How to Charge Lithium-ion Battery Packs – Charging Methods, Charger Making, and Battery Concerns

Lithium-ion batteries are a powerful yet delicate battery that has protected the revolution and advancement of technology by supplying sufficient amounts of energy for decades. However, as much as these cells seem to be capable of powering a sturdy industrial future, they need to be handled carefully and especially when it comes to charging. This guide aims at taking you through the proper steps towards charging your battery the right way and how to maintain them well for their utmost performance.  

How do you charge Lithium-ion battery pack? 

Charging lithium-ion battery packs is a delicate procedure that needs to be monitored because as much as these cells are powerful, they also contain a few flaws.  

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1. Charging new battery packs 

When you get a new lithium-ion battery pack, you don't need to discharge and charge its first cycle fully. These cells have a maximum capacity that is available at the beginning and, therefore, its first charge is similar to the 10th one.  

Solution: All you need Is to top the charge to full capacity, and you're ready to start using the battery. 

2. Regular charging 

The lifespan of a regular lithium-ion battery is expected to last about 300 - 500 charge/discharge cycles, which usually translates to around 2 -3 years of service. During this period, the batteries are expected to experience reduced capacity due to degradation that occurs on all battery technologies. This natural reduction in the battery's capacity is usually associated with several factors like charge cycling, storage, changes in temperature, general aging, and the frequency of the battery's use.  

To reduce the risks of damaging your lithium-ion battery and, therefore, increase the rate of degradation, you are advised to use the original battery charger. These designated chargers that come with the battery pack have in-built circuits specially designed to maintain the right cell conditions during charging periods.  

Solution:  

Charge your battery as recommended by the manufacturer. Don't stress yourself over the issue of fully discharging your battery because partial, as well as random chargers, are good for your battery's health. For your safety and that of the lithium-ion battery, try using the designated charger that came with the pack.  

Also, when charging the cells, make sure to do so at room temperature and never charge the lithium-ion battery below 0°C or above 40°C. 

3. Charging at extreme temperatures 

Like humans, lithium-ion batteries are sensitive to temperature changes and function best when it's neither too hot nor too cold. Room temperature is the best condition for these cells. However, the batteries tend to perform better at high temperatures as compared to low ones because heat lowers the internal resistance of the cells.  

The low resistance speeds up the chemical reaction within the cells, increasing the performance of the battery. However, the side effects include too much pressure on the battery, and this leads to a shortened life span. On the other hand, cold temperatures raise the internal resistance of the cells forcing the battery to work harder while reducing the capacity. For example, a lithium-ion battery that supplies 100% of its capacity at 27°C would usually decrease by about 50% at -18°C.  

Solution: 

The temperature of the surrounding environment of the battery significantly affects the performance of the cell. To get the most out of this performance, you are advised to charge your battery at room temperature and operate/store in cool, dry temperatures.  

Can you make a lithium-ion battery pack charger? 

Yes, it's possible to construct your own lithium-ion battery pack charger if you don't have the original one. Using the right steps, you can construct an inexpensive charger that works perfectly for your lithium-ion cells.  

However, this process requires high levels of safety because, unlike the accident-proofed manufacturing industries, you would be experimenting alone. Always take safety measures by wearing goggles and rubber gloves and be sure to carry out the project in a safe environment with fire extinguishers around. If you don't know your way around the cells, have an expert near you or an adult as a supervisor. 

How do you keep your lithium-ion battery pack healthy? 

There are many guides and shout outs to battery users on how they can conserve their batteries' power, but little to do with keeping them healthy. To maintain a healthy battery, you can take the following measures when handling them. 

4. Keep the cells at room temperature. 

Room temperature lies between 20°C and 25°C. For a fully charged lithium-ion battery, elevated temperatures are one of its most critical enemies. When it comes to reducing your battery's life, heat can be your most determining factor. Therefore, try not to leave your fully charged cell in extreme temperatures like a locked car or out in the sun.  

5. Partial discharges are healthier than full ones. 

Lithium-ion batteries aren't affected by the common charge memory defect that troubled the older battery versions such as NiCad cells. For this reason, deep-discharge cycles are deemed unnecessary when handling lithium-ion batteries. Therefore, you are advised to let the battery undergo partial discharge cycles.  

However, there is only one exception to this rule. Battery experts and manufacturers recommend that once after every 0 charges, you are required to discharge the lithium-ion cells fully. If you consistently discharge your battery partially without giving it a chance to drain completely, the cells can be affected by a condition called digital memory. This effect affects the accuracy of the power gauge and requires you to recalibrate the device.  

6. For long-term storage, discharge the cells to about 40% 

Never store your battery for extended periods while it's at full capacity. Storing a fully charged lithium-ion battery for months or years on end is dangerous because the rate at which the oxidation of lithium ions takes place is very high. It would be best if you store your battery at 40% discharge and in a cool place such as the refrigerator.  

7. Avoid complete discharges 

If a lithium battery was to be discharged below the cut-off voltage of 2.5V per cell, an in-built safety circuit opens up, and the battery may seem dead. You wouldn't be capable of charging the cells using the original charger anymore. Also, try not to recharge deeply discharged lithium-ion batteries if they had been stored in that condition for extended periods.  

Takeaway 

Lithium-ion batteries are, by far, the best and most powerful battery technology in the market, offering a wide range of improved versions like the LiPo cells. Maximizing the battery's performance and getting the most out of its full lifespan is possible for any battery user provided they follow the above guidelines.