Which Battery Terminal Is Connected First. Then connect the black cable to the negative terminal. Doing so will create a short since the negative terminal is grounded to the frame and fuses will pop tools can melt and the battery could explode.
How to connect a battery charger. You should always remove the NEGATIVE terminal cable first. When charging multiple batteries connected in parallel batteries in the string will receive the same charge voltage but the charge current each battery receives will vary until equalization is reaches.
For the same reason I would disconnect the negative connector first too.
These standalone units connect to your cars positive and negative battery terminals. A friend of mine told me that I should always disconnect the positive terminal of the battery first to keep the electricity from spilling out of the battery. For the same reason I would disconnect the negative connector first too. Likewise the negative terminal of the first battery is connected to the negative terminal of the second battery.
