So I'm sitting in the X5, engine off, listening to the radio when I get a "battery severely depleted" message on the screen. Whoa, that's strange. Later, at home, I stick a VOM on the underhood charge points, and indeed, see the battery registers 12.0 volts. That's pretty close to flat, ie about 50% charge level, which is about the minimum you ever want to drain without damage.
So I stick a 10 amp charger on the battery and go have lunch. About an hour later, I come back and the charger reports almost full. So, yup, in about an hour, a 10 amp charger brought the battery up to 12.63 volts, pretty much full charge. Wait, 10 amp hours added to a 95 amp hour battery to go from 50% to 100%? Ummm, I believe it's time for a new battery. Not surprising, since that battery is now 9.5 years old.
So I stick a 10 amp charger on the battery and go have lunch. About an hour later, I come back and the charger reports almost full. So, yup, in about an hour, a 10 amp charger brought the battery up to 12.63 volts, pretty much full charge. Wait, 10 amp hours added to a 95 amp hour battery to go from 50% to 100%? Ummm, I believe it's time for a new battery. Not surprising, since that battery is now 9.5 years old.
