I had a heated discussion with a few colleagues today revolving around how low of a voltage was alright for 12 volt lead-acid battery; they were in the opinion that the low voltage warning buzzer and ultimate automatic shutoff was annoying and a safety risk.
- I had one guy insisting that the batteries were 'fine' even when they had been seriously undervoltaged and you can throw pretty much anything at them.
- Another guy insisted his car battery had at some point been as low as 2 (!) volts and hey, he had no problems with it.
I've always thought when boating that you never let your 12 volt battery drop under around 11 volts, so this very passive stance has confused me a bit. Is there data available to quantify a loss in lead-acid battery quality from low-voltage events? How much do I lose capacity-wise from a low-voltage event? I'm fairly certain I'm right but I need some data.