Was the battery new or just charged? An old battery will reach a point where it will only take a surface charge and will start the car fine but go dead in a few hours. Have the battery tested most auto parts stores do this free. If it is good the have your alternator tested to make sure it is charging. Many auto part stores will do this for free also. If it is, then the real fun starts, finding the short. to find a short get an amp meter and hook it up between the neg battery terminal and the (removed from battery) negative battery cable with the car shut off. It should read less than .5 amp draw, any higher will drain the battery pretty quick. If above .5 amp have a friend remove fuses one at a time and watch the meter when it drops you have found the circuit, trace wires etc. on that circuit to find the short. A common problem with batteries going dead when a car sits is a glove box light, or trunk light that fails to go out when they are closed.
Something is on draining the battery or it has a dead cell and needs replacing.
If your battery is good and you know your car is draining it then yes, disconnecting your battery from your car will keep your battery charged for much longer than 3 days. Your battery should stay charged way longer than 3 days in normal conditions being hooked up to your car. You should get it checked out and figure out what is draining your battery so fast.
It depends on the type of battery, and the capacity of the battery, and the application you are using the battery for.
If it has a good battery that is fully charged when it is parked it will hold it's charge for 3 weeks with no problem.
Something is draining the battery. Check all lights. Glove box, trunk, etc. Also check the power window switch.
you should go to a car shop and get your battery checked and ask how long should u charge your battery.. or if you should get a new battery
The firs time the FitBit is charged it can take up to 4 hours to charge the battery completely.
The obvious answer is that your battery is bad and does not hold a charge. This happens to all batteries in time. Often, before they die completely, they run down quickly and only hold a charge for a few hours. If you have a new battery, something, no doubt a short in you electrical system is draining your battery.
Assuming the battery is good, you have a short somewhere in the electrical system that is draining your battery. You can confirm this by disconnecting the battery each time it is parked. If that solves problem, a short is confirmed. A professional has the devices to locate the site of the short.
If it is completely charged and you keep charging it, yes.
Could be the life of the battery has expired or the charging system is faulty or the vehicle has a draw on the system killing the battery when not running. Drive the vehicle to your local auto parts store. They will test the battery and the charging system at no cost. Battery is bad or something is draining it. Most places that sell batteries can check it. With it charged, disconnect it and see if it holds a charge. If it does, something in the car is draining it. Dead cell in the battery or something is on drawing power from the battery.
It probably needs a new battery. When you start charging a phone that is still half charged it takes a small bit of capacity out of the battery. Take it to the dealers and have them look at it.