How to prolong the life of a lithium-ion battery technically explained

BT Waves Bluetooth Headset uses lithium-ion polymer battery.

Here is an extraction on how to prolong the life of a lithium-ion battery, with great technical explanation.

1. Avoid full discharges and charge the battery more often between uses, but do not keep it in fully charged status for an extended time.

Partial discharge on Li-ion is fine. A partial discharge reduces stress and prolongs battery life. There is no memory and the battery does not need periodic full discharge cycles to prolong life. Similar to a mechanical device that wears out faster with heavy use, the depth of discharge (DoD) determines the cycle count of the battery. The smaller the discharge (low DoD), the longer the battery will last.

Be aware though keeping the battery in fully charged status for an extended time can be more harmful than cycling.

2. Avoid exposing the battery to high temperature.
Lithium-ion suffers from stress when exposed to heat. Elevated temperature (above 30°C or 86°F) hastens permanent capacity loss.

3. For optimal performance, charge the battery at a voltage of 3.92V/cell.

High charge voltage also stresses lithium-ion batterys. For most Li-ion a voltage above 4.10V/cell is deemed as high voltage. Most Li-ions charge to 4.20V/cell, and every reduction in peak charge voltage of 0.10V/cell is said to double the cycle life. On the negative side, a lower peak charge voltage reduces the capacity the battery stores. In terms of longevity, the optimal charge voltage is 3.92V/cell. Battery experts believe that this threshold eliminates all voltage-related stresses; going lower may not gain further benefits but induce other symptoms.

(Technical source: http://batteryuniversity.com/…/how_to_prolong_lithium_based…)

How do BT Waves Bluetooth headphones achieve the noise cancelling effect?

Noise-cancelling headphones come in either active or passive types. BT Waves Blurtooth headphones use active noise cancelling technology that adds an extra level of noise reduction by actively erasing lower-frequency sound waves. The headphones actually create their own sound waves that mimic the incoming noise in every respect except one: the headphone’s sound waves are 180 degrees out of phase with the intruding noise waves.

The sound wave coming from BT Waves noise-cancelling headphones and the one associated with the ambient noise have the same amplitude and frequency, but their crests and troughs (compressions and rarefactions) are arranged so that the crests (compressions) of one wave line up with the troughs (rarefactions) of the other wave and vice versa. In essence, the two waves cancel each other out. The result: the listener can focus on the sound coming from the headphones.

BT Waves noise cancelling Bluetooth headphones

Get your personal 20% off coupon for BT Waves Noise Cancelling Bluetooth Headphones here.

4 tips for extending lithium-ion battery life

1. Keep your batteries at room temperature

That means between 20 and 25 degrees C. The worst thing that can happen to a lithium-ion battery is to have a full charge and be subjected to elevated temperatures. So don’t leave or charge your mobile device’s battery in your car if it’s hot out. Heat is by far the largest factor when it comes to reducing lithium-ion battery life.

2. Allow partial discharges and avoid full ones (usually)

Unlike NiCad batteries, lithium-ion batteries do not have a charge memory. That means deep-discharge cycles are not required. In fact, it’s better for the battery to use partial-discharge cycles.

There is one exception. Battery experts suggest that after 30 charges, you should allow lithium-ion batteries to almost completely discharge. Continuous partial discharges create a condition called digital memory, decreasing the accuracy of the device’s power gauge. So let the battery discharge to the cut-off point and then recharge. The power gauge will be recalibrated.

3. Avoid completely discharging lithium-ion batteries

If a lithium-ion battery is discharged below 2.5 volts per cell, a safety circuit built into the battery opens and the battery appears to be dead. The original charger will be of no use. Only battery analyzers with the boost function have a chance of recharging the battery.

Also, for safety reasons, do not recharge deeply discharged lithium-ion batteries if they have been stored in that condition for several months.

4. For extended storage, discharge a lithium-ion battery to about 40 percent and store it in a cool place

Storing the battery fully charged means oxidation of lithium-ion is at its highest rate. Storing lithium-ion batteries at 40 percent discharge and in the refrigerator (not freezer) is recommended

 

(source: techrepublic.com)