I am wondering what happens when you have accidentally connected the negative cables to positive and the positive cables to negative. I have boat that has to two marine batteries and i am wondering if you were to do this will it screw things up and break things?
You COULD fry any electrical items such as a radio or navigation equipment. And DC motors will turn the opposite direction which may or may not be a bad thing for whatever the motor turns. You DO realize the posts on the batteries are different sizes, yes? Generally the negative clamp will not fit on the positive post and the positive clamp can't be tightened enough to make a tight contact on the negative post. Your batteries MAY be different however, depending on how the cables attach, so the post size is not always an indicator that it should be.
Hmmmm The only approach to comprehend for sure if that fried the the circuits could be to check out it out with the proper adapter. I would now not use the adapter with the overrated voltage, why danger it extra? Just take the one you firstly used, reduce the output cable and splice the wires collectively the opposite method to reverse the polarity of the plug. That would clear up your main issue.
It depends on the details of how you mis-wired the batteries and what equipment you tried to run with the batteries mis-wired. Many devices have some built-in protection against reverse polarity, so there might not be any damage at all. If you mis-wired between the batteries, you could have damaged the batteries. If you wired them so that they were in series, you doubled the voltage on things that were connected. Light bulbs, starter motor/coil in the boat motor, electric motors will probably survive a short time in that configuration, but their lifetime is probably shorter now.
YESespecially if you have anything greater than a brief contact. Car and marine batteries are designed to deliver a huge amperage (that is why jumper cables are so thick) for a relatively short time. The best thing is to use a automatic battery charger used for car batteries which usually has a reverse polarity light on them that flashes or beeps if you accidentally hook up the cables backward. Or hook a multimeter to a known battery , like a AA battery with the positive terminal labeled, and put the red lead of the multimeter to there and the other lead to the other end of the AA battery. If the digital readout is positive 1.5V or so then measure the marine batteries with the same red lead and if the multimeter shows a positive direction then you know you have the positive terminal. If the multimeter has a negative voltage, then you know you have to reverse the cables
