It takes a lot of time to charge a really dead battery. When you try and start the car with a dead battery installed there is a large voltage drop across your jumper cables so you must achieve a reasonable amount of charge on the battery before you can turn over the engine even with the jumper helping. If you are losing charge on your battery in a short period of time you may have a failed voltage regulator, a bad battery, a bad alternator (should be putting out 14 volts DC or so) or bad connections. You could replace the battery (with a charged one) as a test to determine that the car will start. If it starts OK than read the voltage on the battery terminals while the car is running to check the alternator and regulator.
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It takes a lot of time to charge a really dead battery. When you try and start the car with a dead battery installed there is a large voltage drop across your jumper cables so you must achieve a reasonable amount of charge on the battery before you can turn over the engine even with the jumper helping. If you are losing charge on your battery in a short period of time you may have a failed voltage regulator, a bad battery, a bad alternator (should be putting out 14 volts DC or so) or bad connections. You could replace the battery (with a charged one) as a test to determine that the car will start. If it starts OK than read the voltage on the battery terminals while the car is running to check the alternator and regulator.