Question on Increasing Longevity of Laptop Batteries

Question

Is it possible to make my laptop charger only charge when the battery is almost dead? Then, once it is fully charged to not activate charging again until it becomes close to dead again?

Would that require an adapter of some sort?

Answer 1

What you're asking for (how to prevent the battery from being recharged before it's empty) is not the best way to achieve what you want (avoid wearing out the battery).

1. Discharging to 5% is not good for the battery, you want the minimal state of charge to be higher than that.
2. A battery has a limited number of charge/discharge cycles available (usually 1000 cycles). Partial charge cycles are counted as partial cycles: you can either do a full discharge/charge cycle 1000 times, or charge the battery from 50% to 60% 10,0000 times. That means it's not necessary to do full discharge/charge cycles.

The charging circuit inside the laptop will do some things to protect the battery: when your battery is fully charged, the charging circuit inside the laptop will stop charging the battery. The laptop is powered by the mains directly, and the battery is mostly inactive. Apple laptops will start charging again when the battery drops below 95%.

You could increase battery life a bit by always keeping the state of charge between ~30% and 70%. I haven't seen programs that will manage this for you though.

To avoid wearing out the battery: keep the laptop plugged in as much as possible. Install a battery monitoring application like CoconutBattery (for Mac), which will tell you to run on battery for about 20 minutes/day (so the battery gets some use), and keep the laptop plugged in otherwise.

Reference

Answer 2

You can impose your will on your laptop battery drain and charge limits using the power management utility found in your system preferences. Usually, this is set to optimize the balance between system performance and power requirements. You can ignore the recommendations to adapt your system to your requirements and limitations.

If the operating system does not find the level you desire, you could probably use a command-line request for your wish. You will do so not knowing what other settings will be affected by your change. Run your idea by your system/battery technical support for their best practices and suggestions.

Good luck.

Answer 3

This answer addresses general issue in the title — Increasing Longevity of Laptop Batteries — as opposed to the more specific details regarding control of battery recharge frequency requested in the body of the question.

Tips to Increase Rechargeable Battery Life and Lifespan
“Battery life” is the amount of time your device runs before it needs to be recharged. “Battery lifespan” is the amount of time your battery lasts until it needs to be replaced.

Maximize both and you’ll get the most out of your devices, no matter which ones you own.

If you own almost any rechargeable device, it probably runs on a lithium ion battery. They pack a ton of power into a small space and do a great job of holding on to that power when not in use. The capacity of all lithium ion batteries declines over time, regardless. It’s perfectly normal and unavoidable.

When maintained properly, a battery can keep 80 percent of its original capacity after 400 full charge-and-discharge cycles.

But without proper care, your battery won’t keep its charge as well as it used to or as well as it could.

Best Practices Here are things you can do optimize the overall performance of a rechargeable battery…

1. Stop running it down First, stop running it all the way down. In fact, try not to drop below 20 percent. Think of your battery like a muscle. Working out at a gym for 20 minutes a day will get you into shape, but doing it for 20 hours a day until you're exhausted isn’t something you can keep up for very long.

2. Use it or lose it But you also shouldn’t leave your battery fully charged all the time. Using the muscle analogy, your battery will atrophy if you never exercise it. So unplug it from the charger every once-in-a-while and try to run it down by at least 10 percent.

Some manufacturers may also recommend that you fully charge your battery, then completely drain it once a month. This is typically done to recalibrate the device’s internal counter, which is used when estimating how much power you have left. But don’t do it more often than necessary as this doesn't add capacity.

3. Don't blow your cool. Your device is designed to perform well in a wide range of ambient temperatures, with 62°– 72° F (16°– 22° C) as the Goldilocks zone. It’s especially important to avoid exposing your device to ambient temperatures higher than 95° F (35° C), which can permanently damage battery capacity. Even leaving a battery in a hot environment—like in the sun or a hot car—can damage it irreversibly. That is, your battery won’t power your device as long on a given charge. Charging the device in high ambient temperatures can damage it further. Power Management software may limit charging above 80% when the recommended battery temperatures are exceeded.

Charging batteries inside certain styles of cases may generate excess heat which can affect battery capacity. If you notice that your device gets hot when you charge it, keep it as well ventilated as possible—good advice to follow as a rule.

Heat is the natural enemy of lithium ion batteries. Even at room temperature, one year of use can permanently reduce your battery’s capacity by as much as 20 percent – and something like a laptop will run much warmer than room temperature. If you’re going to put a laptop through an extended period of heavy use, a good suggestion is to plug it in and remove the battery, storing it separately from your laptop in a cooler location. Whether your battery can be removed or not, You may want to invest in a cooling pad. It’ll put an extra fan or two underneath your laptop to suck excess heat way.

When using your device in a very cold environment, you may notice a decrease in battery life, but this condition is only temporary. Once the battery’s temperature returns to its normal operating range, its performance will return to normal as well.

4. Long-term storage—removable battery If you’ve got an extra battery that you rarely use, or have decided to run your laptop off its charger and store your battery somewhere else until needed, many manufacturers recommend keeping it in a refrigerator with a 50-percent charge.

The refrigerator is a nice, cool place – ideal for long-term battery storage. But don’t put it in the freezer. Anything below freezing is too cold and will hasten your battery’s demise.

Two key factors will affect the overall health of your battery: the environmental temperature and the percentage of charge on the battery when it’s powered down for storage.

If you plan to store your device for longer than six months, charge it to 50% every six months.

Depending on how long you store your device, it may be in a low-battery state when you remove it from long-term storage. After it’s removed from storage, it may require 20 minutes of charging with the original adapter before you can use it.

Good luck.