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  1. flyingkytez's Avatar
    Is the external battery charger using slow charging 1.0? It seems as so. Also, does fast charging reduce the lifespan of the battery? I've been using a laptop fan to blow at the external battery charging cradle to keep the battery cool when charging. Will this help make the battery last longer?
    04-16-2018 12:40 AM
  2. Laura Knotek's Avatar
    Are you using the LG battery charging kit? I have one, and I use it to charge an extra battery for my V20. Yes, it is slower, but I don't think it hurts the battery life.
    04-16-2018 01:35 AM
  3. tickerguy's Avatar
    The external cradle actually follows the proper protocol for lithium battery chemistry.
    huntnyc likes this.
    04-16-2018 10:23 AM
  4. flyingkytez's Avatar
    Are you using the LG battery charging kit? I have one, and I use it to charge an extra battery for my V20. Yes, it is slower, but I don't think it hurts the battery life.
    Yeah I am using the official LG battery cradle. It does seem like 1.0 charging. People are using fast charge 3.0 and I wonder if it lowers battery life.
    Laura Knotek likes this.
    04-16-2018 10:39 AM
  5. Rukbat's Avatar
    As long as the charge doesn't exceed the capacity (in other words for a 3000mAh battery, doesn't exceed 3 Amps charging), and the battery isn't overheated, there's no problem. A lithium battery can be charged up to 1C - 1 times the capacity. A regular 100% charge at 25°C will degrade the battery to 80% capacity, regardless of the charge rate.

    The real problem is the amount that the battery is charged to. A 75%-to-30% cycle seems to give about the longest life.
    Mooncatt likes this.
    04-16-2018 01:05 PM
  6. tickerguy's Avatar
    As long as the charge doesn't exceed the capacity (in other words for a 3000mAh battery, doesn't exceed 3 Amps charging), and the battery isn't overheated, there's no problem. A lithium battery can be charged up to 1C - 1 times the capacity. A regular 100% charge at 25°C will degrade the battery to 80% capacity, regardless of the charge rate.

    The real problem is the amount that the battery is charged to. A 75%-to-30% cycle seems to give about the longest life.
    Well that's just not true, but go ahead and believe it. While there is some stress (and shorter service life) that occurs from running the charge all the way to 100% the bigger issue -- and what costs you roughly half the design cycle life of the battery -- is *how* cell phones get to 100%.

    Yes, it's true that you can charge a Li chemistry battery at 1C without damage -- provided you switch to constant voltage charging at 4.2V.

    The problem with running the charge at 1C is that when you reach 4.2V the battery will only be about 65% charged. You then have to hold the voltage at 4.2V and let the current taper. If you charge at ~0.6-0.7C instead of 1C it'll reach that point at about 75-80% charge.

    Either way the bulk + saturation phase takes about 3.5-4 hours from empty to full. The difference is that you can run the 1C charge to ~65% in about 40 minutes and then go ahead and use it, which is nice and fast.
    At 0.6C to get to 75-80% or so it's about an hour and a half or a bit more.

    But what all the phone charger circuits do is run the bulk phase materially above the proper voltage before they transition to saturation, which does charge faster to "full" (by about half the time!) but it also damages the battery as the so-called "saturation" charge current never really tapers off properly since the voltage is too high. The reason they do it is that nobody likes waiting 3-4 hours for a full charge as that last 10-15% takes a long time to do correctly without material amounts of damage; everyone wants their battery full in less than 2 hours, and you can't get that with a proper charge profile. This is also why you get plenty of heating; they're basically force-charging the cell beyond the rate it can cleanly accept the energy which "works" -- but damages it at the same time.

    A decent compromise is to use something like Accubattery and set it to 80% to alert, then disconnect it when you get there. This will not run the bulk phase too far over the proper cut-off and as a result you'll roughly double the time (in calendar time) before you have to replace it.
    04-16-2018 07:56 PM
  7. Mooncatt's Avatar
    But what all the phone charger circuits do is run the bulk phase materially above the proper voltage before they transition to saturation, which does charge faster to "full" (by about half the time!) but it also damages the battery as the so-called "saturation" charge current never really tapers off properly since the voltage is too high.
    I've seen you make this claim numerous times. Do you have any evidence to back it up, because my own monitoring shows proper charge patterns are used. Running above the voltage the battery is designed for can also cause an explosion risk.

