Disconnecting Battery - wow! big spark
Hi all, dh put our fiver in storage for a little while and disconnect the battery. There was big spark signifying quite some power still running in the rig even tho everything was turned off! His...
Forum Discussion
boogie_4wheel wrote:4x4FF wrote:wgriswold wrote:
How would removing the ground cable first negate any sparks?
It has to do with current flow. You will almost never get arcing when disconnecting the ground first even if there is a dead short.
Steve
That doesn't make any sense to me. Arcing is a result of difference in voltage potential and load. If there is an electrical load in the trailer and you pull a battery cable, you will get the same amount of arcing from the pos or neg post. If no electrical devices are on, then no arc (regardless of which is pulled first).
The only reason to pull the neg cable first would be so that the tool(s) used on the clamp/post would not ground the battery if they were to contact the trailer frame. If you were to contact the frame from the positive side AFTER the neg cable is removed, the circuit is open and no arc, making this the safer practice.
That is exactly my understanding. A spark will appear if the electrons are flowing out of the negative or into the positive terminal.
I get a small spark from about a 0.6 amp flow even when everything is disconnected in the trailer. Some experimentation showed that the primary culprit was the radio with a 0.4-0.5 amp flow and the rest was due the various detectors. Two weeks of storage at that rate of discharge would have depleted my batteries.
It was a pain to get to the batteries to disconnect them for storage so I installed a marine battery switch.
