Tuesday, May 24, 2011

Charging Lithium-ion Batteries Especially 18650

There is only one method to charge lithium-based batteries. The self-styled “miracle chargers”, which promise to reinstate and prolong batteries, do not exist for lithium chemistries. Neither does fantastic-fast charging apply.
Makers of lithium-ion cells have very stringent guiding principles in charge processes and the pack should be charged as per the producers “typical” charge method.
Lithium-ion is a very clean structure and does not require priming as nickel-based batteries do. The 1st charge is no dissimilar to the 5th or the 50th charge. Labels teaching to charge the battery for 8 hours or more for the initial time may be a leftover from the nickel battery days.
Most batteries are charged to 4.20 volts by a tolerance of +/?0.05V/cell. Charging merely to 4.10V abridged the capacity by 10% but gives a longer service life. Newer cell are able to deliver a superior cycle count with a charge to 4.20 volts a cell.
Even though the voltage peak is attained faster with elevated current, the topping charge will take much time. The charge time of the majority chargers is nearly 3 hours. Little batteries utilized for cell phones can be charged at 1C; the larger 18650 cell/battery used for laptops should be charged at 0.8C or a smaller amount than that. The charge competence is 99.9% and the battery remains chilly throughout the charging. Full charge is achieved after the voltage threshold has been attained and the current has fallen to 3% of the rated current or has leveled off.

Some chargers, such as 18650 chargers, claim to fast-charge a lithium-ion battery in an hour or less. Such a charger removes stage 2 and goes straight to “ready” once the voltage threshold attained the end of stage 1. The charge intensity at this point is nearly 70%. The topping charge normally takes two times as long as the first charge.

No trickle charge is used for the reason that lithium-ion is not capable to absorb overcharge. A nonstop trickle charge over 4.05V per cell would cause plating of metallic lithium that could direct to instabilities and negotiate protection. As an alternative, a brief topping charge is given to compensate for the little self-discharge the battery and its shielding circuit consume. Depending on the battery, a topping charge possibly repeated once each 20 days. Normally, the charge knocks down when the open terminal voltage falls to 4.05V per cell and turns off at a high 4.20V per cell.

What happens if a battery is unintentionally overcharged? Lithium-ion is designed to work safely inside their standard operating voltage but become unsteady if charged to greater voltages. When charging over 4.30V, the cell makes plating of metallic lithium on the anode; the cathode material turns into an oxidizing agent, loses steadiness and discharges oxygen. Overcharging makes the cell heat up. If left unattended, the cell could explode with blaze.

Customers Reviews:

Many customers’ reviews represent that Tenergy Multifunctional Charger for Li-ion Cylindrical Rechargeable Batteries (14500, 18500, 18650, RCR123A) is a smarter choice and really works good. It’s very useful because one can charge the 18650 batteries and the c123 ones as well. Other features include that it also informs through a light when they complete charging, one can also use a 12-volt adapter as if one wished to charge batteries in the car. It is user-friendly and done charging instantly in minutes. The charger accepts batteries of diverse lengths and the base contacts move up and down to accept batteries which are longer in size. The base contact is connected to a spring to give a safe grip on the battery. The charger at a time is capable of charging 2 x 18650 batteries. It can charge 1 battery at a time if that’s all one require.

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