Valve (One way valve) If the internal pressure of the battery is raised to an abnormal level, the rubber one way valve opens to release excessive pressure; thus the vent protects the battery from danger of bursting. Since the rubber valve is instantly resealable, the valve can perform its function repeatedly whenever required.
Example of Valve Construction
Rubber one-way valve
Built-in thermostat Some battery models (LC-SD122PU and LC-SA122R3AU) have a built-in thermostat. If temperature of the battery is raised by an overcurrent due to problems such as failure of a quick charger, the thermostat detects the increased temperature and shuts off current to secure safe operation. Even in an extreme case in which the both terminals of the battery are shorted, the thermostat serves to release battery energy intermittently, thus protecting the battery from hazardous conditions such as overheating.
Example of Thermostat Construction
Temperature of the hottest part of battery (˚C)
Charge : 0.4 CA
Charge : 0.8 CA
Charge : 1.5 CA
Temperature of Battery Overcharged
Temperature where the battery begins deformation
0120 Overcharge time (hours)