It's kind of like a printer trying to estimate how much ink is left based on how many pages you've printed since installing the new cartridge. This process will shorten the overall life of the battery, but once a month should not affect it significantly. However, in response to your question about what's better for the battery, I think maybe it's best to have it plugged in while you're using it the heaviest. Can i use a charger with 12v and 1.5A max to charge the whole pack?? All alerting targets respond with a data bytes containing their own address. I own a Htc Sensation XE, So as u said that 4.2V to charge the battery, But why the original htc charger output was 5V___1A ??? To Ryan: Your battery is your buffer. Vince. That is, the phone is using energy as fast as the power cord is supplying it, and the amount going to or from the battery is minimal, so I'm not subjecting the battery to any charging cycles. The charge circuit is straight forward; voltage and current limitations are easier to accommodate than analyzing complex voltage signatures, which change as the battery ages. A shunt resistor, which has been connected in parallel across the filament before it burnt out, will then short out to bypass the burnt filament and allow the (If target transmitting to controller) The controller wishes the transfer to stop after this data byte. I occasionally salvage discarded Li-ion laptop battery packsdisassembling them to harvest the 18650's for personal r/c and flashlight use. The trip threshold then drops down to 2.7A after the inrush current has subsided. The PWM fans are commonly seen as CPU coolers with higher power consumption. Besides, how could you connect that to your battery? I was not aware of the need of a BMS when I started my project. I am wondering how will the charge current be divided among the batteries. i'll be back at you in the future, i am sure. My comments on the above are that these are not very practical. You say "A device should be turned off while charging. and would this damage the battery? Will the entire pack balance itself if given time to "rest" after charging to 4.0 volts per cell? does it highly affect cycle life? To charge it all night (8 hours) ? In fact, it is better not to fully charge because a high voltage stresses the battery. Please, translate to portuguese Brazil. The PWM signal can start or stop the motor, depending on the high and low state of it. CXR PS don't be a stranger , if you find something you feel may help me send me an email ! No idea. ), Li-Ion (Poli)bat Min V=2.7V ? I am using old 18650 cells from laptop computers hocked up in series to get 37.80 volts to run a 9 Led flush light. I wonder how many amps have to take the charger to extend the useful life of the battery, if low amp (500mA, for example), or a high amperage (1A-2A). Hi i wondered when you charge a battery with a charger can it ever read more then 4.20 volt on a multi meter ? Plz help.. @ Flynn Siy, the ratings of the charger mentioned misguiding me as the standard charger rating should be in terms of volts and Amps/milli amps(mA) but not in mAh. it came with a usb charger that plugs into wall socket and reads SEC: 3.7v ::: 350mA. I now know how to properly charge a 3.7 volt Li-Ion pack I took out of a Blackberry phone that is since defunct. Joe M, @ TERENCE MORRIS, It sounds like you either have defective batteries, or you purchased a 3rd party battery. Anything over 4v is pretty full, and anything under 3.4v is pretty low. 4. PWM vs. DC Fans: Fan Speed Control Strategies for CPU Cooling and Case Ventilation. Learn more about Bluetooth operation, functionality, and applications as well as our design tips for creating Bluetooth PCBs. The best suggestion I can give you is about your practice #3. Plz share contact no, I am working on a way to recharge the batteries in a transponder or 2. This is a great site !!! Learn about Joule heating, its applications, and Joules heating formula in this brief article. You need to purchase new batteries. So, basically i just want to make sure my method is basically correct. I works well and I have tested it several times. I know the charger circuit is in the laptopIt's just the name we usually give to it. If I keep the pack to mid-range capacity use (being conservative in both charge cutoff and discharge cutoff) can I get away without one? 4.20 400+ capacity 80% 4.25 400 bat capacity 25% 4.3v 250 Cycles 50% 4.35v 190 Cycles 25%, Higher charge voltages boost capacity but lower cycle life and compromise safety. Post back here if you've found any. I've got a pair of 18650s I've been carrying as spares. What can be used to measure the drop in current and switch off the supply of power to a 5v power supply. My HTC EVO cellphone shuts down when the discharge voltage reaches 3.6 volts. They are supplied with DC power. What would be bad about using a dumb 4.2VDC (800mA) charger to charge a single, protected cell, instead of a smart charger with intelligent charge termination? charger socket on my Google Mobile has expanded and not retaining charger plug which keeps dropping off, can I replace Mobile socket ? I have an old charger that is rated 19V, 3.4A and 65W. I really like your page. do batteries need to be completely depleted before charging? Good chargers will shut down or current limit but cheap ones may overload and heat up to the point of meltdown. Michael, NO, the manufacturer recommends that when 4.2 v is reached, let the current fall to c/10 then turn it OFF. thanks for any help :). A smartphone, for example, may have a minimum voltage at which the phone will shut down and won't come back "on". So even its safe to constantly keep the battery at full charge the rate of deterioration of battery is higher compared to keeping the battery at about 40% charged. These are bad ideas, and nobody but you will be responsible for the consequences. The problem is that when swapping the batteries Android Marshmallow always shows the same percentage for the new battery as for the old. I wanted to restart the process this morning, to finish the charge, but impossible. This app called ace charge, it disconnect the charge on 100% full charge or even can define to not charge the phone over 80%! Cameras are high-drain devices, meaning that they require more current than other devices. Vince. 