I recently started looking at LiPo charger ICs for a project. Do you have any links to whitepapers etc on this 4V/70% charging threshold? The voltage during charge is higher than the cell voltage and will vary=20 by temp. How is the 4V determined... by temporarily disconnecting and=20 cooling it off? Or is there some mapping/compensation to correlate the=20 4V at a higher temp? Cheers, -Neil. On 5/29/2018 6:09 PM, Richard Prosser wrote: > An I have another phone with an annoying "feature". > If left on the charger it fully charges the battery, then stops charging > and runs the battery down. It will only recharge if the charger is > disconnected and then reconnected again. I wanted to use it as a webcam > but..... > > For best battery life it should be charged to about 4V/cell. This > corresponds to about 70% charge. Above this voltage the anode degrades. > Below this voltage and the cathode degrades (so I'm told). > If you have control of the inner workings of the charger you could try > resetting the voltage to ~4V/cell (4V ?) and just leave it plugged in. > > RP > > > > On 30 May 2018 at 09:08, James Cameron wrote: > >> In my experience it depends on the phone DC input, usually under >> firmware control. >> >> Measure current over time on the DC input to document behaviour. >> >> Some phones reach charged state and disconnect the DC input, then draw >> almost no current until either battery voltage falls, or estimated >> state of charge falls below something like 90% or 95%, then they >> reconnect until charged. >> >> Some phones reach charged state and disconnect the battery, operating >> from the DC input until the DC input is removed. Of these, some won't >> track estimated state of charge during the self-discharge phase, and >> some will. >> >> One device I have goes one step further; if you leave it connected for >> a week, it presumes you plan to leave it connected forever, and says >> so; it disconnects the DC input until estimated state of charge >> reaches 50%, then transfers the load to the DC input. >> >> Thus it entirely defeats the idea of keeping the device _ready_ for >> use on battery in this way. >> >> -- >> James Cameron >> http://quozl.netrek.org/ >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .