What Will Happen if Phone Batteries Are Overcharged?

It happened again-- mid-way through a video chat with your mom, your phone shuts down. Even though you are confident you charged it before the call, it can't seem to hold a charge lately.

This is starting to become a problem, as you depend on your phone for work and personal communications. You want to be able to rely on your investment without worrying how long you're going to be away from a power source.

You've heard about the potential to overcharge phone batteries, but now it seems all too real. Is this just a myth or the source of your recent problems?

Read on to find out.

How Batteries Charge

Most smartphones today contain a lithium-ion battery. This type of battery is different from its predecessors because of its long life expectancy, high efficiency, and lower environmental impact. It also charges faster than other types of rechargeable batteries.

When a lithium-ion battery is charging, it relies on four primary components:

• Cathode - creates the lithium ions and determines the voltage and capacity of the entire battery
• Anode - stores and releases lithium ions created in the cathode
• Electrolyte - helps move the ions
• Separator - necessary barrier between cathode and anode

When you plug a phone in, there is an activity from the positively charged ions from the anode to the cathode. When this happens, the cathode becomes positively charged-- more so than the anode. A positively charged cathode attracts negatively charged electrons.

The separator is the catalyst that promotes this movement. When a device is plugged in to charge, this sequence of events begins-- thus recharging the battery.

Learn more about how lithium-ion batteries work on the Battery University site.

What Is Overcharging?

A lithium-ion battery should have at least 400 successful charges before you start to see changes in performance. Once it hits this amount (or sooner), the battery begins to lose the capacity for a charge. We then overcompensate by charging our phones overnight, even though it only takes a lithium-ion battery a few hours to fully charge.

You might have heard about "overcharging" as a detriment to battery health. In reality, overcharging is not possible with lithium-ion batteries in our phones, as special software kicks in to stop pulling energy from the charge current once the battery hits 100%.

A real case of overcharging would actually cause the battery to swell or burn due to the amount of heat created during the charge.

Although this is true, it's the overnight (or all-day) "trickle" charging that impacts the longevity of your battery level. As your phone charges idly on the counter, it's losing a tiny amount of charge as it runs background tasks. When the protection chips detect that the battery is less than 100% charged, it compensates for the amount of energy lost.

Consistently charging batteries like this will lead to irreversible damage. This is something you may want to avoid, as replacing a device that's been damaged by a swelling or leaking battery is not the sort of thing you want to spend your spare change on.

Other Enemies of Battery Life

Trickle charging is not the only bad behavior responsible for declining battery lifespan. Keeping the following factors in mind, as well as using your phone for most of a charge, will keep you from replacing that $1,000 device sooner than you might want to.

Parasitic Load

Parasitic load happens when you leave a battery plugged in to charge but simultaneously use the device at a rate that leaves the battery drained.

Watching television, playing games, or editing photos while your phone charges can cause future problems as this behavior induces "mini charge cycles." A mini-cycle involves one small portion of the battery that is draining and charging quicker than the rest of the battery.

A parasitic load is even worse on the battery if the battery is already fully charged. Plugging your phone in to "keep it at 100%" is actually causing voltage stress and more heat.

How do you avoid parasitic load? Turn off your phone when charging, and wait to watch that new episode until you unplug the device from its power source.

Heat and Temperature Stress

Heat is the ultimate enemy to a battery. High temperatures put a lot of stress on the tiny machine--one that is responsible for a very careful chemical reaction.

Batteries are not designed to withstand high amounts of heat and may leak or explode. A battery under this amount of stress may also damage any device it is connected to.

Increases in battery temperature are directly correlated to their capacity. If a battery is kept to 77 – 86 degrees Fahrenheit (a pretty ideal temperature for a battery), it will retain about 80% of its charging capacity after one year of cycles. Pushing this temperature will rapidly expedite the process at which it can no longer hold an effective charge.

To avoid this level of heat stress, keep your phone on its own charging table. Do not allow it to charge under your pillow or blankets, and avoid charging where it will be hit by direct sunlight.

Additionally, you'll want to use fast-charging devices with caution. These high-voltage devices can create a lot of heat, which is why you'll want to avoid leaving your phone plugged into this kind of tool for an extended period of time.

Idle Charging

Leaving your phone plugged in all day may seem like one way to avoid a spent battery. However, metallic lithium plating can begin to form around the anode when the lithium ions are accumulating in the anode. This deposition will build up in the battery and cause the battery to eventually malfunction.

Additionally, a fully charged battery will generate heat as the energy doesn't have anywhere to go. Keep your home (and your phone) safe from the fallout and unplug your device as soon as it hits a full charge (or slightly less!).

Recalibrate Your Device

If you are noticing that your phone dies pretty quickly after it reaches a 30% charge, you may need to recalibrate the software that is used to detect this charge percentage. An accurate reading can be achieved by allowing the battery to drain to 0% and then charging (while off) back up to hit 100% battery.

Once it's fully charged, you can turn on your phone to see an updated reading.

Detecting Poor Battery Health

Batteries in poor health will perform with severely degraded performance. Additionally, they might give off the following warning signs of possible danger:

• The acidic smell of sulfur compounds
• Swelling of the battery unit
• Hot to touch
• Smoking device
• Electrical burn smell

If any of these warning signs are detected, the battery will need to be disposed of safely and quickly. An acid spray may be released if the battery cracks or swells enough due to the chemical reaction. This acid is very dangerous to your skin and eyes and can ruin your clothing and other household items.

How to Effectively Charge Your Phone Batteries

Do you have your heart set on keeping your current smartphone for as long as possible? Extend your battery lifespan and consider these phone charging suggestions:

• Stop overnight charging that encourages trickle overcompensation, or charging for long periods of time
• Try not to full-cycle charge (completely dead battery to 100%)
• Top off your phone more often
• End your charge at 80% battery capacity
• Use fast-charging cables responsibly-- never overnight
• Keep your phone out of hot places-- including hot vehicles, in direct sunlight, in your pocket
• Turn off your phone before charging to avoid trickle-charging
• Avoid mini-cycles by abstaining from videos and games while the device charges

If you can charge your phone for short periods of time during the day, this is the ideal method. If you can only charge overnight, stay away from fast charging tools. You don't need them!

Keep Your Phone Charged Anywhere

Keeping your phone free of cosmetic screen cracks or water damage is just one part of being a responsible phone owner. The overall longevity of your device is reliant on the health of your battery. Remaining conscious of your phone's temperature, charging tendencies, and parasitic load will keep you from having to replace the battery (or the entire device) sooner than you'd like to.

Short, consistent charging cycles and cooler temperatures will create the healthiest environment for your device.

Even if you pay attention to best charging practices, your phone batteries will eventually need some power. To prepare for a long trip or a long day void of outlets, browse our portable power banks. With a fast-charging solar power bank, you won't have to worry about losing touch again!