To fully charge or to keep drained, that is the question? (Battery that is)

[Isendar]

I have the M18x laptop (Angels begin to chant!). But before I got it I did some research on laptop batteries. Common sense dictates that all batteries will eventually lose their ability to hold a charge, slowly (hopefully), and eventually need to be replaced (years...). As such, I planned to originally remove the M18x battery and run it directly off the power charger. Unfortunately I didn't like the fact that there'd be a huge gaping hole in the bottom of my case where the battery was. Dust and other contaminents could invade and I just see that as all bad. I did more research on the bios program for the M18x motherboard and discovered the ability to change the batteries behavior. I changed this to Disabled (Do Not Charge). I did this to save the battery for when I actually need it and to increase its life expentancy. So here's my question:

Is it better to leave the battery fully charged, or to let it be completely dead? Which one would be worse/lessen the charging capacity over-time?

[vesseblah]

You should leave modern LiIon batteries charged in long term storage, and every half year or so use it empty (until the laptop force shutdowns), recharge, use it empty, recharge and turn charging off again for next 6 months.

[Isendar]

Vesseblah - Interesting although I just read an interview with a top researcher in battery technology who understands laptop batteries. He stated that it was best to remove the battery and keep it charged between 40 and 80%. Supposedly keeping it fully charge can wear down the battery faster than having say a half charge. Also he said that no matter what, even if you kept the battery in a room temperature drawer for 5-6 years, that battery would not work, whether it was fully charged, half charged, or dead. Kinda sad, but probably true. The reasoning behind removing the battery is due to heat. He claims that heat is the natural enemy of batteries and kills them faster than ever. Oh and on your suggestion for emptying and recharging, he said that most modern laptop batteries don't need to be emptied and then recharged except when the computer starts registering the charge % @ 20-30 and it dies shortly after even tho you had more time. The computer's battery charge sensor is off and in order to reset the proper %, you must drain the battery until dead, then recharge it. Then the laptop should be able to read the battery more accurately. He goes on to say that unfortunately by doing that, the battery dies much quicker, but then again, that's inevitable!

[Djinni]

To be honest, your going to get ALOT of conflicting data. And data about this (like alot of things) found via the internet should NOT be considered accurate without a recent date-stamp (within 2-3years)

Generally if you have the option to bypass the battery when you don't need it, then do it. You 100% want to avoid OVERCHARGING the battery. I find it best to occasionally run down the battery as far as you can, (IE keep booting the machine, leaving it on untill it dies.)

No matter how you store your battery when not in use it will eventually degrade.. The best you can really do is to make sure that you don't help this process by overcharging and therefore "overheating" it.

While I don't agree with Vesseblah about leaving it charged... I can't disprove his point. I believe you should always fully discharge it when storing it for a long period of time. (1+ months) So like I said above.... your going to find alot of conflicting viewpoints.

[vesseblah]

Point was...

Li-Ion batteries lose some charge over time, faster when full, but slower when it becomes emptier... If you let it run completely empty (~12 months) it becomes useless paperweight. If you store it charged (90%) or half-full (40-80%) doesn't really make big difference. It still loses bit of charge and dies in a year or so.

Two important things are to never store it empty (because then it will drain to levels that can no longer be charged again) and recharge it every 4-8 months to prevent it from ever running completely empty. The rest is mostly semantics and vary between manufacturers of the battery cells.

And yes, it should be stored in dry place with temp between 10-30C and the heat of the laptop will reduce it's lifetime, but you already said you don't want to do it for aesthetic reasons so I didn't bother arguing it.

[haxartus]

Point was...

Li-Ion batteries lose some charge over time, faster when full, but slower when it becomes emptier... If you let it run completely empty (~12 months) it becomes useless paperweight. If you store it charged (90%) or half-full (40-80%) doesn't really make big difference. It still loses bit of charge and dies in a year or so.

Two important things are to never store it empty (because then it will drain to levels that can no longer be charged again) and recharge it every 4-8 months to prevent it from ever running completely empty. The rest is mostly semantics and vary between manufacturers of the battery cells.

And yes, it should be stored in dry place with temp between 10-30C and the heat of the laptop will reduce it's lifetime, but you already said you don't want to do it for aesthetic reasons so I didn't bother arguing it.

That is correct, they die if you leave them completely discharged for a long time. Personally tested.

[nwo]

When I use the battery lifetime optimization feature on my laptop, it only charges it up to 80%. Therefore, it might be true that if you want to maximize your battery's lifespan you should keep it below 80% charge.

[vesseblah]

When I use the battery lifetime optimization feature on my laptop, it only charges it up to 80%. Therefore, it might be true that if you want to maximize your battery's lifespan you should keep it below 80% charge.

Li-Ion batteries never actually run completely empty or completely full in normal use, the charger should stop when the battery is 80-90% full and computer will automatically shut down when there's still around 30% charge left. Windows adjusts the 0-100% scale to those numbers. Could be on some laptops the normal operating temperature is so high that the software cuts charging earlier to prevent any problems that comes with heat while charging the batteries.