Numerous portable electrical and electronic devices, including watches, smartphones, laptops, remote control devices, and much more, are powered by batteries.

There are many different types of batteries in use today, each with their own special qualities.

Lithium-Ion batteries are among the most widely used today.

The lithium-ion battery will eventually run out of juice (lose all of its charge), and if it’s a rechargeable battery, it will need to be recharged.

Knowing the voltage at which a lithium-ion battery completely loses its charge will help you prolong the battery’s life because it is not ideal to let a battery run completely flat.

What voltage then qualifies as a Lithium-Ion battery’s “dead” state? Around 3.4 volts is the voltage at which a lithium-ion battery dies.

This voltage can change depending on the manufacturer, the temperature, and other elements.

When they are dead, lithium-ion batteries shouldn’t be used.

They have a cutoff circuit that prevents them from being used after they have lost all of their charge.

The discharge profile of lithium-ion batteries will be examined in more detail in this article.

Closer Inspection Of A Lithium-Ion Battery

There are numerous batteries in use today, and while they all serve the same basic purpose—supplying energy to electrical and electronic devices—they are all unique in a variety of other ways.

The following traits:

  • Chemical structure
  • Normative voltage
  • present capability
  • Shape
  • Size
  • Density of Energy
  • Particular Energy density

The Chemical Composition is the primary feature that significantly influences many of the other parameters (such as voltage, current capacity, energy density, etc.).

Batteries provide electrical power via internal chemical processes.

Several different compounds, including the following, are used in various batteries.

  • Nickel-Cadmium (Ni-Cd)
  • Zinc-Carbon
  • Lithium-Ion (Li-Ion)
  • Lead-Acid
  • Alkaline

Lithium-Ion is the chemical component of this article with which we are primarily concerned (Li-On).

Lithium ions flow from the negative electrode via an electrolyte and towards the positive electrode in the cells that make up the battery.

Voltage Of A Lithium-Ion Battery When New

Understanding the voltage at which a lithium-ion battery is operational will first aid in determining the voltage at which the battery is dead.

When choosing a battery for a given application, one of the most crucial features is the battery’s voltage.

Every electrical and electronic gadget needs a certain voltage rating in order to function properly and effectively.

To meet the demands of the gadget, you must choose a battery with the correct voltage (or a little higher).

The voltage of a battery is expressed in the common international unit of voltage and describes the amount of electrical potential it can store (V).

There is a theoretical voltage for every battery, but the nominal voltage generated is the actual voltage.

The amount of current taken by the load and the internal impedance of the battery are the main determinants of this, which is caused by polarization and resistance losses.

A lithium-ion battery can produce a maximum voltage of 4.2V, but this will quickly decrease to its normal value of 3.7V.

Various Lithium-Ion Battery Types

Power tools and RC aircraft are just a few of the numerous applications that may benefit from using lithium-ion batteries, which are available in a number of sizes and configurations.

The various shapes for lithium-ion batteries are listed below:

  • Little cylinder (single cell with, solid body, with no terminals)
  • Enormous cylindrical (single cell,solid body, with threaded terminals)
  • Flat or satchel (soft, flat body)
  • Solid plastic container (large threaded terminals)

But do the various lithium-ion battery shapes all have the same voltage?

Yes, the batteries have the same nominal voltage of 3.7V even though their sizes differ.

What about electronics that use lithium-ion batteries and call for higher voltages? Lithium-ion batteries can be connected in series to produce a higher voltage.

Due to the need to match the impedances of lithium-ion batteries, this process is a little trickier than simply connecting other batteries in series.

With their impedances matched, of course, two lithium-ion batteries linked in series will now have a nominal voltage of 7.4V.

The voltage will consequently rise by 3.7V when more batteries are added.

With these higher voltages, packs of lithium-ion batteries are readily available.

What Voltage A Lithium-Ion Battery Dies?

When using a lithium-ion battery, we need to be aware of a few different voltages (or any other battery for that matter).

The first is the nominal voltage for lithium-ion batteries, which is currently understood to be 3.7V.

The voltage at which the battery is said to be dead, or when it has completely lost its charge, is another voltage of the highest significance.

Knowing this voltage is crucial because the battery must be recharged to its nominal voltage before it can power electronics efficiently.

So, at what voltage is a lithium-ion battery deemed to be dead?

Around 3.4V is the voltage at which a lithium-ion battery is no longer functional.

A cutoff circuitry kicks in about 3V and disconnects the battery for safety if the battery is still connected and continues to deplete after 3.4V.

What May Impact How Quickly A Lithium-Ion Battery Dies?

The lithium-ion battery’s rate of discharge may be influenced by a number of variables, the two main ones being;

  • Load
  • Temperature


The load put on the battery is the first apparent element.

