laptop plugged in still uses battery?

Post by **Tsakali_** » Sat Jul 28, 2007 4:59 am

does plugging into wall socket prolongs battery life? Should I plug in whenever possible and reserve using the battery only when necessary or does the laptop still takes power from battery via the wall socket?

Post by **R00k** » Sat Jul 28, 2007 5:16 am

no, plugging it in charges the battery even while you're using it.

but it can be bad for the battery life.

you shouldn't plug it in unless it needs charging.

Post by **Tsakali_** » Sat Jul 28, 2007 2:02 pm

ahh k, but see my question was about if the laptop bypasses the battery all together and just uses the juice straight from the wall, but you did give me the answer I was looking for :icon14:

Post by **SoM** » Sat Jul 28, 2007 3:20 pm

R00k wrote:no, plugging it in charges the battery even while you're using it.

but it can be bad for the battery life.

you shouldn't plug it in unless it needs charging.

so its better to remove the battery and then using the cord ?

Post by **Foo** » Sat Jul 28, 2007 5:41 pm

Yep. And depending on the battery type, leaving the battery charged or discharged will have different effects on its lifespan. Also running the battery down fully every day or keeping it topped up will have different effects too.

Post by **obsidian** » Sat Jul 28, 2007 8:19 pm

Most laptops use lithium-ion batteries and they have some very different properties than Ni-Cad or NiMH batteries. There is very little that you can do with regards to normal use to extend the lifecycle of the battery. Whether you use it or not, they last about 2-3 years.

Contrary to popular belief, full discharges can actually be harmful to Li-ions. Normal charging has little affect to overall lifecycle.

More info:

A lithium-ion battery provides 300-500 discharge/charge cycles. The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge the battery more often or use a larger battery. There is no concern of memory when applying unscheduled charges.

...A lithium-ion battery in use typically lasts between 2-3 years. The capacity loss manifests itself in increased internal resistance caused by oxidation. Eventually, the cell resistance reaches a point where the pack can no longer deliver the stored energy although the battery may still have ample charge.

...The speed by which lithium-ion ages is governed by temperature and state-of-charge... The worst condition is keeping a fully charged battery at elevated temperatures, which is the case with running laptop batteries. If used on main power, the battery inside a laptop will only last for 12-18 months. The voltage level to which the cells are charged also plays an important role to longevity. For safety reasons, most lithium-ion cannot exceed 4.20 volts per cell. While a higher voltage boosts capacity, the disadvantage is lower cycle life.

Removing the battery from the laptop when running on fixed power protects the battery from heat... The question is often asked, should the laptop be disconnected from the main when not in use? Under normal circumstances, it should not matter with lithium-ion. Once the battery is fully charged, no further charge is applied.

http://www.batteryuniversity.com/parttwo-34.htm

Post by **+JuggerNaut+** » Mon Jul 30, 2007 9:52 pm

back to the battery thing: my Dell C600's battery lasted for almost 5 years and the only time i unplugged was i absolutely had no outlet to use.