ATEVK527 Atmel, ATEVK527 Datasheet - Page 5

• Manufacturer Part Number: ATEVK527
• Description: KIT EVAL PWM AVR USB 4 SERIES
• Manufacturer: Atmel
• Series: AVR®r

Specifications of ATEVK527

• Main Purpose: Power Management, Battery Charger
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ATmega16U4, ATmega32U4
• Primary Attributes: 1 Cell- Li-Ion
• Secondary Attributes: Graphical User Interface, USB Interface
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.2 Charging Li-Ion Batteries
3.2.1 Safety
3.2.2 Priming & Charge Intervals
7801A-AVR-06/08
The electronic protection circuit works as follows:
• A solid-state switch is opened if the charge voltage of any cell reaches a given
• A fuse cuts the current flow if the skin temperature of the cell approaches 90°C
• The current path is cut when cell voltage drops below a given threshold. This is in
Today, lithium-ion is one of the most successful and safe battery chemistries
available with billions of cells being produced every year.
There is only one way to charge lithium-based batteries. Manufacturers of Lithium-Ion
cells have very strict guidelines in charge procedures and the packs should be
charged as per the manufacturers "typical" charge technique.
Li-Ion batteries are charged using constant voltage (after having reached the nominal
charge voltage), with current limiter to avoid overheating in the initial stage of the
charging process. Charging is terminated when the charge current drops below a
threshold set by the manufacturer. Several parameters are monitored during the
charge: charge time, battery temperature… The battery takes damage from
overcharging and may explode if overcharged.
Static electricity or a faulty charger may destroy the battery's protection circuit and
turn solid-state switches to a permanent ON position. This may happen without the
user knowing. A battery with a faulty protection circuit may function normally but does
not provide protection against abuse.
Consumer grade lithium-ion batteries cannot be charged below 0°C (32°F). If charged
at cold temperatures, battery packs may appear to be charging normally but chemical
reactions inside the cells may cause permanent damage and can compromise the
safety of the pack.
The battery will become more vulnerable to failure if subjected to impact, crush or
high rate charging.
The battery must remain cool. A battery pack that gets hot during charge should not
be used.
Unlike many other types of rechargeable batteries, Lithium-Ion batteries do not need
priming. The first charge of a Li-Ion battery is no different than the 10
charge.
Lithium-ion batteries may be – and should be – charged often. The battery lasts
longer with partial rather than full discharges. Full discharges should be avoided
because of wear.
The battery loses capacity due to aging, whether used or not.
threshold.
(194°F).
order to prevent the battery from over-discharging.
AVR146
th
or the 100
5
th