The definition of transfer time, sometimes also called switchover time, says it is the amount of time a UPS will take to switch from utility to battery supply during a mains failure, or from batter.
What is a switching time in a UPS (uninterruptible power supply)?
Switching time/transfer time in a UPS (uninterruptible power supply) is the time it takes to switch from the utility to the battery power supply. It is typically measured in milliseconds. The switching time is crucial because it determines how long the connected equipment will continue to operate without interruption when there is a power outage.
Why does my battery not work if the power supply is turned off?
And a freshly charged battery can have a higher voltage than 12.6V. In that case, the circuit will run on battery power. With my circuitry, your device will work longer when the power supply is turned off because a charged battery has more power than a battery discharged to 12V. Sorry I'm still not following why it won't work.
And holds a relay latched. When power fails, for the instant it can take for the relay to switch over - you can lose sufficient power and end up having to reset your equipment. Not so if you're not drawing a lot of current. A cap can possibly carry the changeover from the PS to the battery.
Short switching time is the key to a smooth transition from utility to battery power and battery to utility power. Switching time/transfer time in a UPS (uninterruptible power supply) is the time it takes to switch from the utility to the battery power supply. It is typically measured in milliseconds.
Once the under voltage trips, it tries to switch to the next power input, the one where you have connected your battery. It does this quickly, so your load doesn't see the voltage dropping very far. Once power comes back on the primary feed, it will automatically switch over.
What happens if you connect two batteries together on a switchover?
Inadvertently connecting the two batteries together on switchover causes inrush currents that overloads the contacts, so that's bad thing. Cheap relays, or relays that are worn out, also have a problem with the mismatch in the speed in which the contacts in the pair switch.