1/4: Jerry Jones: Apple suggests doing a full discharge/full charge cycle once a month to calibrate the percentage of battery life indicator. To zz: we are not in a perfect world. According to http://en.wikipedia.org/wiki/Lithium-ion_battery, charge efficiency of Lithium-Ion batteries is typically in the 80% to 90% range. If the solar power is fed directly into the phone without regulation, and the voltage varies, then it could reduce the life of the batteries (or more likely damage the phone). Do you think that is just superficial as in it's a calibration thing or do you believe it actually might increase/reach the full potential capacity by doing such initial cycles? Charge moves from higher voltage to lower voltage. How do you know its' "empty"? Charging lithium-ion batteries is simpler than nickel-based systems. Is it available ? This could be due to the protection circuit and/or elevated internal resistance. I am interested in buying Li-ion 9v batteries but was taken aback by the large numbers of Amazon users that ended up with dead batteries from allowing the voltage to drop too low. Some lower-cost consumer chargers may use the simplified charge-and-run method that charges a lithium-ion battery in one hour or less without going to the Stage 2 saturation charge. The students will gain an appreciation for the magnitude of the opioid overdose epidemic as well as an understanding of how first responders can intervene with Narcan to prevent mortality. @vince yeah I agree it be a great science experiment and would help to answer some unaswered questions from doubters and limit the debates whether charging discharging initially improves the battery capacity. When you say "Discontinue using charger and/or battery if the battery gets excessively warm", what is the temperature range you should discontinue charging? The reason I ask is for DIY EV applications the cost of the BMS is very expensive, and if the voltage was doubled with the same amps, the cost of BMS would be much less, half the cells to monitor. Should I use PWM Solar Charge controller to charge Li-ion Battery. And when you drain the pan, that corner will drain first, while most of the rest of the pan still has a lot of goo in it. The capacity trails the charge voltage like lifting a heavy weight with a rubber band. Because it's not a linear transition, I think your 85% goal might even be achieved at 3.9V. They've been married since day 1. could you any one can tell about how the lithium ion battery full cell making ? Thank you for the article! Unless you left something out, I'm not sure how a 5.2v charger would apply to any Li-ion battery. Thanks. When the target successfully transmits its own address (winning arbitration against others) it stops raising that interrupt. Right now I'm eating a pizza, and soon I'll decide I'm full. I took a best guess at the LG cells that died and loks like all is great. Cells are the 18650 type found in laptops. We have been leaving it plugged in most days, then unplug it at night. The speed control of cooling fans is a much-debated topic and PWM fans and DC fans are the most frequently discussed solutions. thank's Vince for your fast answer ! This eases the voltage stress. the only harm is that Lithium batteries don't like highest and lowest allowed voltage level. I have two choices for the charger, 750mA or 1200mA and I've been thinking about that which one is better in the long run? For example, if I'm driving down the road using it for GPS with the screen on, that requires a lot of power, so I have it plugged in during that time. A portable device should be turned off during charge. Hi there! I was told the battery has a memory. hmmm. need to do more research. But after I wait a while and let things settle, I'll have room again for a little more. When it gets close to empty, you really have to be patient to get the last few drops out. What can be the problem? Learn how Ka-band power amplifiers convert signals to improve satellite communication quality. Well, I guess modern times are more practical. Which should I believe, the manufactures's manual or this article? According to the first chart at the top of the page, batteries can be considered full when the charging current falls to 3% of C, or about 0.1A in your case. THX, right marsman, in fact they went in overvoltage, i've used a charge holder for car battery with a resistive load to have the right voltage drop (near 2.5 V) and when the current fell down, the drop had diminished so at the end my barrery was at nearly 13.6 !!! Lithium-ion operates safely within the designated operating voltages; however, the battery becomes unstable if inadvertently charged to a higher than specified voltage. Is a BMS VERY necessary? The unit will not turn on with these batteries. Now here's another thing to consider with extended batteries: The hone might pump a full normal battery's worth of charge into it, and read "full", even though the extended battery can actually hold much more.