Current Li-Ion chemistry is much improved from a few years ago, and self-discharge rates are a lot lower (hence the amount of charge left after 6 months).
It's fine to keep the battery in a drawer (cool/dry, of course) and charge every 6 months. They will probably last longer, but perhaps not for the reason you would expect. You also have to accept that you loose the advantage of the built-in UPS-like behavior of a laptop with a battery, but if you have an external UPS, you may be OK with that. For storage you actually want to partially discharge the battery (to 80%) before putting it away; Li-Ion has self-damaging chemistry at both 100% and 0% (whiskering and swell-cavitation), so you want to discharge to 80% before storing it, then charge back to 80% before it drops below 30% (typically 6-9 months, check it monthly to be on the safe side). Recent systems won't "cook" a battery, the charge circuits automatically avoid overcharge, but any (commonly available) Li-Ion kept at 100% charge for too long will develop internal shorts due to the whiskering effect of high charge separation combined with corrosive internal chemistry. Whiskering does take a rather long time, however, typically 3-5 years for good quality batteries. On 07/22/2012 09:12 AM, keith smith wrote: > > Sometime ago we discussed laptop battery life.� I asked the question about > leaving the battery out and if that would extend the life of the battery.� > I'm not sure that option was explored. > > Last December I took the battery out of my two lap tops.� I use both daily > for about 15 or 16 continuous hours. > > I have been thinking the batteries might be fully drained by now.� Much to my > surprise the newer laptop's battery was at 81% and the older laptop's battery > was at 58%. > > Both are taking a charge.� After they are fully charged I will put them back > in my desk drawer and charge them again in 3 to 6 months. > > I've have had poor performance from laptop batteries and did not want to > "cook" these.� It will be interesting to see if this extends the life of the > battery. > > Any thoughts? > > ------------------------ > > Keith Smith > > > > --------------------------------------------------- > PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us > To subscribe, unsubscribe, or to change your mail settings: > http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
signature.asc
Description: OpenPGP digital signature
--------------------------------------------------- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
