After starting normally after sitting for a few days, warmed up, and then shut off or a few minutes. When attempting restart, dim dash lights and no start. Used a portable 600 amp jump, started very briefly running rough. Died when accelerator was let go and no restart. Attempted several restarts. Charged battery using a 10 amp charger and then used portable jump starter again Engine turned over but did not fire, slow spinning starter motor. Charger says battery is fully charged but still very dim lights and will not turn over on internal battery alone. Battery is less than three years old. Terminals looks clean and snug. Bosch battery. Thanks for any assist. 1993 BMW 525i
My car has 190000 miles.
My car has an automatic transmission.
It really does sound like your battery has gone dead. Sometimes they can develop an internal short where they seem fine one moment then go dead the next. The indicators on the chargers usually don't tell the whole story.
Additionally, I suspect your charging system may not be performing well as it's not able to keep the car running after you start. If you have a voltmeter, you can check the voltage across the terminals while the car is at rest and while the engine is cranking. A good battery should show 13.6 volts after charging and not drop below 10 volts while cranking.
Other explanations for the slow cranking could be a bad ground connection at the chassis or battery cable connections that have become dirty or corroded at the other end where you are not looking.
By contacting YourMechanic you can have a technician come to your home or office with all the necessary equipment to properly diagnose your cranking problem and help you fix it accordingly.
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