I bought a Thinkpad E450 from Amazon last year. First day I plugged it in, the battery died. I had a battery replacement which after a month started failing, and more recently, another battery replacement.

After that I've been using the laptop for almost 3 months without any issue, but when I checked the battery status I got:

Battery 0: Discharging, 53%, 01:31:19 remaining

Battery 0: design capacity 4119 mAh, last full capacity 3841 mAh = 93%

A month ago the last full capacity was around 97%. I'm afraid to have another issue with the battery, and the warranty is about to expire.

Is the full capacity decrease to 93% normal for a 3-month old battery or should I should take the laptop in for service again?

battery details screenshot

  • Lion Batteries decline in capacity every time they are charged, its a slow death. – Moab Feb 8 '16 at 22:52
  • They also last longest if charged to ~80% and never discharged below ~20%. Following this duty cycle, of course, means that you use only ~60% of the battery's full capacity (run time). – DrMoishe Pippik Feb 8 '16 at 23:07
  • 2
    Are you doing anything special to extend the battery life? Because most of the advice you see is obsolete and based on battery technologies that haven't been use for more than a decade. – David Schwartz Feb 8 '16 at 23:20
  • We need more information. Cycle count would be most helpful. – Hefewe1zen Feb 8 '16 at 23:40
  • @Hefewe1zen just added a screenshot with more details – nailujed Feb 9 '16 at 0:28

Battery cycles tell you how often the battery has been discharged/recharged. Some manufacturers will say that after 300 cycles it should keep about 80% of the original capacity. Obviously this is not written in stone, but a general guide.

Applying this formula--from your screenshot, you've used 39 cycles out of 300--which is 13% of the way to a theoretical 80% max charge. I would say that the battery is operating normally. (Also, please keep in mind that capacity vs cycle count isn't quite a linear graph, it has a slight curve to it.)

Best practices? Keep your battery within its recommend temperature range. Don't discharge it all the way to zero, if at all possible. Extending your battery life by adjusting power save settings (e.g., cpu throttling, display brightness, etc) will give you a longer burn for each cycle. Only use the battery when you need to. Make sure you're using the right charger.

  • I think you might have gotten the capacity loss backwards. The most common information on the net is that batteries retain 80% of the design capacity after ~300 cycles. It most certainly isn’t supposed to end up at a mere 20%. – Daniel B Feb 16 '16 at 12:27
  • Thank you for pointing out the typo. I should also point out that the 80% cycle count varies by manufacturer. For example newer Macbook Pros have a 80% 1000 cycle count limit. The OP will have to contact Lenovo to find this out. – Hefewe1zen Feb 16 '16 at 21:01

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