CMT CMT Battery & Power Management 2

Question 1

What is the recommended storage charge level for a Li-Ion battery if a device will not be used for an extended period?

Accepted Answer

Approximately 40–60%

Answer

Storing a Li-Ion battery at approximately 40–60% charge minimizes stress on the cells and slows capacity degradation during long-term storage.

Question 2

Which USB Power Delivery (USB-PD) feature allows a device to act as both a charger and a chargeable device?

Accepted Answer

Dual-Role Power (DRP)

Answer

Dual-Role Power (DRP) in USB Power Delivery allows a port to dynamically switch between acting as a power source and a power sink depending on what is connected.

Question 3

What unit is used to measure the rate of charge or discharge of a battery relative to its capacity?

Accepted Answer

C-rate

Answer

The C-rate expresses charging or discharging current relative to battery capacity; a 1C rate means the battery charges or discharges completely in one hour.

Question 4

What does the Battery Management System (BMS) in a smartphone primarily control?

Accepted Answer

Charging voltage, current, temperature, and cell balancing to protect battery health

Answer

The BMS monitors and controls charging parameters, temperature, state of charge, and cell balancing to protect the battery from damage and extend its lifespan.

Question 5

Wireless charging in smartphones most commonly uses which technology standard?

Accepted Answer

Qi (pronounced 'chee') inductive charging

Answer

Qi is the most widely adopted wireless charging standard for smartphones, using inductive coils to transfer energy between a charging pad and the device.

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CMT CMT Battery & Power Management 2