    I will add a couple qualifiers to my opinion, though. Current Li-ion technologies have resulted in "high voltage" batteries capable of 3.85V nominal (4.4V peak). Phones with these batteries, like the V20, can and do run up to 4.4V during charging. Also, 100% on the meter doesn't always equate to a fully charged battery. I've noticed the charge current lasting quite a while after the meter shows 100% before fully tapering off. One could speculate this is to get people to unplug before putting too much stress on the battery.
    04-16-2018 08:22 PM
  8. tickerguy's Avatar
    I've seen you make this claim numerous times. Do you have any evidence to back it up, because my own monitoring shows proper charge patterns are used. Running above the voltage the battery is designed for can also cause an explosion risk.
    Well you're happy to believe whatever you want. I have external "smart" chargers that interface to my PC over USB for logging, along with a recording analyzer (that does likewise) and a couple of probe wires into the battery pocket with the back off make it pretty easy to monitor on a removable battery device.

    Second, since I also have said properly-programmed smart charger, I know how long it takes to run a charge using a charger that properly switches to saturation and runs the correct profile. Simply put you can't run a proper charge on a Li chemistry battery from ~10% to 100% in less than about 3 hours without cheating. Proof that these batteries do NOT require a higher charge voltage comes in the form of them reading 100% when charged outboard on a proper Li chemistry charger and then inserting them into the phone and they do indeed read 100%. In addition my recording charger knows how many maH went in as it integrates and reports that over time; combined with my analyzer which can run a controlled discharge test (that I've also done) I've verified that indeed a 3200mah "labeled" battery that Accubattery says has a 3200mah estimated capacity, when discharged at 0.2C, indeed really does deliver 3200mah within a few percent. Thus I know that when charged properly by said external charger I really do store the full capacity of cell into it.
    I will add a couple qualifiers to my opinion, though. Current Li-ion technologies have resulted in "high voltage" batteries capable of 3.85V nominal (4.4V peak). Phones with these batteries, like the V20, can and do run up to 4.4V during charging. Also, 100% on the meter doesn't always equate to a fully charged battery. I've noticed the charge current lasting quite a while after the meter shows 100% before fully tapering off. One could speculate this is to get people to unplug before putting too much stress on the battery.
    CAPABLE of accepting that voltage without metal-plating and catching on fire is not the same thing as treating the cell properly, and getting the designed cycle life out of it. The "newer chemistry" cells can indeed accept charge without turning into torches at a tenth of a volt or so higher charge voltages BUT they still take damage when you run them at said voltage.

    Here's a snapshot of "Accubattery" on my V20 with it at 80%. There is no way that cell is being charged "constant voltage" at 4.386V and ~1,400 ma. Further, there is no way that a proper saturation charge profile from 80-100% would require only 18 minutes to complete. Note that this is a QC3.0 charger and its "average" charge rate during that cycle was just over 2,000mah or just over 63%/hour. It is not possible to run a proper charge profile on a Li chemistry battery and obtain a sub-2-hour complete charge.

    CONSTANT VOLTAGE MEANS CONSTANT VOLTAGE and yet the charge profile on these cells in EVERY phone I've instrumented, whether by app or physical probes on the battery, over the last five years continues to allow the voltage on the cell to RISE beyond its saturation voltage. I've yet to see ONE phone that performs an actual bulk/saturation charge -- that is, charge at up to 1C (if you have the current available) until the saturation voltage is reached and then hold the output voltage CONSTANT and allow the charge current to taper. Instead every phone I've seen over the last many years never actually performs a saturation charge at all; they intentionally overdrive charging from the saturation point all the way until full. What's even worse is that all these charging circuits will then "float" the battery at an effective 100% charge which materially compounds the damage; if you leave the phone plugged in overnight you're hosing your cycle life twice.

