2. Characteristics of SC Protector
2.1.1. Reliability of the protection circuit
All Li-ion rechargeable battery packs are
equipped with at least one protection
In this case, when an IC or FET breaks,
overcharge can’t be controlled any more,
www.datasheet4aun.cdomthe temperature rise of the battery
cell can invite very dangerous
thermo-runaway leading to smoking or
The trouble of the IC and FET actually
Therefore, double protection is needed to
ensure the safety of Li-ion battery packs.
Basic circuit with troubles
Overcharge = Danger
IC for protection
FET FET Trouble?
2.1.2. The weak points of conventional double protection elements.
Protection devices such as temperature fuses and bimetals work by conducting the temperature
rise in the battery to the inside of it via package or lead wire. Hence, they have a disadvantage
that the response speed is slow, and the response speed fluctuates depending on the installation
location of the device.
These elements obstruct a cost reduction since it is incompatible with the reflow soldering due
to their structures, and must depend on manual soldering.
By using SC Protector, the battery cells won’t become dangerous condition even if IC or FET breaks.
1) One device can protect against
both overcharging and overcurrent.
Double protection circuit using SC Protector
SCP protects from overcharge
and over current = Safe
2) Protection against overcharging is
directly performed by the battery cell
voltage, ensuring high accuracy and
quick response, and the response speed
does not fluctuate depending on the
location and condition of installation.
IC for protection
3) At the same time of protection
against overcharging, since it is
constructed to send current to the
heater via the fuse element, the fuse
element forcibly fused by the heating of the heater and, upon the cutoff of charging circuit,
the current to the heater automatically stops, and hence, SC Protector itself never
4) It is compatible with automatic mounting using general-purpose chip mounter, and at
the same time, compatible with the reflow soldering, contributing to the reduction of parts
SC Protector has the strong points as shown above and it meets the safety requirement without
spoiling the strong point of miniature of the Li-ion battery.