How to prolong lithium-based batteries

This is the most useful article I’ve read in ages. The whole Battery University site is great, but this page in particular is pure gold.

Dave’s laptop battery is fried… just over a year old, and it only lasts about 20 minutes. My little Acer TabletPC has two 2-hour batteries, and I’ve just realised that the info I got from Acer about how to look after them is bad, bad, bad, and I’m gonna have to change my usage habits if I want to get the full 2 – 3 years out of ’em.

If you can’t be bothered reading the whole article, here’s the important summary:

• Don’t leave your laptop plugged in to AC power with a fully charged battery. It’s the heat that kills ’em, so don’t leave them in hot cars either.
• If you’re not using them, it’s best to store batteries at about 40% charge, and as cool as possible. Never store them for long periods completely discharged or they might not recharge at all.
• It’s better not to fully discharge lithium-ion batteries – power “top-ups” don’t hurt them as they don’t have memory like nickel batteries. However, if you never fully discharge the battery, the “power remaining” gauge becomes inaccurate. A full discharge every 30 or so charges will take care of that.

Hmm… I’m off now to label my two batteries and start keeping track of each charge/discharge. There’s nothing worse than running out of power when you’re no where near a power point!

I can’t help thinking that in 10 years time I’ll be telling stories about how we used to have laptops that only lasted three hours. Give the kids something to laugh about.