Laptop Plugged In, Would It Use Battery?

Hi. There has always been debate on whether removing the battery would help battery life. My thought has always been that if I plugged in my battery while the AC adapter is on, then the computer will use battery as well as AC power, and anytime the laptop drains from the battery, it will reduce its cycle.

So my question is, does the computer use the battery if the AC adapter is plugged in?

This isn't a question of whether the AC adapter continue to charge the battery, I know it stops when it is full, but it will recharge again when it is at 99%. So what about that? Wouldn't it infinitely keep it at 100% the second it drops to 99%? Does that affect batter life too?

Thank you.

 

1. The laptop on AC power only uses AC power.

2. Once the battery is charged to 100%, it is no longer charged unless you restart the system or take it off AC power. The charge will very slowly go down on its own, but the laptop will continue to say it is at 100% even though it is not. As soon as you restart or take it off AC power, the correct charge level will show up immediately. (Although I'm not sure if ALL laptops behave like this.)

 

you are overthinking the situation without knowing how the technology works.....

 

Wow, thanks Trottel. That was super informative. If that is really the case, then I can see no cons of plugging in the AC adapter besides heat. Newsposter, I'm not exactly sure how it worked, so I asked.

 

some laptops are a little smarter about how the recharge - they don't perpetually trickle charge, but instead wait for the reported power level to drop to, say, 95% or so, then charge back up to 100%. the fact of leaving the ac adapter plugged in doesnt really cause extra heat, so much as the fact that all the processors in the computer are more likely to run at full or close to full speed on ac power instead of half on battery.

 

No laptops trickle charge. Doing so would kill the batteries very quickly, often with fireworks, a property inherent to the lithium-ion design.

Any laptop can run at full speed regardless of power source depending on how you set it up.

 

Bleh, oversimplified it. I meant it won't constantly charge 99 -> 100.

And yes, they run at full if you set it up that way, but many people choose to leave the default settings, which power down the processor and mechanical drives to conserve battery life. He mentioned heat, so I assumed he didn't mean that the adapter gets warm.

 

Very informative. Thank you guys. Would you guys also mind taking a look at my laptop comparison thread?

Comparing the G62T vs DV6T

 

The advantage of leaving the battery in is when the AC power is cut. This acts like an external UPS saving your data and hardware. In the case like Asus charging at the 95% mark this lowers battery wear by not constantly top charging the battery.

If you leave the battery in, and system pluged in even with the laptop off the battery is still getting hit occasionally by the top charge. This is the reason alot of people pull them as it usually will extend the battery life somewhat. You have to decide if the inconvenience of putting the battery in and out is worth it compared to the power constraints of not having your semi built in UPS.

Remember though this is not a true UPS and there is little to no spike protection or brownout protection either. So having the battery in is not a substitue for a good UPS. Also not having the battery in can expose the connections to the enviorment too. connections can get dirty and/or corroded more easily.

Myself I rarely run off battery but leave the battery plugged in. Yes I will buy batteries more often but I'd rather do that than deal with the problems and hastle..........