One New Member

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    Would you be so kind and please explain the discrepancy between the two following post.

    On May 22nd 2012 (yesterday) you posted the following information to prove your point.


    On March 25th 2012 you PASTED the following information from Battery University to prove your point. (source http://www.droidforums.net/forum/dr...ery-dead-all-you-naysayers-3.html#post2062430)

    Do you see the contradiction? If not let me explain what I see in regards to your posts.

    Depth of Discharge is the depletion of the electrons or "stored energy" in a Lithium-Ion battery. Using that chart, that you posted no less, if you take the battery from a 100% charge to 0% charge, you will be able to "on average" do 500 full charges. And at the end of that time frame, you will have a battery that will be able to maintain 80% of the original potential storage capacity of the battery when it was original constructed. Per the current specification of consumer grade Lithium-Ion batteries.

    The next line shows that if you go from 100% charge and then DISCHARGE the battery to ONLY 50% and then recharge it back to 100% you will be able to on average perform 1500 of those recharges. And again at the end of that time frame you will have a battery that is capable of maintaining 80% of the original potential storage.

    The next line shows that if you go from 100% charge and then only discharge to 75% charge that you will, again on average, be able to charge the battery 2500 times.

    100% down to 90% execrate execrate...

    That Depth of Discharge chart specifically show that by only going from 100% down to 50% and NOT BELOW that point of discharge that you have the potential to maximize the performance of the battery. The reason for that is very CLEAR based on the chart you having been pasting.

    [​IMG]

    That chart shows as you approach 100% charge the amount of amperage (the dashed line) used to charge the battery is reduced. It is done that way to help prolong the life of the battery by placing LESS STRESS on the chemical compound in the battery and to also help avoid any potential plating of the Anode. Lets leave RC cars out of the discussion, it only clouds the issue and isn't relative to my points.

    So by using your own posts and then PROPERLY interpreting the data it shows you don't ever want to get below the 50% charge level to get maximum usage from the battery. So your suggestion that you want to charge from 20% up to only 60% and repeating that habit flies directly against the VERY DATA you posted as FACT. Because from 20% to 60% you will be in the FULL 100% amperage charging rate the entire time vs the 50% to 100% in which you will only be in the full 100% amperage range for 70% of the charge. And hence why I suggested they should only discharge to 60% because then you are only in the full 100% amperage charging rate for 62.5% of the time.

    These are your posts and your reference material. Why have you posted conflicting information?
  17. cereal killer
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    cereal killer DF Administrator Staff Member

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    Hello gentlemen! Great topic and info!! Just a friendly reminder to keep the debate civil and definitely keep the info flowing. Thanks guys!!
  18. thaDroidz
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    thaDroidz New Member

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    Battle of the really long replying battery gods!
    :)

    I have great respect for both of these "dudes" just poking fun

    ----posted MAXXED OUT WITH dessert----
  19. cereal killer
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    cereal killer DF Administrator Staff Member

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    Moved to new forum!!!
  20. FoxKat
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    FoxKat DF Super Moderator Staff Member Premium Member

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    Sure Skull One, I'd be happy to clarify. I believe you and I are not far apart in our beliefs but perhaps there is a major and distinctive divergence in interpretation of the data and that is the root of our differences. It's easy to clean this up from my point of view. I'll address them now.
    [​IMG] Originally Posted by FoxKat [​IMG]
    Trash Can is 100% correct. For example, it is better to charge from 20% to 60% and then again from 20% to 60%, rather than from 20% to 100%. Shorter charges, on average from 25% to 75% of capacity will extend the battery's total life from 500 100% charges to as much as either 1,000 75% charges or 1,500 50% charges (each yielding 750 100% charges) or to 2,500 25% charges (yielding 625 100% charges).

    Based on those numbers, it looks like the "sweet spot" is somewhere near or between 50% and 75% per charge. This falls right in line with the manufacturer's recommendation that you place the phone on charge as soon as the "Low battery" warning signals at 15%, and that the phone will maintain a full charge at somewhere between 90% and 100% of rated capacity (15% reserve plus 10% cushion = 25% variance against capacity, leaving 75% charge in the cycle).​


    First, I don't see the "conflicting information" you indicate and question. In both posts, I maintain the same position which is that it is better to operate the battery in the middle of the charging range rather than either in the top or bottom ranges. The ONLY difference I see is the mention of the sweet spot being between 50% and 75% of charge in one and between 25% and 75% in the other. The difference is only because in the 50% to 75% range post I was using the actual posted data on the chart, and the other post I was iteratively extrapolating a wider hypothetical range based on the factors at the lower end of charge depletion.

