I use my car once every week or other week for 30min drives off course that is bad and damaged my car battery, the question is can I now revive this dead battery ? it failed me today I jumped started it then drove for 30 min and it won’t start again I put it in a battery charger it went from 11 v to 13 v in less than an hour with very low current but after an another hour sitting in my garage the voltage dropped to 12.6 V without even being connected to the car !
12.65 volts is a full charge…
12.45 volts is a 3/4 charge
12.25 volts is a half charge…
i hook up the battery and turn on the headlights for a minute. then turn them off. then read the voltage…
see my test chart… https://i.imgur.com/SnzhDh0.jpg