SLUUB65B May 2015 – December 2022
The fuel gauge can indicate detection of overtemperature in charge, overtemperature in discharge, internal short, and tab disconnect events. To enable overtemperature interrupts, the following conditions are required:
To enable internal short and tab disconnect interrupts:
If the OTC condition clears prior to the expiration of the OT Chg Time timer, then the Flags() [OTC] bit is not set. This setting depends on the environment temperature and the battery specification. This parameter needs to be set based on the temperature limits mentioned in the battery specification.
OT Chg Time is a buffer time allotted for overtemperature in the charge direction condition. The timer starts every time that Temperature() is greater than OT Chg and during a charge. When the timer expires, the fuel gauge forces an [OTC] in Flags(). Setting the OT Chg Time to 0 disables this function. Default is set to 2 seconds, sufficient for most applications. Temperature is normally a slow-varying condition that does not need high-speed triggering. It must be set long enough to prevent false triggering of the Flags() [OTC] bit, but short enough to prevent damage to the battery pack.
To recover from an OT Chg fault, Temperature() < OT Chg Recovery.
This is the only recovery method for an OT Chg fault. The default is 50°C, which is 5°C lower than OT Chg.
During discharge (Current > (–)Dsg Current Threshold)
Flags() [OTD] = 1 when Temperature() > OT Dsg for OT Dsg Time
If the OTC condition clears prior to the expiration of the OT Dsg Time timer, then the Flags() [OTD] bit is not set. This setting depends on the environment temperature and the battery specification. Verify that the battery specification allows temperatures up to this setting while discharging, and verify that these setting are sufficient for the application temperature. The default is 60°C, which is sufficient for most Li- Ion applications. The default OT Dsg is higher than the default OT Chg because Li-Ion can handle a higher temperature in the discharge direction than in the charge direction.
OT Dsg Time is a buffer time allotted for overtemperature in the discharge direction condition. The timer starts every time that Temperature() measured is greater than OT Dsg during a discharge. When the timer expires, then the fuel gauge forces the Flags() [OTD] bit to be set. Setting the OT Dsg Time to 0 disables this feature. This is normally set to 2 seconds, which is sufficient for most applications. Temperature is normally a slow-acting condition that does not need high-speed triggering. Set OT Dsg Time long enough to prevent false triggering of the [OTD] bit in Flags(), but short enough to prevent damage to the battery pack.
To recover from a OT Dsg Fault, Temperature() < OT Dsg Recovery.
This is the only recovery method for an OT Dsg fault. The default is 55°C, which is 5°C lower than OT Dsg.
Subclass ID | Subclass | Offset | Name | Data Type | Value | Unit | ||
---|---|---|---|---|---|---|---|---|
Min | Max | Default | ||||||
2 | Safety | 0 | OT Chg | I2 | 0 | 1200 | 550 | 0.1°C |
2 | OT Chg Time | U1 | 0 | 60 | 5 | s | ||
3 | OT Chg Recovery | I2 | 0 | 1200 | 500 | 0.1°C |
Subclass ID | Subclass | Offset | Name | Data Type | Value | Unit | ||
---|---|---|---|---|---|---|---|---|
Min | Max | Default | ||||||
2 | Safety | 5 | OT Dsg | I2 | 0 | 1200 | 600 | 0.1°C |
7 | OT Dsg Time | U1 | 0 | 60 | 5 | s | ||
8 | OT Dsg Recovery | I2 | 0 | 1200 | 550 | 0.1°C |