22 Years' Battery Customization
Dec 24, 2021 Pageview：1846
18650 batteries are rechargeable lithium-ion batteries that are commonly referred to as 18650 cells. These batteries have a standard nominal voltage of 3.7v and between 1800mAh and 3500mAh.
You may also get 18650 cells that have a voltage range between 2.5 volts to 4.2 volts. There are two types of the 1850 cells, namely: protected cells and unprotected cells. The 18650 protected cells have an electronic protection circuit embedded in the cell packaging that prevents the cell from overcharging. On the other hand, unprotected 18650 cells lack an electronic protection circuit and hence can burst or cause fire when overcharged.
In the article below, we discuss everything you need to know about 18650 batteries. Lets look at reasons as to why your 18650 battery is not fully charging and how to know whether your battery is bad. Let’s get started.
18650 Battery Not Charging Fully
An average 18650 battery takes about 4 hours to fully charge. Note, this time may vary based on the amperage and voltage of the charger you are using and the battery type you have. It is crucial to always know that lithium-ion batteries always need a designated voltage for them to operate safely. Therefore, your 18650 batteries will need a dedicated and recommended charger to charge them safely
Sometimes, you may find that your 18650 battery is not charging fully. It may be due to several reasons. Most times, the battery will fail to charge fully when the voltage is below a certain recommended low limit. Such a battery will need a charger with the boost feature to boost the voltage as the normal battery charger will not work. Therefore, it is important to make sure your 18650 battery is never discharged too low. To ensure your battery is fully charged, there are some basic rules you can follow when charging your 18650 batteries. these include;
Ensure you keep the voltage up to 4.2V per cell.
Always make sure the cells do not discharge below 3 volts or reach the deep discharge level.
Keep checking the charge and discharge temperatures
When charging, keep the limit to 0.5 C or follow the specified charge current.
Consider your battery’s charge cycle and capacity.
Keep monitoring the cell voltage frequently to keep the cells balanced.
However, it should be noted that the 18650 batteries, just like other lithium-ion batteries, need not be fully charged. It is better not to charge them to 100% as a high voltage will stress the battery. Shallow discharges and recharges may be the best method when you are considering prolonging the life of your battery.
Why is my 18650 Battery not charging?
A fully charged 18650 cell will be around 4.2 volts, while a discharged cell will be at 3.0 volts. It applies to all lithium-ion batteries. A deeply discharged lithium-ion battery will fall below 2.5 volts. Such a battery may be hard to revive as most lithium-ion battery chargers cannot revive battery cells that are deeply discharged.
For instance, your 18650 batteries may not be charging as it is at the low voltage cut-off threshold of 2.5 volts. It means your battery will go into sleep mode as the protection circuit will shut down all its internal operations. Most times, your battery will be practically useless unless it is boosted with enough voltage above the low voltage cut-off threshold. Only then will the protection circuit kick in, and the recharged cycle will begin. One way to boost the voltage of your battery is by having a charger that has the boost feature. Such chargers are well equipped to charge deeply discharged batteries. Once you use such chargers, you can boost the battery’s voltage and reactivate the charging circuit that was in sleep mode. However, it is recommended not to use the boost chargers when a battery’s voltage is below 1.5V for a longer duration. Attempting to charge such a battery is risky. You may end up short-circuiting the battery due to the copper shunts that have formed within the cells.
Your battery may also fail to charge due to triggered thermal protection within the battery or chemical reactions. A battery with zero voltage will point towards a thermal trip occurrence where the overheating trip has been activated. Such a condition occurs when the internal membrane of the protection circuit is in contact with the battery surface, causing the internal pressure to increase. To solve this issue, you will need to fix the battery membrane for the battery to accept a charge.
How do I know if my 18650 is bad?
The only way to know whether your 18650 battery is bad or not is by conducting a check. Apart from this, there are common signs that your battery will present when it is bad or even nearing its end of life. Some of the signs to look out for include.
Your battery will lose its charge on the shelf much faster than is normal. It may happen within a couple of days or even overnight.
It takes you abnormally long to recharge your battery.
Your battery will feel warmer to the touch when charging or discharging it.
Your battery seems to have deformation or cracking.
You have had your battery and used it frequently for over three years.
Your battery tends to hold less than 80% of its original capacity.
In case you notice your battery presenting the above signs, it may be time to get a replacement to avoid any accidents occurring while recharging. Let’s now look at steps you can take to check whether your battery is bad or not.
1.Use a voltmeter or multimeter to measure the terminal voltage of your battery.
2.In case of a minimum voltage left within the battery, connect it to a parallel connection with another battery that has the same specifications and ratings and is charging properly.
3.The connection will boost a positive change in the terminal velocity of the battery, making the battery charge.
4.Sometimes the terminal voltage will remain zero even after multiple attempts to charge the battery. It will mean the 18650-cell charge is deeply discharged.
Note
It is highly recommended not to recharge or use your battery without knowing its voltage. Only boost your battery when you are sure it has dropped down to the terminal voltage.
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