Charge battery on 2000 300M

A bad battery can either take charged but dishcharge itself or it wont take full charge or it will charge but doesn't provide enough current to crank the engine.
Even new battery can be damaged if left uncharged for a period of time. If the car will not crank because the battery has been drained maybe by playing the radio too long. Jump start the car and let it charge. Or even better use a battery charger. Do not wait till the next day to jump start it because the battery will inquire damage. If the car was ok then all of the sudden it wont start in the morning and you know there is nothing in the car draining it, That means the battery has an internal short. It needs replacement. It will charge again after boosting but it will give you same problem over and over. Whats more the computer can be damaged by too much jump starting. It can also be damaged by a bad battery. If your car wont start and it has roughly 12.6 volts which is the voltage for a fully charged battery, that means the battery is also bad. In eliminating the battery as the culprit all connection must be clean and dry. Grease on the post used to prevent corrsion can lead to poor contacts.