Yair . . . .
Perhaps your luck will change? Why chance it?
Ever since electric welders have been used on machinery it has been convention to unhook the battery.
In the days of generators on equipment voltage regulators were the vulnerable component and could be fried with random inexplicable feedbacks.
Complete bull$hite mate. There may be no "reason" for it to go anywhere else but it can.
Even with the earth clamped onto a track-plate and welding the track plate to the link I have seen arcs at random points along the track chain . . . seems impossible but it happens . . . as do random arcs and flashes in the broken canopy wires of tractor as welding is being done on the blade.
And trust me you get some really strange things going on if some one forgets to move the earth when welding on hundred foot steel boat . . . or particularly if the earth gets knocked off and you continue to work with the clamp hanging in the water adjacent to the hull. . . what is a side scan sonar worth?
Cheers.
So what does unhooking the ground from the battery protect other than the battery? Everything on the machine has it's own ground somewhere other than than the battery. They ground either to the chassis or the engine block. For unhooking the battery to help, the current/noise that damages something would have to pass through the battery. I'm not trying to argue or call BS, just doesn't make sense to me.
If you really are concerned about modules, components and ECMs they should be disconnected entirely. That's the only way to properly isolate them.
But if you have a poor ground like on something with a little rust, your ground clamp is dirty or blackened from arcing or you are grounded to a different peice of metal I can definitely see it trying to get to earth through another path or multiple paths if the one with the least resistance doesn't have enough current capacity.
The sonar example is an improper ground example but even then I don't think unhooking the battery would save it. You have the current trying to run out the transducer to the floating ground clamp and finding a path through whatever it can along the way. I don't see why it would try to pass through the battery.
I like to try to understand how things work, especially electricity, I do a lot of diagnostics and I have learned that blindly following directions isn't always the most efficient path and can sometimes get you screwed. They aren't always right. I'm not saying uhooking a battery is going to hurt anything, and in some bad ground cases it may help, but on the stuff I work on it can directly cost you money and or an unhappy customer. We once put a battery in Volkswagen that we had to have towed to the dealer because the transmission no longer worked, it needed to be reprogrammed. lesson learned, use a memory saver. But what's the difference in using a memory saver battery and leaving the cars battery hooked up when welding? None really if you are trying to protect components. Now we have clocks to reset, radio and navigation security codes to deal with and a host of driver settings that may or may not need resetting, not to mention ecm relearning. Unhooking a battery isn't as simple as it used to be, it can take an hour of extra work and sometimes calls to the dealer to get security codes...who wants to deal with all that if it not necissary?
