How To Increase The Lifetime Of Your Laptop Battery

Battery lifetime not only depends on the type of battery and its quality, it also depends on how the battery is cared for. In this article I will explain what determines the lifetime of Lithium-Ion batteries, the type of rechargeable battery found in most if not all modern laptops, and what you can do to increase your battery lifetime.

Introduction To Lithium-Ion Batteries (Li-Ion)

Modern laptops are almost exclusively delivered with Li-Ion batteries. They are lighter, offer a higher performance, maintain their charger longer, and are less susceptible to the dreaded memory effect than previous types of rechargeable batteries.

In the US, Li-Ion batteries are classified as non-hazardous for the environment as they do not contain free toxic metals. In the EU however, vendors are required to recycle at least 25% of the batteries they produce. After all, Li-Ion batteries do contain material worth recycling, although the cost of doing so is rather high.

Priming Li-Ion Batteries

The predominant statement you will find is that new Li-Ion batteries do not require priming. Nevertheless, you should fully charge your Li-Ion battery before using it for the first time.

Cycling Li-Ion Batteries

Li-Ion batteries have a lifetime of 300 to 500 full charging cycles or up to 2000 partial cycles. There are reports that cycling a Li-Ion battery after long storage periods, i.e. fully discharging and re-charging it for two or three cycles, leads to to capacity gains. Other sources recommend cycling Li-Ion batteries every couple of weeks. Generally, you should not fully discharge your Li-Ion battery.

Caring For Your Li-Ion Battery

While Li-Ion batteries do not have a memory effect and don’t need to be primed or cycled to maintain full capacity, their lifetime can still be shortened dramatically, if not cared for right. Two things can damage Li-Ion batteries: deep discharges and heat. All of the following battery DOs and DON’Ts are derived from these two major factors.

Li-Ion Battery DOs

• partially discharge and recharge (no memory effect).
• charge at lower voltage.
• take out battery when laptop is running with AC power connected.
• store battery in refrigerator with a 40-50% charge.
• cycle the battery every few weeks or after every 30 partial charges.

Li-Ion Battery DON’Ts

• deep discharge battery.
• trickle charge.
• ultra-fast charge.
• leave fully charged battery in laptop while running on AC power (heat damage).
• freeze battery.
• buy old Li-Ion or spare batteries (Li-Ion batteries age, see below).

Aging Of Li-Ion Batteries

One more thing to keep in mind is that Li-Ion batteries begin aging the moment they are produced and there is little you can do to prevent this. What causes the aging is that the electrolyte slowly breaks down the positive plate, causing the internal resistance to increase to a point where no energy can be delivered. A partial charge and low temperatures slow down this process and hence increase the lifetime of your battery.

Summary

Li-Ion batteries are superior to Nickel-Cadmium or Nickel-Metal Hybrid batteries in that they deliver a higher performance, show a much slower self-discharge, and don’t have a memory effect. However, they do age, withstand only a limited amount of charge and discharge cycles, and are damaged by heat. The best thing you can do to preserve battery lifetime, is to store your laptop battery in a cold place whenever you have reliable AC power available. Alternatively, maintain optimal cooling and airflow to decrease heat buildup. In any case you should perform a full discharge and recharge cycle every few weeks and avoid fully discharing your Li-Ion battery in the meantime.

Sources:

• Wikipedia: Lithium-ion battery
• Lithium ion batteries: High-tech’s latest mountain of waste
• How to Prime Batteries
• Getting the most of your batteries
• How to Store Batteries
• What Causes Lithium-ion to Age?
• Lithium-ion Battery Life and Death