All I see is slightly more text. No authoritative sources or anything which would make your position more valid.
Even if one takes everything you just wrote at face value, you kinda made my point. The battery control circuit is, as you say, programmed specifically for the capacity the battery pack has when it leaves the factory. As the battery cells degrade, however, the capacity changes. Most modern battery packs are able to recalibrate themselves, but that requires a full charge/discharge cycle to work optimally. For some reason, you mix the concept of battery cells and battery packs willy-nilly in your argument. A battery pack consists of several battery cells and, for certain types of cells, a control circuit. This circuit manages the different flow direction requirements when charging/discharging (li-* cells cannot be charged in series, for instance), and if it senses that one or more cells have been too degraded or damaged to function safely, it simply kills the pack to avoid a more violent ending in the future. Now, with that important distinction in mind this time: I never said it is good for the battery CELLS to discharge completely; indeed, rechargeable li-ion and li-po battery cells are considered dead when the voltage across them has dipped below a certain level, although one can try to recover individual cells using various methods. I did say, however, and still say, for that matter, that the CONTROL CIRCUIT does its job better if it experiences a full cycle, since it then is able to measure how much the cells have degraded and readjust. If one does not do this, the battery will gradually start to report the wrong charge level. Doing this is still bad for the cells, though, which is why one shouldn't do this often. General consensus seems to be around once a month or once every two months. It's a trade-off, for sure, which is why I'm not really fond of li-*. We don't really have other alternatives today, though. Unless there has been some recent developments, of course. Has there? The fact that you want to charge li-* cells by "pulsing a DC current" through them makes it quite apparent that you don't really know much about these types of cells. One charges a li-ion cell first with a constant charge current, during which the voltage across the poles gradually increases to the nominal voltage according to spec. Then you keep charging at this voltage level until the current flow drop levels out. We use individual li-* cells in our lab at campus for various tests, and we often charge them with a lab cube and regulate voltage/current manually because one simply cannot be arsed to make/fetch a charger for a one-shot experiment, so I do have working experience with this. But if you do decide to try a hand at charging an unregulated cell with your, ah, "pulsing DC current", do send me a picture of your singed eyebrows afterwards! :) On 12 June 2012 19:07, Mike Barnard <[email protected]> wrote: > > On 12 June 2012 16:58, Benjamin Tayehanpour > <[email protected]>wrote: > >> None whatsoever. :) > > > There are authoritative sources on battery technologies and one that > requires you to frequently drain a battery is quite not there... or if it > is... may be out-dated. > > More recent batteries that carry with them control circuits do help one > ensure that the batteries are not drained beyond a cartain point. this is > to ensure that the point of no return is not reached quickly with a battery > as happens with frequent discharging and deep discharging. > > But logically it fits. A battery degrades over time, and the only way for >> a controller circuit to know the rate and extent of this degradation is by >> actual measurements when the battery discharges, and if it never >> discharges, no measurements can be made. >> >> > It is not required to completely drain batteries once in a while. This is > a myth, just as it is a myth that replacing the electrolyte in a battery > gives the battery a new life. Batteries all work by a chemical reaction > that takes place between two elements. the more you let these > chemicals/elements change from the active state to one that has reacted > with the chemical/element that causes current to be generated the faster > the battery dies. > > the more frequently you drain a battery, the more frequently you have to > charge it. This usually means the more often you force the > chemicals/elements back to their active state (or original state). this > charging wears out the chemical/element and is one of the reason one is > advised not to drain batteries beyond 50% of its capacity. > > Battery control circuits are usually designed for a specific make and > manufacture of a battery; which is why you are required to replace worn out > batteries with their specific model. You cannot use just any 12/18 volt > battery that fits your laptop. It wont charge in the required