Imagine wearing a backpack to symbolize the burden, and your energy levels to represent the batteries.

This is a perfect comparison.

The weight of the backpack will increase if it contains several objects.

You must thus use more energy to bear the burden, which will make you weary more quickly (lose all your energy).

However, you would need to exert less strength to carry the bag if it was empty or contained just a small number of objects (which would reduce its weight significantly).

This implies that you could go further.

Batteries work on a similar principle.

The battery will have to produce more energy if a heavier load is put on it (such as operating a motor), which will cause it to lose charge more quickly and eventually run out of power.

The battery will last a lot longer if it is attached to something like an LED, which uses a lot less power than a motor.


Temperature is the next significant aspect that affects a battery’s performance.

There are a number of optimal temperatures for charging and discharging lithium-ion batteries.

Lithium-ion batteries work best when charged between 32°F (0°C) and 113°F (45°C), and when discharged between -4°F (-20°C) and 140°F (60°C).

However, it is not advised to use lithium-ion batteries in very hot or cold environments to charge or discharge them (either real cold or hot).

Greater performance and improved storage capacity may be transient benefits of higher temperatures, but a shorter life cycle is a long-term adverse effect.

Every battery has an internal resistance, and this resistance rises when the battery is exposed to much lower temperatures.

As a result, the battery loses power and depletes more quickly since it must exert more effort to overcome the rise in resistance.

What Happens When A Lithium-Ion Battery Runs Out Of Power

When it comes to voltage, there are two things to avoid doing with a lithium-ion battery:

  • Never charge them beyond the 4.2V maximum safe voltage.
  • Keep them over the 3V minimum safe voltage while discharging them.

Fortunately for you and me, we don’t need to continually check the battery to determine whether the voltage exceeds these two thresholds.

Lithium-ion batteries need a particular charger while being charged to make sure the maximum voltage is not exceeded.

This implies that trickle charging is absent from lithium-ion battery chargers (which is a common technique used to charge a battery when it has reached full charge).

The battery charger stops charging the lithium-ion battery after it has fully charged.

Lithium-ion batteries have a similar protective circuit integrated into the cell for discharge (usually at the the top of the battery covered in tape).

When the battery is dead, this protective circuit will keep track of it and disconnect it to prevent harm.

If A Lithium-Ion Battery Is Not Used, May It Die?

Yes, if a lithium-ion battery is not utilized, it may die (even though it is not supplying a load).

All batteries have what is referred to as a shelf life.

A battery’s shelf life indicates how long it can maintain its charge while not in use.

The battery will then begin to lose energy and need recharging (if it is a rechargeable battery).

At room temperature, lithium-ion batteries self-discharge at a rate of 5% every month.

If the battery is not used for more than a year, irreversible capacity loss happens.

Never attempt to recharge a battery if the voltage is 1.5V or below.

An accumulation of copper shunts within the battery over an extended length of time may result in shorts, excessive heating, and, in the worst case scenario, an explosion.

Identifying A Dead Lithium-Ion Battery: A Test

Using a multimeter to check a lithium-ion battery’s voltage to determine if it is dead is the simplest method.

A multimeter is a kind of electronic measuring device that can do a variety of tasks, such as measuring voltage, current, resistance, continuity, frequency, diode testing, etc.

The complexity of the multimeter is the only factor affecting how many electrical values it can measure.

However, all common multimeters will measure voltage, current, and resistance—the three key metrics.

The methods listed below should be used to gauge a lithium-ion battery’s voltage:

  1. Set the voltage mode on the multimeter (ensure the voltage of the battery you are measuring is within the range of the multimeters capability)
  2. Connect the multimeter’s positive (red) lead to the battery’s positive terminal.
  3. Connect the multimeter’s negative (black) lead to the battery’s negative terminal.
  4. Keep an eye on the voltage that the multimeter shows.

When a lithium-ion battery is almost dead, should you still use it?

Should you keep using a lithium-ion if you check its voltage and it’s getting close to its dead voltage of 3.4V?

No, recharging the battery is the best course of action here.

A battery’s lifetime may be significantly shortened if it is used while it is almost dead.

At What Voltage Is A Lithium-Ion Battery Dead? Videos Suggestions From Youtube

DIY: How to revive a dead 18650 (or any) Li-ion battery cell – vuaeco
Back from the DEAD! Lithium Batteries! – Real Tool Reviews
DIY: How to Revive a dead Li-ion power tool battery – vuaeco

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Written by Bob Matsuoka
Bob Matsuoka is a blogger and founder of RVing Beginner blog. He has been blogging for over five years, writing about his own family’s RV adventures, tips for people who are interested in buying an RV or taking their family on an adventure by RV.