May 09, 2020 Pageview:3293
The discharge or charge cycle refers to the complete discharge of a battery charged following the recharge. However, batteries are never fully discharged. Manufacturers use an 80% formula of depth-of- discharge to rate batteries. For this reason, 80% of the energy available is delivered while 20% is reserved. Moreover, manufacturers claim that the lifespan of a battery is increased when it is cycled lower than a full discharge. Lithium technology can also result in extreme heating and internal short circuits.
Is it ok to fully discharge a lithium battery?
This is a question frequently asked by customers. It is known everywhere that lithium batteries should not be deeply discharged. Generally, a fully charged voltage of a lithium battery is around 3.65V, and 20V is for fully discharged voltage. This means that overcharging will put more energy on cells hence destroying the cell. The damage can be extreme and result from firing. For instance, copper found on anode dissolves to the electrolyte. Then the copper sticks on anode while charging and causes dendrites. Therefore, the complete discharge of lithium batteries is a dangerous process.
Most devices today use lithium batteries that have no memory effect. Try to always perform partial discharge to around 40% to 70% prior to recharging the battery. You should not allow the battery to go beyond 20%. Suppose you want to discharge the battery up to 50%, try to recharge and discharge to 50%. This counts one cycle with lithium batteries. On the contrary, you should not leave the battery at fully charged for a long period. This will reduce lifespan and loss of capacity. If you want to leave it for six months, charge to 50% before you store. Nevertheless, no need to tense if you are using it frequently.
Do not worry about doing partial charges. Shallow discharge can only result in minor problems. For example, personal computers can get confused and display the wrong percentage of how the battery charge will last. Manufacturers for laptops recommend users to do complete discharge once every month. It will assist in measuring the battery of the device according to the estimated time.
The battery management system should be incorporated so as the cells are balanced. This will also ensure that they discharge at the same levels. Another way is to make sure cells at the production line are balanced. Batteries must be assembled basing on the rate of charge cells and capacity. Also, battery builders use methods such as active, passive, top balancing, and bottom. Never leave your battery to stay at a deeply discharged state for long. Cells cannot discharge to zero, but in case they do, recharge it soon. Avoid leaving the uncharged device without charging it.
What is the fastest way to discharge a lithium battery?
Most modern lithium batteries are packed with an internal circuit. This stops them from deeply discharging that can cause the cell to damage. You can discharge them to C/10 until no current is passed. Suppose they are 5Ahr, you can discharge until 500Ma. Most battery packs have the same rate of C/10. Most notably, lithium batteries should not be disposed of when they contain power.
Resistors or LEDs can discharge batteries safely and quickly. As an illustration, to discharge eight batteries, you need a good resistor value of 100mA/12Volts=120 ohms. You need to ensure that that the resistor has a higher power rating compared to the power dispersed by 100mA. If you need a 2W resistor, add a fuse to make 200mA.
Resistors are the right option by ensuring the process is safe. Cool things prevent melting insulation and destroying batteries. It gives enough resistance that will keep the temperatures cool.
How much can you discharge a lithium battery?
It is recommended to store a lithium battery to 40% discharge. This is safe if you are going to keep it for a long period. In case it is kept while fully charged, the oxidation will be at a high rate. In addition, lithium batteries have a safety inbuilt circuit that opens up when they are discharged below 2.5volts. Do not discharge a battery beyond the instructions of the manufacturer. It will affect the original charger, and only experts will be able to boost function. Lastly, deeply discharged cells should not be recharged immediately, especially when left at that state for long.
Lithium batteries have no charging memory effect. Use partial discharges and not deep ones. Lithium experts suggest that after 30 charges, they can be discharged completely. Continuous partial discharges can cause digital memory as well as reduce the accurate performance of a device.
Guidelines for discharging a lithium battery
Never discharge lithium batteries at a higher amperage rate compared to the specific label on the battery
The battery's temperature should not go beyond 140 degrees Celsius. Cool the battery when discharging.
The battery should not be discharged below the labeled voltage. If you discharge lower than the recommended voltage, it will damage, reduce performance, and cause a fire.
Lithium batteries should not be discharged below 3V in each cell. Follow the cut off voltage.
Attend to the battery and monitor potential problems which can come on the way
Stop the process instantly in case of a problem. Put it in a safe place and assess the problem. A safe area means away from the building or cars since it can cause a chemical reaction.
Check the battery’s condition. Stop using it if the cells are not properly balanced or puffing ones. The safety of your device lies in your hands. It is your job to maintain and take care of cells so as to avoid accidents.
Final thoughts
Research of battery is focusing much on lithium technology until one imagines that the future lies on them. This means that they are superior and are a great improvement than other technologies. Most applications that were held standby by lead-acid batteries are growing after introducing li-ion. Additionally, all batteries have the aim of storing energy and releasing it at a certain time. Never leave the battery to stay at the discharge rate. Conversely, leaving a fully charged battery for a long time can cause damage. The systems have unique requirements when it comes to depth of discharge and charging speed. Follow the guidelines and get 500 discharge cycles as well as prolong lifespan.
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