Connect the capacitor’s positive terminal. Whether you are connecting to the battery, amp, or a distribution block of some kind, you need to connect the positive terminal of the capacitor to the positive terminal of the other component by running a wire between them. Eight gauge wire is usually recommended.
Once the capacitor is mounted, connect its positive terminal to the positive terminal of the battery using an 8-gauge wire. Then, connect the negative terminals and reconnect your battery's ground terminal to restore power to the entire system. For tips on how to charge a capacitor, read on!
It is fine to connect them when the output voltage of the supply and the voltage across the capacitor are close to each other. If they are not close to each other, you may get a spark at the moment you connect them. The spark can suprise you with the amount of energy it delivers.
Of course when you put a capacitor onto a battery like that, you will not make great contact, so there will be some extra resistance there as well, so it might even be 0.7A.
In my understanding, theoretically, when an uncharged capacitor is connected directly to a battery of, let's say, 9 volts, instantly the capacitor will be charged and its voltage will also become 9V. This will happen because there is no resistance between the capacitor and the battery, so the variation of current by time will be infinite.
When the meter reads 11-12 volts, the capacitor is charged. Another way to charge a capacitor is to wire a test light from the positive terminal of the capacitor to the power line. As long as the capacitor is charging, there will be current flowing through the light and the light will shine.