Is there a way to tell the laptop battery when to stop charging?

5

I don't want my laptop's battery to always be at 100% because it lessens battery life, especially when above 25 Celcius, the lowest summer temperature in Israel (currently 30C - 32C). I prefer to keep the battery level between 30% and 50% and use it instead of a backup UPS battery. Is there any software that can do that?

If there is no software, can I wait until the battery reaches 100% charge, pull out the power cord and work in battery mode until it reaches 10% so Windows 7 will let me know or will automatically hibernate? Moreover, the battery can protect against brownouts and power outages.

Will having the battery with the power cord plugged in degrade battery life faster than unplugged? Would I be better using UPS? Will UPS be cheaper over the long-term compared to a laptop battery?

I have Lenovo G560.

Boris_yo

Posted 2011-07-13T09:07:28.317

Reputation: 5 238

Answers

5

It is true that keeping it plugged in all the time will usually shorten battery life unless you take measures to control the charging cycle. Manually unplugging it & draining the battery down periodically (e.g., every couple of weeks) can help to extend the life.

EDIT 2017-03-06. In the years since the above was written, some things have changed in battery technology. It is no longer recommended to put your battery through a full drain-charge cycle every couple weeks. A "calibration cycle" is recommended for some batteries every three months. See more info here. --- END EDIT

On my Lenovo ThinkPad I use the ThinkVantage Power Manager to control the charging process. Other manufacturers may provide a similar utility. (If there is a way to do it natively in Win7, I'd like to hear about it.)

In ThinkVantage Power Manager, switch to Advanced mode. Click the Battery Tab. Press the Battery Maintenance button.

screen capture

It's pretty self-explanatory - you can adjust the options there to get what you want.

yosh m

Posted 2011-07-13T09:07:28.317

Reputation: 2 048

1"Manually unplugging it & draining the battery down periodically (e.g., every couple of weeks) can help to extend the life." Do you know of any objective evidence of this? I don't; I know only of unsupported claims on dodgy sites like the so-called "Battery University". What is certain is that each such cycle uses a bit of the battery's life. And if the conditions are such that the battery stays at 25C, a few hours in a charge cycle every few weeks are not going to help much. Keeping it at around 60% will extend the life - that is how they're stored and shipped after manufacture. – Jamie Hanrahan – 2017-03-05T16:49:47.323

@JamieHanrahan - thanks for your note. I checked and Lifehacker agrees with you (more of less), along with sources they cite. See http://lifehacker.com/smartphone-battery-myths-explained-1735327089 . I will edit my answer (which was written at a time when that may still have been true...).

– yosh m – 2017-03-06T18:41:42.730

The basics of li-ion chemistry haven't changed that much. Deep discharge (to the "machine cuts off to avoid getting the battery into the point-of-no-return range" point) is not good for li-ions. Advice to do deep discharge persists from the NiCd days and even then it should only be done if the battery shows signs of voltage depression... which it will not with a smart charger. – Jamie Hanrahan – 2017-03-06T19:31:03.413

1I know that older type Ni-Cd needed to perform the charge-discharge-charge again cycle to keep optimal state and capacity. However, I was told that new Li-ion and Li-pol batteries do not require it and that intentional draining of the battery can even have negative influence on it. – Juhele – 2011-07-13T09:41:55.490

@Juhele And i heard that Lithium Polymer batteries have a chance of exploding. – Boris_yo – 2011-07-13T09:55:18.527

@yosh m Thanks. I have lenovo G560. Do you know if lenovo provide such utility for my laptop? Do you know how to contact them? – Boris_yo – 2011-07-13T09:58:15.997

@Boris_yo - yes, I know. This can happen in case of impact or battery case perforating. According to my information, this was a problem mainly of the akkus in solid metal casing which allowed temperature and pressure to increase and later led to explosion. Now, the main case is mostly soft plastic so the gas products of the chemical reaction can go out freely without explosion. – Juhele – 2011-07-13T10:11:17.460

1@Boris_yo - in addition, this was also mainly problem of cheap Chinese akkus without electronic protection - I remember the case about the fake Nokia cellphone akkus, originally some very poor quality ones from China. These could explode during charging or even when simply using the phone. – Juhele – 2011-07-13T10:14:28.147

@Boris_yo - Sorry, I don't know, but I suspect a simple search of the support pages for your model on the Lenovo site will locate the utility for you. they usually have downloads of all the relevant software. – yosh m – 2011-08-03T14:08:48.483

1

Accepted answer is for Lenovo, but the original question did not mention specific device brand. Original poster undisclosed his laptop type later. The general answer to original question is:

There is no universal tool, support depends on particular manufacturer.

Reason: design of charger circuits and their ability to limit charging is dependent on device manufacturer.

Some, like Lenovo or Dell are consistently seen to support charge level limitation across their models. Utillity to control charging circuits is included in pre-installed toolset or can be downloaded from their website.

Other manufacturers, like Apple, are not seen with any support of this feature.

You can always confirm this for your laptop brand by searching, for example

ASUS limit battery charging

miroxlav

Posted 2011-07-13T09:07:28.317

Reputation: 9 376