    The above information is based on the chart as you mentioned, and also on additional information provided in the plethora of data on the BatteryUniversity.com website (as well as a myriad of other sites I visit, books I've read, magazines I subscribe to, etc., but I kept it to BatteryUniversity.com for simplicity). The key issues are as follows:

    Charging in the low range of the charge capacity, or in other words in the range not near 100% of usable capacity, but perhaps staying in the lower 80% comes from the results of the chart first, but also other text I will follow with. The chart must be understood completely to extract the accurate conclusion. The Depth of Discharge (DoD) is as you say a reference to how much you come off of the 100% of usable capacity mark - let's call it a full charge to 100%. So a DoD to 50% would be using 50% of the 100% full charge, the same as 50% remaining. This seems quite obvious and it is. So therefore, a DoD of 25% would indicate a remaining charge of 75%, right? Right.

    Now, what we also have to understand is the number of cycles in that chart is NOT the number of 100% charge cycles on every line, but ONLY works out to be so on the 100% DoD line. It is actually referencing the number of charge cycles at the percentage required to replenish the DoD referenced on that line, so for example, in the case of a 50% DoD, it says you will get 1500 cycles, however that's 1500 50% cycles, which if you do the math is equivalent to 750 100% cycles. So it's fairly safe to say that if you maintain a DoD cycle pattern of 50%, you will gain about 50% of expected battery life (500 100% cycles versus 750 100% cycles, or 250 more 100% cycles against the original 500, or 50% more life).

    So it seems that the chart indicates that with less and less DoD cycles (10% versus 25%, 50% or 100%), that you will get "more and more" life out of the battery. Unfortunately it will lead you to that belief if you don't do the math. As it is clear now, 500 cycles in the case of the 100% DoD (500 100% cycles) is actually a LONGER battery life than 4700 cycles in the case of the 10% DoD (470 100% cycles). That single piece of evidence is perhaps the most overwhelming evidence that proves my claim from the beginning and proves I have been 100% correct all along.

    Also, expected battery life (or end of usable life) is different depending on which manufacturer you talk to. You mentioned 80% as the expected "end of life" (*and that may be what Motorola chose - though I don't know*), but for this chart, it isn't 80% of original rated capacity (capacity when it left the factory), but is 70% of original rated capacity as written in the text accompanying the chart "We assume end of life when the battery capacity drops to 70 percent. This is an arbitrary threshold that is application based.". So with 50% DoD cycles, you're getting 750 100% charges that start out with the battery being able to hold a charge which is 100% of original rated capacity, and decrease gradually as the capacity of the battery diminishes, and ends in the 750th cycle with the battery being able to hold only 70% of the original rated capacity, so in that example in that last 100% cycle you're getting a 100% charge cycle of the now reduced 70% of original rated capacity.

    Now let's look at why it's better to remain in the lower charging range rather than the upper. In the chart, it says that a 100% capacity DoD cycle will yield 500 cycles. It also says that a 25% DoD cycle will yield 2,500 cycles. What we have to first do is convert the number of cycles at that percentage of DoD to a common percentage, so using 100%, we can compare against 100% DoD cycles. To do that, a DoD of 25% means that it takes 4 25% DoD to equal 1 100% DoD. So dividing 2,500 by 4 gives you a result of 625, meaning 2,500 25% DoD cycles will yield the effective capacity of usable charge as would 625 100% DoD cycles. So yes, only discharging to 25% DOES yield a longer battery life than discharging to 100%, in fact a 25% longer life. So this seems to prove what you said earlier - that maintaining the charging in the top of the charge cycles (and with the top 10% being at the lower "saturation current" or "Stage 2") is better for the battery.

    But what you're missing here is that if that were an accurate indication of the beginning point of a trend at the top end, and using the known 100% DoD number of 500 cycles as the truly accurate indicator of the end point, then going to a 50% DoD would yield somewhere in between, and LESS net 100% charge cycles than 25% DoD, and in fact it's not so. The 50% DoD cycle actually yields 1,500 50% cycles, and since it takes 2 50% cycles to equal 1 100% cycle, you divide 1,500 by 2 and you get 750...750 100% cycles.

    But wait...let's try to disprove what I've just said by looking at 10% DoD cycles...surely 4,700 10% cycles should prove me wrong, especially if your claim of Stage 2 charging being LESS stressful on the battery than Stage 1 charging is accurate, right? Well, if it takes 10 10% cycles to equal 1 100% cycle, then dividing 4,700 by 10 results in 470 100% cycles - which is LESS than the 500 100% cycles at a 100% DoD. This means your battery will last LONGER if charged to 100%, discharged to 0% and then charged to 100% again every time, than it will if charged to 100% and discharged to 90%, and then charged to 100% again...the top 10% of the charge cycle...the Stage 2 that you were saying is the LEAST detrimental to the battery. It is also LESS than the 750 100% cycles at 50% DoD, and even LESS than the 625 100% cycles at 25% DoD.

