Originally Posted by rracer5
Also, if your battery is dead when you first hook up to your TV, the charge line from your trailer plug will start to charge your TT battery but, not as fast as a regular standalone charger or the converter in the TT once plugged into shore power. So........if the TT should break away from the truck, there most likely will NOT be enough charge in the TT battery to activate the trailer brakes properly if at all.
P.S. I used to take the positive cable off while in storage and took the battery off the TT and kept it at home connected to a "battery tender" during the winter.
Good advice on making sure the battery is charged before traveling.
You can disconnect either battery cable. However, It's always a safety issue and best practice on a negative ground system, to remove the negative cable first when removing a battery and connecting last when installing a battery. This way there is no danger of arcing across your wrench or rings on your finger as many people do if they touch something metal with the wrench/wratchet when removing the positive cable...if the negative cable is still connected. If you always remove the negative cable first or only, then you will not be in any danger if the wrench/ratchet comes into contact with some other metal while removing the positive terminal. Many a person has also burned themselves with their wedding bands this way too.
That's why I ALWAYS recommend just removing the negative cable in these situations and leave the positive alone.
An internet search should confirm this, if anyone doesn't want to accept my statement at face value.