    THAT'S WRONG; what SHOULD be done by the charge controller is that when the saturation change-over voltage is reached the voltage should be held CONSTANT (no rise whatsoever) and the current allowed to taper. The logical reason they don't do it that way is TIME. When the saturation charge completes the battery should also not be held on a float charge at all. The correct solution to this is for the charge controller to be able to run the phone as a power supply and to electrically disconnect the battery when the charge is complete so long as it remains plugged in to a power source that can deliver sufficient current. The reason that isn't done is that modern phones can demand upwards of 2A on a burst basis and yet the standard USB port on a computer can only deliver 500ma and there is no way to *know* what the maximum current delivery capability is even on a QC charger (QC negotiation doesn't tell you that, just voltage), so you'd get unsolicited undervolt resets if that was done.

    The reason I recommend using something like Accubattery and disconnecting at 80% is that while this doesn't eliminate charging overdrive entirely it materially reduces the exposure of the cell to it and, if you additionally don't charge overnight at all you will dramatically improve cycle life. It costs you 20% of your runtime before you need to recharge to do that but until phone manufacturers start allowing customers to choose either their "charge me fast" current setting (at the cost of half or more of the design cycle life of the cells) or a "charge me CORRECTLY" setting it's the only reasonable defensive measure you can take.

    If you're wondering what the results look like I've had my V20 now for a number of months and, with the exception of when I'm on road trips and using it for nav (where the abuse of float charging is less than the abuse of continually cycling it during the day, never mind that when screen-on the V20 will not charge at faster than ~500ma so when the screen is locked on for nav the abuse the cell takes is materially lower) this is how I've charged it. You'll note that Accubattery thinks the cell -- the same one I've had in the phone since I got it -- has 102% of it's OEM rated capacity. You can also note the estimated SOT -- approximately 5-1/2 hours and two full days of standby time.

    You do what you want -- I will do what I know, from instrumenting various phones charging circuits and what I know of Li chemistry batteries, works to materially prolong battery life. With a V20 where you can trivially swap batteries this matters less than on a phone with a sealed in the case battery -- on those devices it becomes even more important not to abuse the cell for obvious reasons.
    Attached Thumbnails External battery cradle charges slower?-2018-04-17-07.14.29.jpg   External battery cradle charges slower?-2018-04-17-07.42.57.jpg  
    04-17-2018 07:50 AM
  9. dlcpa's Avatar
    As a soon to be a new V20 user, is it better to charge your batteries in the phone or in separate chargers. I think the car chargers are the worst My Samsung Note batteries expanded and bellied so much so that the cover wouldn't fit and I think the heat it generated through charging, keeping the screen too bright and location services damaged the motherboard and memory locations. Whenever I charged a battery in a separate charger, the battery was always cool, not so in the phone. When I did a factory reset the battery and phone was as hot as can be. Samsung never handled heat well.
    04-17-2018 09:16 AM
  10. tickerguy's Avatar
    The external chargers (like the LG "box" design) have no incentive to force-charge the battery during the saturation phase since "fast" isn't their primary criteria. They also tend to take ~3 hours to fully charge the cell, which is about how long it should take..... and since they don't have to power anything when the battery is full they also have no need to float-charge either (that is, they can actually *disconnect* the battery from charging current when it's full.)

    I haven't yet instrumented the LG external charger but anecdotally it appears to do things the right way in that the battery remains cool the entire time and it appears to take a reasonably-correct amount of time to complete the charge, even when you use a QC3.0 power source to plug it into. If I get some time I'll set up my gear and profile a charge on it after running the battery in the phone all the way down to see exactly what it does.
    huntnyc likes this.
    04-17-2018 10:12 AM
  11. Mooncatt's Avatar
    I discharged my iPossible 6,700mAh battery to 18% before charging this time. As you can see by these graphs, the V20 is doing a proper staged charging cycle. It ramps up to a constant current until the voltage approaches the upper limit. Then it starts to taper the current as the voltage reaches 4.4V and is held steady for the saturation phase.

