How long does it take to kill a new laptop's battery?

[DoYouKubuntu]

Every time I get a new laptop I PROMISE myself I won't kill its battery [by leaving it plugged in 24/7]. Unfortunately, though, I never seem to follow through. I always end up with a battery that cannot hold a charge, even for a split second. That's really NOT a big deal for me, because I use my laptop(s) at home--and since moving from Texas back to California, I rarely have to deal with power outages! But I'd still LIKE the option of running on battery. My latest laptop, which I've had for ~4 months, started out with me pulling its plug every day...then every other day...now a couple times a week... I've already noticed its charge time decreasing; it'll stay up for approximately 2-1/2 hours, and that's it.

So just how long DOES it take to kill a new laptop's battery? I've never actually timed it before...I've just gotten real good at killing them. If I stopped unplugging it at all, any ideas how long before its battery would be useless?

[lcorken]

Re: How long does it take to kill a new laptop's battery?

I have an old Fujitsu 2.8gig P4 CPU close to 10 years old. It stays plugged in nearly 24/7. The original battery is down to about 1/2 hour running Lubuntu now.
Don't know what normal is. I've heard many conflicting ideas about wheather it's best to keep it plugged in or not. Or if it's better to discharge occasionally?
Unfortunately these batteries are rather pricey.

Ken.

[ardvark71]

Re: How long does it take to kill a new laptop's battery?

So just how long DOES it take to kill a new laptop's battery?

The world may never know.

(Hint: Does anyone remember the tootsie pop commercial from 1969 with Mr. Owl?)

Regards...

[GreyGeek]

Re: How long does it take to kill a new laptop's battery?

I've read that if you charge your battery no higher than 80% and don't allow it to discharge below 10% it will last a long time. The battery in my 3.5 year old Sony is still giving the same time discharging to 10% that it gave when it was brand new.

This Acer 7739 charges the battery to 100%. The proc info shown is:

/proc/acpi/battery/BAT0$ cat info
present:         yes
design capacity:     48400 mWh
last full capacity:   45496 mWh
battery technology:   rechargeable
design voltage:     10800 mV
design capacity warning: 4510 mWh
design capacity low:   2255 mWh
cycle count:       0
capacity granularity 1: 484 mWh
capacity granularity 2: 484 mWh
model number:      AS10B31
serial number:       
battery type:      LIon
OEM info:        OEM

Unlike my Sony, which had circuity which limited the charge cycle to a maximum of 80%, this low end laptop does not. I am not sure that stuffing 38,720 into the "design capacity" memory variable would be read by the kernel or any circuitry which controls the charging, but I am going to test it to find out. Luckily, the battery monitor expresses capacities in percentages, so I only have to make sure I plug the power back in when the percentage drops to 10%. However, I would prefer that I don't have to manually control the 80% level.