One volt is a joule per coulomb, therefore over time the battery looses electrical energy (joule) and this is why the battery becomes discharged.
put simply it is because the electrical energy is being consumed.
It should decrease
Cutoff voltage is the point at which the battery is fully discharged. This is usually the point at which the device will shut itself off.
Alternator is defective.
End cell voltage refers to the voltage level of a battery cell after it has been fully charged or discharged during a charging or discharging cycle. It is used as a measure of the state of charge or state of health of the battery. Fluctuations in end cell voltage can help diagnose battery issues or determine when a battery needs to be replaced.
Either you won't get enough voltage, and the car will stop once your battery is discharged, or you'll get excessive voltage, and you could end up actually overloading the battery and causing it to rupture, starting a fire, etc.
A C cell is fully discharged at 0.9 volts, 60% of the nominal 1.5 v.
A battery float charger is intended only to keep a fully charged battery from losing its charge. It will NOT work to charge a battery that is discharged or damaged. Check the voltage of the battery to be charged. Do not use charger if the battery voltage is less than 9.6 volts.
Changing the battery can affect the voltage depending on the type of battery used. If a new battery with the same voltage rating is installed, the voltage should remain stable. However, if a battery with a different voltage rating is used, it can lead to either an increase or decrease in voltage, potentially impacting the performance of the device. It's important to ensure compatibility to maintain proper functionality.
The normal test voltage for a fully charged 12-volt battery is typically around 12.6 to 12.8 volts. When the battery is under load, the voltage can drop to about 10.5 to 11.8 volts, indicating a discharge. If the voltage falls below 12.4 volts, the battery may be considered partially discharged, while a reading below 12 volts often signifies a dead or failing battery.
A 6-volt battery should ideally measure around 6 volts when fully charged. When the battery is under load or partially charged, the voltage may drop slightly but should generally remain above 5.5 volts. If the voltage falls significantly below this level, it may indicate that the battery is discharged or faulty. Regularly checking the voltage can help ensure the battery is functioning properly.
Cutoff voltage is the point at which the battery is fully discharged. This is usually the point at which the device will shut itself off.
Often it's a problem with a loose connection or corroded battery terminal, but it can also be just a discharged battery. The question is too vague to answer in any kind of detail, but it would be good to start with the basics; test the battery. Use a volt meter to see what voltage is present at the battery, then start to go out from there. If you have voltage at the battery, test voltage at the connectors, then the relay, then the fuse box.