Hi all electrical engineer, I've got a mystery. My 2 6 volt and 1 12 volt batts all passed hydrometor test and showed 12.5 volts yesterday. Put them in my car last night, brought them to the boat today and installed the 6 volt ones first. Nothing, volt meter on panel showed nothing. Checked with my multimeter, nothing.
Tried the hydrometer and passed, fully charged
Checked the 12 volt batt sitting on thr cabin floor with multimeter. Nothing.
Thoughts, before I go off and buy new ones?
Thanks
Ed : I'd have your hydrometer checked before I did anything.
With the batteries installed does the engine start OK? and the rest of the electrical equipment act OK?
A few thoughts
Ron, no as I mentioned, nothing works, volt meter on electric panel doesn't budge either. I'm getting new batteries. I'm more interested in how batteries can look good via hydrometer and multimeter one day and the next day be dead.
Ed,
How old are the batteries? I'd take them to an auto parts store and have them load tested, at least the 12 volt. I usually use my batteries for about 3 years then replace them.
As scgunner noted, the load test would be critical to finding out if they are any good. A battery can take a charge and register a good resting voltage, but once a load is placed on it, fall flat on its face. I am a bit curious how they were showing 12v the night before, but became dead flat by morning.
That was my question too Alex and reason for posting. They are old,8+ years, so I've gotten my moneys worth. Not going to get them tested Kevin. Don't want to haul them around any more than I have too. Getting new ones. Just waiting for my local battery distribution center to get a new shipment in from there distribution center. Should be Monday.
Ed,
Good call, eight years is a hell of a run you definitely got your money's worth out of those batteries. Just curious in all that time did they ever not start the motor?
Yeah 8 years is pretty epic. I'd say you came out on the right side of that show!
Nope, never a problem
Ed : In your write up you should have told us that those batteries were 8+ years old!!!
I believeknow that our replies would have been different!!
A thought
I didn't intentionally avoid saying their age, I was more intent on understanding how uninstalled batteries could pass the hydrometer test and multimeter test one day and be totally dead the next. I wasn't even sure at the time of their age as my logs were on the boat and I was home.
Well it at least explains why the batteries don't have any "grunt".
Ed : That's the nature of lead/acid batteries. When they get an internal short they just roll over and die. My neighbor with a 2 year old Mazda, came back from the store (no problem) and a hour later the auto wouldn't start.
I put my meter on the battery and it read 3.2V!!
Typically you should get 4-5 years out of lead/acid battery. After that you are on borrowed time!!
A thought