    100% DoD = 500 100% cycles, which = 500 100% cycles

    50% DoD = 1,500 50% cycles, which = 750 100% cycles (the sweet spot begins somewhere between 100% DoD and 50% DoD, so I used 75% DoD as a crude interative guess - see below)
    25% DoD = 2,500 25% cycles, which = 625 100% cycles (and continues here)
    10% Dod = 4,700 10% cycles, which = 470 100% cycles (and drops off to below 100% cycles here)

    75% DOD = a hypothetical 1,000 75% cycles, which = about 750 100% cycles

    So, to reiterate, your battery will last longer if you do NOT charge to 100% with each charge, and instead remain in the range of between a 25% charge and a 75% charge (as a hypothetical upper limit). In other words, it's not whether you are charging in Stage 1 or Stage 2, but whether you are keeping the battery at or close to its maximum charge capacity over either longer or shorter segments of time for each charge cycle.

    The real upper limit which might get us to lets say 625 100% cycles (giving us a range from 625 to 750 100% cycles across the major middle of the charge cycle) may actually be 80%, or it might be 85%, but it is definitely going to be a lower number of cycles as you approach the top 100% of the charging cycle range as these numbers clearly indicate (470 100% cycles at 10% DoD). This is why I indicated it would have been helpful to see 10% increments across the entire range. 5% increments would have been even more revealing but perhaps overkill.

    By the way, the example above is what is known typically as a "Bell Curve" where the worst performance is at the tops and bottoms of the ranges, or at the leading and following edges of the bell, and the best will be somewhere in the middle of the range as identified by the top of the bell. When they engineer batteries, they do so with a "range" of "typical" use and that range is where they target the best performance. In the case of batteries in cell phones, on average, the greatest percentage of batteries spend the greatest percentage of their charge range in the MIDDLE of the range, not at either the top or the bottom, so it only makes sense that if you want the best performing battery for those ranges, you would want a battery that lasts longest if charged between 25% and 75% of the entire range most of the time (the major portion of the bell curve - the middle)

    Now to further bolster my claims (not that the data doesn't already irrefutably prove them), here's a couple more quotes from BatteryUniversity.com;

    "Lithium-ion does not need to be fully charged; a partial charge is better."
    Interpretation...a partial charge is better than a full charge (not that a partial discharge is better than a full discharge), or in other words, its better to NOT charge to 100%, no matter whether you are using 10% in each DOD cycle or 75%. So doing 25% cycles, if starting at 75% charge level, decreasing to 50%, and then charging back to 75% WOULD yield better results than 25% cycles starting at 100%, decreasing to 75% and charging back to 100% and the chart proves it. Furthermore, doing 25% cycles starting at 60% and decreasing to 35% is also likely going to yield better results than 100% to 75% and back, since even 100% cycles outperforms 10% cycles, which also disproves the Stage 1 versus Stage 2 theory that Stage 2 charging is less stressful than Stage 1 charging when all other factors are considered.

    Another quote to prove the above paragraph;

    "Li-ion does not need to be fully charged, as is the case with lead acid, nor is it desirable to do so. In fact, it is better not to fully charge, because high voltages stresses the battery. Choosing a lower voltage threshold, or eliminating the saturation charge altogether, prolongs battery life but this reduces the runtime."

    Eliminating the saturation charge altogether, prolongs battery life...that means if I ONLY charge in Stage 1 to 90% of usable current capacity and never actually go to a Stage 2 charge for the last 10%, I will extend the life of my battery! So again, completely proves my point and completely disproves yours.

    And yet another quote;

    "Avoiding full charge has benefits, and some manufacturers set the charge threshold lower on purpose to prolong battery life."

    So what they're doing here is essentially "Eliminating the saturation charge altogether", or eliminating Stage 2 of the charging cycle.

    Now, another comment you made which had me a little baffled is "depletion of the electrons or 'stored energy'". In a battery the electrons are neither depleted during discharge, nor are they replenished during recharge. The law of conservation of energy is a law of physics. It states that the total amount of energy in an isolated system (read sealed Lithium battery) remains constant over time. The total energy is said to be conserved over time. For an isolated system, this law means that energy can change its location within the system (move between Anode and Cathode, and that it can change form within the system, for instance chemical energy can become kinetic energy, but that energy can be neither created nor destroyed.

    In the case of a Lithium battery, during charge and discharge, ions move between the cathode (positive electrode) and the anode (negative electrode). During discharge, the anode undergoes oxidation, or loss of electrons, and the cathode sees a reduction, or a gain of electrons. Charge reverses the movement. In other words, the net effect is the electrons are simply shifted from the cathode to anode and back again (through the charging or discharging circuit).

