Optimize battery lifespan option

[Sandeep]

Binary package hint: gnome-power-manager

This is an enhancement request.

Based on lenovo power manager, the options are

*Always fully charged *: Select this setting to always be charging your battery on AC mode. I don't recommend this - this is the setting in Linux.

*Optimize for battery lifespan (automatically change for me)*: I still do not understand this setting. Right now, it seems to not charge the battery unless it gets under 96% charge, and then it charges to full. Its language implies that it changes that charge level based off of a good compromise between battery life and charge.

*Custom*: I recommend this. Following the Battery Guide, I set my battery to Start charging when below 20% and to Stop charging at 40%.

This is extremely useful and essential to prolong battery life: http://www.apple.com/batteries/

[lavinog (lavinog)]

The 40% limit is for if you plan to store your battery. I would not recomend operating a portable device at such a low capacity.
Most manufactures seem to agree that charging a battery to the full capacity can reduce the life expectancy of the battery, but this seems to be in 80-95% area.

Should software override the manufacturer's implementation?

[Sandeep (sandys-gmail)]

@lavinog - I agree on your assertion that it is counterintuitive to keep a battery at low capacity for a portable device. Which is why I think having "profiles" is a good alternative.

By default, let it operate as it is doing now - charge always. However, a lot of people use their laptops as desktop replacements and it makes sense for them to choose a "optimize battery lifespan - battery will not be fully charged" option.

As I have read on many sites, even charging batteries only when they fall below 90% is far better than continuous charging. A 90% charge is still a very acceptable number for portable devices.

Profile-based battery charging gives one the flexibility to tune your system to maximize battery lifespan.

[AmenophisIII (amenophisiii)]

for lenovo thinkpads the low level infrastructure for this request is already in ubuntu in the form of a sysfs interface (tp-smapi-dkms package in lucid).
http://www.thinkwiki.org/wiki/Tp_smapi#Battery_charge_control_features

what about other hardware?

[Maciej Warnecki (maciekw5)]

I'd love to see this functionality implemented for more than just ThinkPads!