time or may > get over-charged or get under-charged. > > The battery control circuit for your laptop is designed specifically for > that battery designed for the device. The control circuits are, for lack of > better words, hard-coded with the battery specifics; charge method, battery > full voltage, battery float voltage, battery low voltage and current drains > for each. The 'charge sensors' actually follow these specific values that > are 'hard-coded' in the circuits to ensure that the charging current and > voltage are controlled accordingly. what it knows about the battery and > what it reads from the battery are what the control circuits use to tell > you how much battery capacity/time you have. > > Charging could then be either simple charging which is really pulsing a DC > current through the battery, trickle charging, time-based charging or what > our laptops have and many control circuits have, an > intelligent/smart-charger. > > > On 12 June 2012 16:37, Peter C. Ndikuwera <[email protected]> wrote: >> >>> On 12 June 2012 16:01, Benjamin Tayehanpour <[email protected] >>> > wrote: >>> >>>> >PS: the life span of a battery is determined by how frequently its >>>> discharged below its 50% capacity and how long it stays below that. if you >>>> want a >longer life out of your battery, keep it fully charged or if you >>>> cannot, then do not discharge it too low too frequently >>>> >>>> True to a certain extent, but not entirely. While it is correct that >>>> Li-ion and Li-Po batteries should not be discharged entirely on a frequent >>>> basis, the battery control circuits in a battery back will not let you do >>>> so, ever. When a laptop battery reports that it is "empty" it really means >>>> drawing more current would be fatal to the battery cells. >>>> >>>> That said, you still should not drain the pack often. But it is >>>> recommended that you fully drain it about once a month or so, to calibrate >>>> the charge sensors. >>> >>> >>> There's a lot of conflicting information out there. Including >>> information that the whole "battery calibration" thing is a myth. >>> >>> Any authoritative sources? >>> >>> _______________________________________________ >>> The Uganda Linux User Group: http://linux.or.ug >>> >>> Send messages to this mailing list by addressing e-mails to: >>> [email protected] >>> Mailing list archives: http://www.mail-archive.com/[email protected]/ >>> Mailing list settings: http://kym.net/mailman/listinfo/lug >>> To unsubscribe: http://kym.net/mailman/options/lug >>> >>> The Uganda LUG mailing list is generously hosted by INFOCOM: >>> http://www.infocom.co.ug/ >>> >>> The above comments and data are owned by whoever posted them (including >>> attachments if any). The mailing list host is not responsible for them in >>> any way. >>> >> >> >> _______________________________________________ >> The Uganda Linux User Group: http://linux.or.ug >> >> Send messages to this mailing list by addressing e-mails to: >> [email protected] >> Mailing list archives: http://www.mail-archive.com/[email protected]/ >> Mailing list settings: http://kym.net/mailman/listinfo/lug >> To unsubscribe: http://kym.net/mailman/options/lug >> >> The Uganda LUG mailing list is generously hosted by INFOCOM: >> http://www.infocom.co.ug/ >> >> The above comments and data are owned by whoever posted them (including >> attachments if any). The mailing list host is not responsible for them in >> any way. >> > > > > -- > Mike > > Of course, you might discount this possibility, but remember that one in a > million chances happen 99% of the time. > ------------------------------------------------------------ > > _______________________________________________ > The Uganda Linux User Group: http://linux.or.ug > > Send messages to this mailing list by addressing e-mails to: > [email protected] > Mailing list archives: http://www.mail-archive.com/[email protected]/ > Mailing list settings: http://kym.net/mailman/listinfo/lug > To unsubscribe: http://kym.net/mailman/options/lug > > The Uganda LUG mailing list is generously hosted by INFOCOM: > http://www.infocom.co.ug/ > > The above comments and data are owned by whoever posted them (including > attachments if any). The mailing list host is not responsible for them in > any way. >
_______________________________________________ The Uganda Linux User Group: http://linux.or.ug Send messages to this mailing list by addressing e-mails to: [email protected] Mailing list archives: http://www.mail-archive.com/[email protected]/ Mailing list settings: http://kym.net/mailman/listinfo/lug To unsubscribe: http://kym.net/mailman/options/lug The Uganda LUG mailing list is generously hosted by INFOCOM: http://www.infocom.co.ug/ The above comments and data are owned by whoever posted them (including attachments if any). The mailing list host is not responsible for them in any way.