    The number of "free electrons" in a battery is determined NOT by how much it's charged, but by the chemistry of the battery internally. All charging does is cause an electrochemical reaction (or in the case of Lithium Ion batteries, an Ionization reaction), which releases electrons from their bond with or near either the anode or cathode and causes them to move freely to the opposite pole through the "closed circuit" outside the battery. The only time electrons actually leave the battery is during charge or discharge, and they are never "depleted". Every electron that leaves the negative terminal of a battery is replaced by an electron at the positive terminal, so it's not a depletion of electrons, but an exchange of electrons that creates the flow.

    The reason a battery will eventually take less of a charge is NOT due to electron depletion but due to electrons becoming trapped at either the Anode or Cathode due to the breaking down of the internal battery chemistry, the loss of electrolyte (Lead Acid), increasing of internal resistance, the buildup of crystals in the electrolyte (Nickel Cadmium), plating if the anode with metal (Lithium) or any other number of internal electrochemical causes, but NOT due to "depletion of electrons".

    To summarize...

    The overriding debate here was whether using the top of the charge cycle as the basis for power (90% to 100% of usable capacity), or anything under that (the 0% to 90% portion of the usable capacity) would either extend or shorten the battery's life. It has been proven here beyond a shadow of a doubt that operating a battery in the top range of charge is detrimental to the lifespan of the battery and that by operating in a range between perhaps 25% and 85% of the total usable capacity of the battery will in fact extend its lifespan. There is plenty of third party evidence to corroborate that claim:


    "Avoid charging to 100% capacity. Selecting a lower float voltage can do this. Reducing the float voltage will increase cycle life and service life at the expense of reduced battery capacity. A 100-mV to 300-mV drop in float voltage can increase cycle life from two to five times or more."

    "Use partial-discharge cycles. Using only 20% or 30% of the battery capacity before recharging will extend cycle life considerably. As a general rule, 5 to 10 shallow discharge cycles are equal to one full discharge cycle. Although partial-discharge cycles can number in the thousands, keeping the battery in a fully charged state also shortens battery life."

    "With present battery technology and without increasing battery size, you can’t get both longer run-time and longer battery life. For maximum run-time, the charger must charge the battery to 100% capacity. This places the battery voltage near the manufacturer’s recommended float voltage, which is typically 4.2 V ±1%. Unfortunately, charging and maintaining the battery near these levels shortens battery life."

    (ref: http://lancair.net/lists/lml/Message/56976-02-B/Li-Ion Battery Life.pdf)

    "* partial-discharge cycles can greatly increase cycle life, and charging to less than 100% capacity can increase battery life even further."

    (ref: Increase Your Battery Life / Save Your Time)

    "Avoid full charging when you can.
    "

    "For pure electric vehicles, avoid deep discharging your battery pack.
    "

    (ref: Eight tips to extend electric vehicle battery life)

    "Avoid full charging when you can.
    One reason that batteries in mobile devices only last a couple years is that they are being pushed to their maximum capacity—frequently getting fully charged and fully drained. Consumer products are advertised by their battery operation time, not their battery lifespan. This means that every possible electron will be shoved in there. Charging to maximum capacity might give you the most possible use for that one charge, but it is one of the worst things that you can do to lithium batteries.

    In the 2011 Nissan LEAF, there is a Long Battery Life setting that tells the car to stop charging at 80 percent. This reduces the available range, but could greatly increase the lifespan of your battery pack. If your normal daily driving can be done with less than an 80 percent charge or you can charge mid-day, this simple setting is one of the easiest things that you can do to increase the battery’s lifespan.

    One additional advantage of not charging up all the way is that it leaves room to store energy from regenerative braking. Often when the batteries are full or near full, regen will be disabled to avoid overcharging the batteries.

    Avoid deep discharging your battery pack.
    Lithium-ion packs prefer a partial cycle rather than a deep discharge. Since lithium-ion chemistries do not have a memory effect, there is no harm using a partial discharge. Not only will this avoid excessive wear, it will also mean that—with a little planning—you will arrive at your destination with range to spare."

    (ref: Eight Tips to Extend Battery Life of Your Electric Car | PluginCars.com)

    "Standard mode charges bring the battery up to 80-86% and only allows it to discharge down to 20%. So that's closer to the 50% sweet spot the battery cells like."

    (ref: Charge in Standard, Drive in Range)

    If you need additional references to further bolster my claims please PM me out of respect for the rest of the forum members. And as a side note, lets try to focus the balance of our future combined knowledge and energies on helping others and not on trying to prove each other wrong.
    Last edited: May 24, 2012
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