41 President minor electric "leak"

[John DePrey]

The 8+ year old standard 6v battery in our President is toast. Never failed before and I've changed it out but it was completely dead. Before removing it I charged it a bit (still reads >6v) and then pulled the ground strap and connected an ammeter. She appears to be drawing 0.1-0.2 micro amps somewhere. Popped out the fuses under the dash and in the OD relay, no change. Where else might I want to look? 

 

Note she runs a 6v single wire alternator; the stock voltage regulator is still hooked up to the original wire harness. I'll keep looking but thought I'd ask here. Installing an Optima but the old lead acid one always worked fine. 

 

Yes I am using "she", we named her Eleanor, after the first lady when she was built, and my grandma too. 

[Gary_Ash]

Let's look at some math.  There are 8760 hours in a year, so 8760 hours x .0000002 amps = .0017 amp-hours, not enough to drain a battery any time soon.  Even if you meant 0.2 milliamps, that is still only 1.7 amp-hours in a year, not a lot.  However, standard lead-acid batteries do have an internal discharge rate, though you can't measure it directly, probably above 10% per month, especially for an old battery.  An Optima glass-mat battery will have a lower internal discharge rate, better when a car sits all winter.   

[Bloo]

Are you sure of the measurement? 0.1 micro amps is nothing. Also, one wire alternators, GM based ones anyway, draw all the time. It is a miniscule amount, but unavoidable. They are never completely "off". I would expect more current than you are measuring.

 

Systems that can shut clear off include generators, GM, Ford, and Chrysler alternators with mechanical voltage regulators, and Chrysler alternators with the 3-pin electronic regulator.

 

I suggest putting it on a battery maintainer. The self-discharge rate of an Optima is less than a regular battery, but still probably far exceeds what 0.1 micro amp would do.

 

I wouldn't want to lead you astray. Can you verify the measurement?  0.1 Amp = 100 mA (milliamps) = 100,000 uA (micro amps).

 

EDIT: @Gary_Ash posted while I was typing. He nailed it.

 

Edited May 6, 2023 by Bloo (see edit history)

[John DePrey]

it's a high end meter and it's micro-amps (I don't know how to get that mu symbol on my phone keyboard). When first measured it is near 1 micro-amp, drops quickly to 0.3 and within a minute is 0.1-0.2.

Yes I did the math and wondered if I should even worry but it did draw down what little charge the battery had in it... I rarely run a tender, I prefer to run/drive my cars and bikes at least monthly. All 3 bike batteries are over 5 years old, I must be doing something right. thanks gents