Should I use my notebook the same way I use my phone, i.e., usually on battery power?

(DISCLAIMER #1: Inspired by grude’sother battery thread, which I thought I’d be hijacking if brought this aspect of the matter up there.

DISCLAIMER #2: Long, detailed OP, at times straying into side issues and reminiscent of the doomed Scott party’s quest for South Pole, at the point when individuals start wandering out of the tent and not bothering to come back. If desired, you can scroll down to the bolded “Recently, …” and start reading there. The first couple of paragraphs are just illustrative background info.)

If you think about the way you use your phone, you’re obviously going to be using it on battery power nearly all the time, otherwise it wouldn’t be much use as a mobile phone. I’m currently on my fourth smart phone, and they have all held up well under this type of use. Each day, I use my phone fairly heavily, doing all the usual things one does with a smart phone–picture taking, browsing, streaming lots of audio but occasionally video too, playing stored media, FB, etc., etc., etc.–and, oh yeah, once in a while I take or make a call. I rarely drain the battery below 60%, unless I have to be away from the house all day, and every night I recharge it back to 100%.

In the past, I’ve read that you should not charge a notebook battery more often than you need to, and that you should never overcharge a notebook battery, and so on, but you should nevertheless mostly discharge it, and generally not fully charge it at all, let alone overcharge it, to get the longest possible life out of it. It was almost as if you’re supposed to keep the charge level between 20% and 80%. Or was that 15% and 87%? And, for calibration purposes, at least once a month fully charge and discharge the battery. In short, you must treat your battery with all the tender care you would a dandelion puffball, if your life depended on said puffball and it were a good day for flying a kite. Oh yes, and also use the battery like you would a flashlight, i.e. the less you use it, the longer it lasts–so you shouldn’t use it except when absolutely necessar. Apart from the guidelines about periodic partial discha…arrrghh, you get the idea. But it was back in 2009-10 that I read all this.

Anecdotally, my experience seems to bear that out. In our house we have three old laptops which still work, but their batteries are completely shot, and at least two of the batteries in those computers have been overcharged. I replaced the battery in one of them, but that’s basically shot as well. After all, they are old computers and I wouldn’t have expected the batteries to last this long anyway. Long story short, you can’t use any of those computers without being plugged in.

Recently we both got new computers, both the same model. They have several times the RAM, at least 40% more disk space (depending on which old computer is compared to them), and much faster processors, and much less weight; in short they are a joy to use. In both new computers, too, the batteries seem to be quite robust, holding a charge well and being slow to discharge even during fairly heavy use. The only minor niticky complaint I have is that the power cord is too short. In my case, sitting on the left side of the bed where I usually use the computer, the power strip is on the wall behind me and a little to my left. The receptacle on the computer is on the right side, so the cord must lie across my lap. Even though the power strip hangs between the bed and my nightstand, the entire cord hangs above the floor. When needing to get up for any reason, if I’m not sufficiently careful it’s extremely easy to catch my toe in the loop of cord, and either trip or yank the power strip out of the wall. (It’s only hanging by one nail, but I figure that’s better than if it were firmly fastened which might result in the plug being damaged, as it might then pulled at a bad angle.) By contrast, with the three old computers, the cords (including adapters) always had enough play to at least partially lie on the floor, provided you sat anywhere reasonably near a power socket.

It does seem strange that the AC cords of our new computers are so much shorter than we’re used to, and this leads me to wonder: In contrast to the batteries of five or more years ago, are the batteries currently shipping with new laptops meant to be…er…actually used? As in, “that’s what the battery’s there for, so don’t be afraid to use it”, as opposed to the idea that it’s only there for emergencies? In the past I was always more comfortable using a computer on AC current, but with this new one it’s just plain awkward to do so. So should I routinely use the battery until I need to recharge it? Or should I routinely use the computer on current except if I’m out somewhere and don’t have access to a power socket?

Use your computer the way it is most convenient for you. If you are close to a socket, plug it in. If not, go DC. With older battery technology you really had to baby them, but not anymore. Keep your batteries as cool as possible (not cold) and don’t do deep discharge/recharge cycles and your batteries will outlive the useful life of your laptops.

Li-ion batteries die in a few years anyway even if you do absolutely nothing with them. They degrade with time and with use. They die a little less slowly from smaller discharges than a few big ones (i.e., it’ll last longer if you charge-cycle it 10% 100x than 100% 10x) but my readings and experience suggest that the difference isn’t great. And yeah, there are small differences in capacity decrease based on storage temperature and stored charge levels, but meh, not enough to worry about.

In practice, if you bought your laptop new, the battery will be useless in two or three years anyway no matter what you do with it. At best maybe you can extend its useful life by a few months. When that point comes, if you’re not ready for a new laptop yet, just install a new battery (or get a third party to do so) and recycle/e-waste the old one.

So use it as you want to. Keep it plugged in when there’s no reason to unplug it, but don’t be afraid to take it places and actually use it like a, well, laptop.

In addition to battery life, and depending on the laptop, you want to think about the physical durability of the AC plug. I plug in my laptop when I am sitting very still and holding it flat, but I don’t leave it plugged in while I am balancing it on my lap on the couch. I left my last (cheap) laptop plugged in all the time, and eventually the pin where you plug in the cord got bent or broken, and I couldn’t plug it in anymore. I think all the jostling and rough treatment while plugged in caused that.

I was arguing with a friend about our respective iPad batteries. My friend kept it plugged in all the time. I tried to keep mine charged when it dropped to 50 per cent.

After reading much contradictory advice on the net, I emailed Apple support in an attempt to settle the matter.

The Apple representative finally said after my asking point-blank no less than three times — it seems that Apple didn’t want to admit to anything — that leaving an iPad plugged in all the time would degrade the battery faster than otherwise. He wouldn’t say why, but I suspect that despite claims to the contrary, the battery develops a charge-range memory.

The rep said that when the iPad is being used while being plugged in all the time, it cycles between a 94-per-cent charge and 100 per cent, which is not ideal, but that none of it’s products can be overcharged, at least with an Apple charger.

He finally said that it’s best to charge the battery when it drops to the 60-per-cent range.

I have read on Apple sites that Apple ships its products with an an approximate 50-per-cent charge, which gives lithium-ion batteries the longest shelf life, and that the belief they need to be run down to near zero to calibrate them is a battery-damaging myth.

I doubt that lithium-ion batteries in non-Apple products would be any different.

We’ve had a couple of AC cords fail after at least five years of use, but it wasn’t too much of a problem as we also found replacement cords to be easy enough to get.