The first difference is that mains power is AC (Alternating Current) whereas batteries are DC (Direct Current).
The second difference is the amount of available amperage; mains have the capacity to deliver higher current for an indefinite amount of time, where batteries will drain faster the more current is pulled.
Your normal A/AA/C/D/9V batteries only produce 500 milliamps (1/2 an amp) at their nominal voltage (1.5 or 9v).
Mains current (for the U.S.) is 110 or 220 volts in residential. Commercial mains, such as in factories, can be 110, 208, 220, or 440 volts.
A big difference between residential and commercial electricity is the available phasing. But that's another discussion.
keyboard can use both
No, there was only Direct Current from batteries but no AC electricity as we know it today.
Something powered by household electricity rather than batteries
Mains electricity is typically more reliable and provides a constant power source compared to batteries, which can run out of charge. Using mains electricity can also be more cost-effective and environmentally friendly in the long run, as it avoids the need for constantly replacing disposable batteries. Additionally, devices powered by mains electricity can often deliver more consistent performance than those relying on batteries.
Mains supply provides alternative current while battery provides direct current.
Cells and batteries are portable and can be taken anywhere you go. Main electricity is stationary
Touching bare, live, contacts, connected to mains electricity will give you a nasty shock which could be fatal. Your house circuits have protection using circuit breakers, fuses and RCDs.Large batteries have the capacity to deliver very large currents if shorted out, which can cause fires and may explode, showering acid and/or chemicals all over the place.
The source for an electromagnet can be any electrical supply. Batteries or derived from the mains, using a transformed and rectified supply.
Portable devices that do not consume large amounts of power can be run on batteries. Some battery powered devices can also be powered by mains - running a 'battery eliminator' - to save from having to purchase batteries. Devices that consume large amounts of power are usually best powered by mains.
Mains electricity is nothing but main source of power in an installation. From the mains the power is then branched out to different end usage.
Everything that is plugged into the mains socket and switched on will use electricity even if it's a battery charger with no batteries in. So yes they do draw electrical power from the mains.
Batteries range in output voltage from 1.2 volts for an AA rechargeable, to 12 volts for a car battery. There may be other voltages, for special purpose applications. Batteries supply DC (direct current), meaning that the current will only flow in one direction.What is considered "mains" electricity (from a plug or receptacle in the wall) is alternating current (the current is oscillating between flowing one direction, then the opposite direction then back and repeats). It oscillates at 50 or 60 times per second, depending on what country you live in. Also the voltage is between 100 volts and 250 volts, depending on the country, as well. These features enable the voltage to be changed up or down rather easily with transformer, and allow the electricity to be transmitted over long distances.But the alternating current and higher voltages also make your mains electricity much more dangerous to touch than a battery. A person's skin has pretty good resistance to electric flow, especially direct current. But with alternating current, if you touch a wire, charges can actually form under the skin and start flowing through your body, because your skin acts as a capacitor. Then, the oscillating current back and forth through your organs is much more damaging, possibly causing your heart to stop pumping.