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Optimizing Battery Health for Surface Pro (2)

mizzao

New Member
I've owned a Surface Pro for a few months, and the Surface Pro 2 for a week. Because they have non-replaceable batteries, I've been concerned about battery health - that is, maintaining battery capacity over the long term. It's well known that lithium-ion batteries experience loss of capacity through charge/discharge cycles, but also from being stored in high-temperature or fully-charged states. (See this post for details.)

For this reason, many laptop manufacturers have provided utilities to optimize battery health in exchange for giving up some immediate capacity:

  • Sony Battery Care software, which allows for 50% and 80% charging thresholds designed for AC and battery use, respectively.
  • Lenovo Energy Management software, which not only sets a single charging threshold, but allows the battery to cycle between multiple thresholds to avoid top-off cycles.

These are remarkable because the batteries in those laptops can be replaced, but the option still exists to optimize its life. However, the battery in the Surface Pro 2 can't, so this issue really needs to be addressed. After searching around a lot, I haven't been able to find a solution for the Surface Pro and Windows 8 despite putting a bounty on superuser.com.

I've come to the realization that having a solution to this requires firmware support from Microsoft (so that the charging policy can be implemented even when the Surface is powered off) as well as software support. I really would like my Surface Pro 2 to not have its battery capacity cut by half in 3 years due to poor energy management, and given its 8+ hour battery life right now, I'd love to sacrifice some of its immediate capacity for longevity.

I'm currently implementing the poor man's solution to this, which is to pull out the AC adapter whenever it reaches 80% charge. However, this is suboptimal because if I want to use it while docked, it either has to be charging or discharging (not just "not charging" but using AC power) and this causes unnecessary charge/discharge cycles on the battery.

What do you guys think is the best way to get an energy management firmware update to show up in this official list?
 
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PandaSPUR

New Member
I agree with you, I used this feature on my old Thinkpad T410. It would only charge when below 80% and stop charging once it gets to 95%.
It also ran directly off AC power when the battery was done charging, rather than drain from battery and top off battery. Not sure if SP2 does this.

Its almost 4 years old now and the stats show it still has 90% of original capacity.

Not sure how we can go about suggesting this though. I also read that to implement this, there must be hardware support as well :\
 

GypsyMoth

New Member
Personally, ensuring the lifecycle of the battery was the primary reason I purchased Microsoft's complete care. Shortly before I hit the end of the two year coverage I'll complain the battery is not maintaining a charge and request a replacement... I told the folks whom I purchased the complete care at the local Microsoft Store that this was my plan when I purchased it... I'd love to have utilities on the system that help lengthen the useful life of the battery, currently I keep the battery over 50% charted and run it down below 80% and completely recharge only once a month or less.
 
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mizzao

New Member
I think it is entirely possible that the SP actually does this invisibly in firmware

I don't think so, because it charges to 100% every time it's plugged in and one can see that.

The "What's new in Surface Pro 2" post contains the following quote, although I don't know if it refers to what you said above or is just marketing mumbo-jumbo. I'd like more details.

The Surface Pro battery is a long-life component designed to meet more than 1200 full charge and discharge cycles, and the embedded firmware manages the battery charging to avoid shallow ‘topping off cycles’, which can have a negative effect on long term battery capacity.

Is there somewhere we can poke Microsoft for this feature? Knowing how slow they move though, it's probably not going to make it out as a firmware update...
 
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