Do lithium batteries expire?

The life of a battery largely depends on its use, the level of maintenance the battery gets and the charging as well as the temperature and some other factors. The type of battery also determines the lifespan of the battery.

For instance, when a 12-volt gel battery or AGM remains in a charged state when not in use, its average life is six years. After five or six years of normal maintenance voltage at an average ambient temperature of 25°C, the battery will still be boasting about 80% of its original capacity. Using a battery at a higher average temperature will reduce the life of the battery.

Also, the number of charging and discharging cycles of a 12-volt battery is largely connected to the structure and quality of the battery. The Mastervolt 12-volt gel batteries take about 500 full cycles of fully discharging to 20% and recharge to full capacity.

Most battery manufacturers believe that batteries with a remaining capacity of 80% are already used up. However, this does not mean that the battery needs to be replaced immediately. The battery can still be used if for example only 50% of the battery capacity is needed. Therefore, it is not necessary that the battery is replaced after six years or 500 complete cycles. An average of seven years is normal for the 12-volt gel or AGM batteries.

What is the average life of a lithium battery?

The average lifespan of a lithium battery depends on a host of factors that can cause parasitic reactions and adversely affect the life cycle of the battery cells. Of them all, the most important are;

• Temperature

• Charge/Disconnect cut-off Voltage

• Charge/discharge current

The cells are differently rated for charging and discharging. For the discharge temperature, you may go as low as -20°C, but at this temperature, degradation will increase rapidly. Keep the temperature above 10 degrees but below 60 degrees. For the charging temperature, the temperature must be greater than 0 degrees, otherwise, a lithium plating is very likely to occur. The closer it is to 25 degrees, the better for the battery.

As for current, the lower it is, the better for the battery.

As for voltage, partially cyclic voltage, of about 3.3 V - 3.8 V, will be of significant importance to

the battery life, because the lifespan will increase significantly, at that volt instead of at a full cycle of from 2.5 V to 4.2 V.

In most cases, it is common for a 18650 lithium-ion battery to reach about 500 cycles before it uses up about 80% of its capacity (which is the international standard for the evaluation of cycle life).

However, in non-ideal conditions, it is possible that you only get 200 cycles or less. However, If you adhere to the guidelines, you are very likely to exceed the 500 cycle mark. The Lifepo4 cell can reach 1500 cycles before it uses up the 80% mark of its nominal capacity. For more information on cycling, consult your battery manufacturer's spec sheet for any battery you purchase.

Is it OK to use expired lithium batteries?

It is fascinating when we hear people ask if batteries expire.

Yes, it is true that every good thing must have an end. To find the “best before” date of a battery, you may look at the top of the battery, near the area where the battery type (AA, 9 V, etc.) is inscribed. The best user experience and battery performance are achieved when the battery is used before the best use date. The battery can work after this date, but its performance is somehow reduced. So if you are wondering if an expired battery will work, here is your answer; you can use an expired battery, but the performance will not be the same as a battery that is not expired.

What does the expiry date on the battery mean?

A battery is a chemical that generates electricity through chemical reactions. If the battery has exceeded the recommended service life or usage period, its component parts will start to deteriorate even faster than it was, which will reduce performance. For this reason, an expiration date is indicated on the battery. This is the date until manufacturers can guarantee the quality of their product.

People should know that there is a difference between the expiry dates on food items or drugs and the expiry date on batteries. Expired in both contexts means different things. For food, when the expiry date is reached, you may not eat the food because doing so will result in eating toxic food, which may be harmful to one’s health. But for a battery, when the expiry date is reached, the battery doesn’t stop working, but the performance of the battery can no longer be guaranteed by the manufacturer. The expiry date specifically tells when the battery’s total self-discharge will reach or exceed 20%.

• (Note that it is possible to use an expired battery, but this will affect the performance of the battery and there is no warranty from the manufacturer for the expected operation.)

Can a dead lithium battery be recharged?

Yes, such a battery can be recharged, but there is no manufacturer guarantee that the battery will work as well as it used to. To recharge it, follow the following steps.

• Read the voltage of the battery

Turn off the device in which the battery is being used and remove the battery. Take the reading of the voltage with a voltmeter. Lithium-ion batteries can go into sleep mode if the battery is drained too much.

• For example, if the battery has a nominal voltage of 3.7 volts and the voltmeter shows about 1.5 volts, the battery may be in sleep mode.

• Connect an appropriate charger

• Check the battery after one minute

(After one minute of ‘waking up’ the battery, check it to see how things are going, or you may consult your charger manual to know when the process will be complete.)

• Charge and unload the battery

(Return the battery into your li-ion charger and charge the battery till it’s full. Depending on the type of lithium-ion battery to be serviced, it may take about 3 hours.)

• Freeze the battery for about 24 hours (ensuring there is no moisture)

Charge the battery completely (hopefully, it’s performance will improve)