Design question for an electrical engineer.

[Kzrman]

I own a permanent backup generator for my home.
Recently I had to change out the 12 volt starting battery. When doing so I failed to notice that the positive and negative terminals were physically opposite from the one that was there before.
As I'm sure that you can guess, this fried a lot of the 12 volt components.
This got me thinking/questioning, why didn't the designers add in some sort of safeguards to prevent this from occurring?
What kind of change could one make to prevent this kind of destruction? Would adding something like a diode help?

Thank you in advance for your insights!

 

[Ostrichsak]

Maybe the engineers could devise a simple color code so that you could immediately tell the difference between the positive and the negative terminals at a glance. For instance, something like red for positive and black for negative should be easy enough to warn someone. Maybe even a symbol could be added that could act as a fail safe. Something like a plus sign "+" for positive and a negative sign "-" for the negative would be simple enough. To be sure that people who didn't know what they were doing didn't foolishly rush in w/o paying any attention to something that could ruin their car or potential even injure them they could even slap bright yellow warning labels all over the place just to get people's attention who had never done something like that before but foolishly opted to rush in w/o paying any attention to those other obvious signs. If we could get manufacturers to do all of those things then it would be nearly impossible for even a notice to mess that up, right? If only we could get the manufacturer to listen us to enact common sense warnings such as this situations like what happened to you would never happen again. When will the manufacturer care about the safety of the consumer?

 

[Kzrman]

Thank you for stating the obvious.
I freely admit my lack of judgement after the fact.

I wanted to go on a scientific curiosity expedition.
Anyone with a productive answer?

 

[bruce4000]

Yes adding a diode would allow only proper current flow although you loose 0.7 volts. I am surprised your unit was not protected against this as I know I have done that on multiple battery powered devices without problem.

 

[Kzrman]

Bruce4000: Thank you for the good information. I'm not sure why they didn't.
For some background, the generator is a Kohler 24RCL.
Here is a link to the part of the owners manual that has schematics in it. I would love to know what you think after looking at it.

https://resources.kohler.com/power/kohler/residential/pdf/tp6906.pdf

 

[NRVM3]

This generator has the capability to charge the battery as well. A protection diode would prevent this from feature from working. A much more complicated (than a diode) protection circuit would be required.

The question is why didn't the manufacturer label and warn against this? Not buried in the manual but rather clearly on the wiring associated with the battery.

 

[Kzrman]

Thank you for examining the circuit for me!

The manufacturer did label the cables going to the battery. I was supplied with a replacement battery that had it's connection posts physically opposite of what was there originally.