Summarize this article in one sentence.
To manually jumpstart a dead phone battery, you will need: A 9-volt battery Electrical tape 2 electrical wires: Basic, thin electrical wire will do. Red (+) and black (-) are preferred. Be very cautious when dealing with electrical circuits. If you don't know what you're doing, it's always better to be safe than sorry. Overheating your battery or making wrong electrical connections may be extremely dangerous, and even explode your battery. You will usually have to open the back of your phone or the casing in order to remove the battery. The positive end is the smaller hole at the top of the 9-volt battery. Connect one end of your two wires here, and tape it with electrical tape for a secure connection. You can find a "+" sign on the positive side of the battery. The negative end is the larger hole at the top of the 9V battery. Make sure to securely connect and tape your second wire here with electrical tape. You can find a "-" sign on the negative side of the battery. The positive and negative ends are usually labeled with "(+)" and "()" signs on the battery's casing. If you're not sure which end is positive or negative on your phone battery, make sure to consult to the manufacturer's manual or a professional electrician. Most cell phone batteries have more than two terminals; use the ones that are furthest from each other or the ones on the outside. The center terminals are not to be used. Take the wire connected to the 9V battery's positive end, and connect the wire's other end to your phone battery's positive (+) socket. Remember to use two separate wires or split wires for each of the terminals. Do not connect the positive and negative terminals of either battery with itself. Do not connect opposite polarity, positive to negative, because this can short-cut your cell phone battery, and cause damage, or even a small explosion. Take the negative wire connected to the 9V battery's negative end, and securely tape its other end to your phone battery's negative () socket. This will be enough for the battery to jumpstart and charge a little. Make sure check the battery every 10-seconds, and make sure it doesn't overheat. When your battery is getting a bit warm, you can remove all the wire connections. Make sure to properly insert your battery into your phone's battery compartment. After jumpstarting with a 9V battery, check to see if your phone turns on, and check the battery level to see how much it charged the battery. You can try charging your phone with your regular charging cable now.
Gather the required supplies for jumpstarting a battery. Remove the battery from your phone. Connect and tape one wire to the positive (+) end of the 9-volt battery. Connect and tape the other wire to the negative (-) end of the 9-volt battery. Find the positive (+) and negative () sockets of your phone battery. Connect the positive wire to your phone battery's positive (+) end. Connect the negative wire to your phone battery's negative () end. Leave the connection on for 10 to 60 seconds. Remove the wire connections on the cell phone battery. Insert the cell phone battery back into your phone. Turn on your phone.