    Note that full 4.4V isn't reached until AFTER the meter reaches 100%. Current at 4.4V was down to 895mA. At that point, it still took nearly 2 more hours to finally cut off completely after reaching 100mA. In total, it took about 4 hours to charge with barely using the phone during the bulk charging stage (I did turn it on now and then to clear notifications, then back off, which is why you see the quick dips and spikes). I noted that in the saturation phase with current already tapered, lightly using the phone did not result in a reduction in the charging rate.

    AccuBattery reports an estimated capacity of 5,600 mAh and added 4,600 mAh back into the battery during this session. So it seems reasonable to me that the stock battery would take a full charge in the roughly 3 hours recommended with multi-stage charging in the phone.
    Attached Thumbnails External battery cradle charges slower?-capture-_2018-04-17-15-22-56.jpg   External battery cradle charges slower?-capture-_2018-04-17-15-23-09.jpg  
    04-17-2018 03:44 PM
  12. tickerguy's Avatar
    Again you're missing the point.

    CAN you go to 4.4V with these "modern" cells before you go into "saturation"? Yeah, but you're basically "force-charging" the cell beyond 4.2V. The graphene and other "advancements" prevent electrode plating (which is what shorts them and causes fires) at the higher voltage BUT you're not changing the fact that the cell IS being force-charged beyond the point that it can cleanly accept the energy provided which has a material impact on its service life (and, incidentally, a lot of the energy put in at that voltage gets rejected as heat instead of being stored too.)

    Charge time is materially decreased by doing this, which is why the manufacturers do it. However, service life (specifically, cycles before unacceptable degradation occurs) suffers.

    Your high capacity battery was only taking current at ~0.4C during bulk; the phone's charge controller simply can't deliver any more current. That's not a shock given that the phone and its charging circuit was designed for a battery with a 3,200mah capacity and there's no reason for LG to build a charging circuit that can deliver over 1C of current into the stock cell since it cannot effectively absorb energy at a faster rate than that (most of the additional, if you try, will get dumped as heat.)

    And by the way, how old (time and cycles) is that "iPossible" cell? 5600mah of capacity is almost 17% below rated capacity, which is awfully close to the 20% capacity loss point where most manufacturers consider a cell "failed." I've got 100 charge cycles on my stock 3,200 mah cell and Accubattery still shows it as having 102% of factory capacity, and in fact it looks about that way every time I charge it -- right near 3,200ish. If each charge (to 80%) is ~0.4 cycles of stress then I should have consumed ~10% of the service life (~500 is the usual expected cycle life) by now, but it looks like I'm doing better than that.

    How are you doing with a cell that's already 17% below the rating on the label and what expectation do you have for the future number of cycles you can put on that battery?

    Maybe the reason I'm not burning up my battery cycle life is that I'm not letting the phone run the charge voltage up to 4.4V and hold it there for an extended period of time; I'm unplugging it before it gets there.....
    04-17-2018 05:26 PM
  13. Mooncatt's Avatar
    How are you doing with a cell that's already 17% below the rating on the label and what expectation do you have for the future number of cycles you can put on that battery?

    Maybe the reason I'm not burning up my battery cycle life is that I'm not letting the phone run the charge voltage up to 4.4V and hold it there for an extended period of time; I'm unplugging it before it gets there.....
    The iPossible battery is about a month or two old to me and has been at that capacity from the start. I suspect it's either an old cell from the manufacturing date or just not optimal quality. I already returned a Perfine (basically same thing but different label) that barely had 3,200mAh estimated capacity. Since this one lasts me long enough during the day, I'm not going to go through the exchange process again.

    My normal charging habits are to keep it between 40-80%. I only did the extended discharge/charge cycle this time to get the full staged charging pattern graphed to show.

    Fyi, I didn't expect it to charge as quick as the pen battery. I know the phone will charge at a max rate based on the OEM capacity, which is why I said in my last post that getting a full OEM charge in 3 hours would be reasonable and match up with your opinion of proper charging times. I was adjusting for capacity in that statement.
    04-17-2018 05:36 PM
  14. Mike Dee's Avatar
    I'm just going to live on the wild side and plug it in whenever I think I need more juice.
    04-18-2018 09:02 PM

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