Is it ok to leave the Lithium-ion battery on the charger?

Is it ok to leave the Lithium-ion battery on the charger? Lithium-ion or Li-ion batteries use lithium as a negative electrode and non-aqueous solutions as electrolytes.

They are becoming very popular in the automotive industry due to their high performance and low danger.

Moreover they are low maintenance and can effectively power your vehicle for an extended lifetime.

To charge the Lithium-ion battery, you will need to use special charges that can maintain its health as well.

But sometimes, we tend to forget the battery with the charger. Is it okay in the Li-ion battery case, or must you be vigilant?

Let’s look into the details related to it.

What is a Charging Cycle of Li-ion Batteries?

A rechargeable battery’s charging cycle is when it charges and then discharges. The charging cycle starts when you plug into the charger and ends on the next charge. 

Also, as you use the battery for work, you use the power stored during charging and discharge.

You have to look into the charge cycles it can tolerate before its performance decreases. That is as important as the battery life (milliamps hours or mAh) and voltage metrics. 

Also, the charge cycle could be a proper charge-to-discharge time or a small interval where you put the charging just to maintain the battery.

What are deep and shallow charging of Li-ion Batteries?

Lithium batteries have a charge cycle range of 300-500 on average. If you use half of the capacity, you can even charge it 600 to 1000 times before its health deteriorates.

So the number of charges is unpredictable, but you charge the battery, the total power is always 300Q-500Q.

If a full discharge gives Q capacity, the battery will deliver 300Q-500Q power over its life.

You can see the lifespan is proportional to the overall charge of the battery, not the number of charges.

Deep and shallow charging for such batteries has similar benefits over their lifespan.

Shallow charging provides short bursts of energy to the system but makes the battery unable for extended periods.

However, with deep charging, you manage the battery for long-term usage by reaching it much below 50% discharge before recharging.

So install a discharge control unit over the battery to turn it off as it reaches below 50% charging. 

How can you get cycles out of a Lithium Ion battery?

Inside of Lithium-ion battery

Captions: Inside of Lithium-ion battery

The average lifespan of a lithium-ion battery is two to three years. But in reality, it can go for around 10-15 years, 3 times longer than the lead-acid batteries’ 5-7 years.

Rechargeable lithium-ion batteries slowly start to lose the capacity to retain power, and you cannot do anything about it.

The reduction will increase with time and drain the hours of powering up the system.

However, cycling can prolong the battery life. While the fully charged battery drained to 25% has a great capacity loss, the loss of the entirely depleted battery is even worse.

Charging to 100% and draining to 50% leads to worse capacity loss than charging to 85 and discharging to 25%.

Charging the battery to 75% and draining it to 65% results in the lowest capacity loss.

Is it ok to leave the Lithium-ion Battery on the Charger?

Leaving the Lithium-ion Battery on the charger requires a few parameters to be engaged. For properly charging a battery, you look into the current, voltage, and CC/CV profile.

CC/CV charging means the charger provides constant current to establish a voltage level. As it attains the level, the current stops flowing.

Thus as long as the voltage levels are within the right limit, leaving the battery with the charger is safe.

But if the current or voltage levels fluctuate, remove the charger when the lithium battery reaches full charging.

What are the effects of Battery Overcharging?

Battery Charger

Caption: Battery Charger

Normally, the lithium-ion battery will not overcharge if you leave it with the charger.

Overcharging occurs as you charge it with a higher voltage than the required one. You can control this issue using the right chargers with the appropriate AmpHour rating, type and output voltage.

After the battery reaches its peak voltage limit, it enters the saturated charge state, taking only one or two hours for the full process to complete.

You can use the Li-ion batteries until they are drained to 20% of their capacity.

However, you can plug it in between your working shifts so your machines don’t stop when working.  That will not hurt the lithium battery’s health as it will if you are using a lead-acid battery.

Additionally, many Li-ion batteries come with a built-inside charging mechanism so that you won’t need extra wires or chargers.

Just plug them into the wall socket directly and charge the battery.
If the lithium-ion battery overcharges are due to some reason, the pressure and the temperature inside increases.

But it doesn’t often happen since they have a protection circuit that stops the current as it detects such activity.

Moreover, battery packs contain a management system that helps check the status and unplugs it when the battery is fully charged.

How to keep my Lithium-Ion battery healthy?

 Tesla lithium Ion batteries

Caption: Tesla lithium Ion batteries

Your actions with the battery will affect the battery’s life and lifespan in the long run. So it is essential to know how to maintain the battery’s health.

Following are some tips you can remember while dealing with a Lithium-ion battery.

  • Use partial Discharge Cycles: Total depletion of the battery can affect the battery’s health.  So it is recommended to use shallow discharge cycles for high performance.
  • Avoid High Currents for Charging and Discharging: High currents can stress the battery, reducing its lifecycle. To avoid that, some batteries have a protective circuit that shunts the system down as the current surpasses the threshold.
  • Avoid deep discharges: Deep discharging can harm the lithium batteries irreversibly, causing internal short circuits. Low Float Voltage can help you avoid 100% charge capacity of the battery while improving the lifecycle up to 5 times than normal.
  • Limit Temperature of the battery: Any extreme temperature, whether high or low, can destroy the internal plating of the Li-ion battery.  So it’s better to monitor the temperature manually or use sensors.
  • Be Vigilant to Overcharging: Overcharging can lead to internal plate defects and short circuits.  So use a battery monitor to check the status and unplug the battery as soon as it is completely charged.
  • Avoid Extreme Moisture: High moisture environments can corrode the metallic parts of the battery. So do not use lithium-ion batteries in moist areas without protection.
  • Use appropriate Battery Chargers: In the end, using an appropriate charger will affect the battery’s health and improve it. Hence, invest in a high-quality charger with a battery monitor display and good wires to improve the charging cycle.


To use lithium-ion batteries to their full potential, you must understand the charge and discharge cycles along with other terminologies.

Also, leaving the battery plugged in won’t harm it as soon as it has a protection mechanism. But it’s better to avoid it overall.

At Cloom, we ensure that our customers get the best out of us in terms of products, information or services.