Battery load cycles

[SpringHeeledJack]

One's laptop battery has just gone through 200 load cycles and is down to 65% health. On taking it into the manufacturers to be checked I was informed that despite them giving the battery a life of 300+ load cycles before any degradation occurs my situation was not unusual and was probably caused by leaving it 'plugged in too long'…..I have to confess that nowhere in their bumpf was that mentioned, nor did I think that that would make such a difference otherwise I'd have seen it mentioned over the years. Is this really the case ?

My usage is tame by any standards, that is no energy sapping applications needing high amounts of processing power so it leaves me puzzled. Effectively to be true to the 300 load cycles the battery would have a life of approximately a year if it was to be used daily and kept away from the power cord


SHJ

[mixture]

How old is said battery ? I was under the impression that for modern batteries one should always favour top-up charging over the old fashioned full drain & restore.

[SpringHeeledJack]

It's 667 days old mr mixture although it's been in the laptop since the 600 day mark. All totally ok until a month ago and then a steady degradation of approx 35% since then despite recalibrating it. In general I've always top-up charged the battery more than complete drain and recharge.



SHJ

[llondel]

Lithium Ion batteries, if kept fully charged, lose about 10% of their capacity per year (numbers might have changed, but the principle is the same). If it's kept at 40% charged it'll lose a lot less of its capacity. Keeping them at elevated temperatures also degrades the internal chemistry, so if you've got a laptop that is kept on its charger a lot, and the battery pack gets warmed by the rest of the machine while the charger is on, it'll degrade the capacity. They also are rated for a number of full cycles, which can be made up from a set of smaller cycles (so discharging to 80% full and topping up to 100% five times is a full cycle of 100% charge). Given the degradation at 100%, deep cycling is probably better for the battery life than keeping it topped up.

Added to that is how good the batteries were in the first place - good brand names put a lot of effort in, cheap places, and what you may find on eBay, are going to be more of a lottery.

[mixture]

Are there perhaps any software updates for your laptop chips to do with power management ?

[SpringHeeledJack]

All updates that I know of have been updated mr mixture, I'm not aware of any changes to power management in any updates. I have been informed that the battery is faulty by a friend who works for said company, but that as it is over a year old the warranty is gone and the policy is to be less than generous I'm not trying to pull a fast one, but such a fall off in performance so soon in the spec seems a bit unfair.


SHJ