Comment 4 for bug 427289

The patch will not show instant results, as it simply enables the button battery to be charged. The button battery holds the RTC running when power is removed so you need to allow the battery to charge for some time (likely 8-10 hours) before it will hold the clock alive.

There is also some chance that the battery is dead beyond charging so we may need to replace them. Might be worth testing by pull the button battery out record it's voltage, then replace it, give it time to charge, pull it out again and check it's voltage again and see if the battery has taken any charge, if not we could/should replace the battery and see if the charging circuit can maintain the battery over time.