Battery Charging Numbers

[Guest]

Charged my battery last week and left it disconnected before going on a business trip. It's been just short of a week and the battery is holding at 12.65v. This is good, right?

[Jethro]

I recently learned that a normal lead acid battery is 100% charged at approx 12.7 volts, and 50% charged at 12.4 volts. A battery at 12 volts is completely dead. What I don't understand is why they call it a 12 volt battery? Whatever.

[Boondocks]

Charged my battery last week and left it disconnected before going on a business trip. It's been just short of a week and the battery is holding at 12.65v. This is good, right?

Yes, this is good. Keep it under surveillance if not in use, since batteries (especially flooded with filler caps) normally self discharge and will have to be charged periodically if not used.

I recently learned that a normal lead acid battery is 100% charged at approx 12.7 volts, and 50% charged at 12.4 volts. A battery at 12 volts is completely dead. What I don't understand is why they call it a 12 volt battery? Whatever.

Would you prefer that a battery was called an "approximately 12.7 volt when fully charged battery"? The nominal description of 12 volt battery is used to denote the six cell battery class and not to describe the fully charged voltage.

[UncleMike]

So now, and believe me I feel like an idiot for having to clarify this so many times, I want to check for parasitic draw.

I should reconnect the positive battery cable to the positive battery terminal, but leave the negative cable disconnected, and then set my multimeter to dc volts, and connect the negative probe of the multimeter to the negative terminal of the battery and the positive probe of the multimeter to the negative battery cable and check for any draw?

[UncleMike]

When doing the above, positive cable connected to battery, negative cable disconnected, negative probe of multimeter connected to negative battery terminal and positive probe of multimeter connected to negative battery cable, I got a reading of .0055v when the multimeter was set to 20vDC.

Problem?

[earlfor]

That is good to go Mike. :-)

Earl

Charged my battery last week and left it disconnected before going on a business trip. It's been just short of a week and the battery is holding at 12.65v. This is good, right?