If the battery has fallen below to a critically discharged level, the system can enter a battery short identification process. A battery that is sufficiently discharged can be recovered if a low charge current is applied, however a battery with an internal short will not rise in voltage. We can take advantage of this behavior to help the identification of a battery short by monitoring the rise in voltage via BUVLO. A pre-charge current, specified by the battery manufacturer, can be applied to slowly charge the severely discharged battery. After a period of time charging can again be halted and a similar battery voltage check can be applied. If battery is still below the BUVLO threshold, this can be tried again. After a number of retries without the battery voltage rising above BUVLO, it is likely the cause of an internal battery short leaking the charge current. The system needs to be made aware of the behavior and charge needs to be disabled.

Figure 2-2 Short Test Flow