Date registered: Jan 2004
Vehicle: 99 E320
Location: seattle, wa
Mentioned: 7 Post(s)
Quoted: 210 Post(s)
"...he's dead, Jim" that's what I found when I went to check on my car several
days ago. I have been so busy this Summer I skipped a periodic trickle charge
or two. pulled the Fluke 82 and it read ".018" volts.
since this was severe enough a discharge it warranted an inspection of the
battery. I pulled it out and popped the caps. acid level looked a scootch low
so I filled it just below the filler tube and placed it on the charger.
after a couple of days (and several checks) it appears good. specific gravity
density also good and no goobers seen on the top edges of the lead plates.
initial voltage check reads 13.12. I will monitor this for the rest of the day
and take it out for a long drive.
update 1 week later:
in the days following the battery recharge, the voltage readings were consistent
and remained high. BUT! ... i figured out how/why the battery drain likely occurred.
I considered a black box/module not going to sleep though if it had, it would have
been the first time.
Secondly, since the voltage readings after charging remained high, the symptoms
of a parasitic drain should have resurfaced but it didn't.
Well, I think I know how the battery drained to .18 VDC.
I normally apply a tapering charge every month. The previous time, I placed the
metal Craftsman 10/50 amp atop the engine manifold case so the puppy wouldn't
get to it. That was a mistake. Though the manifold cover is plastic, the charger
apparently was jostled to where the charger's metal chassis touched the magnesium
I tested this theory just now by popping the Fluke between the manifold and the "+"
terminal post in the engine compartment. walla, 12.7 volts. In effect, I had been
charging the battery...yet at the same time, I was shorting it out.
I also performed a continuity check between the exterior of the charger to the tips
of the POS battery clamp = .8 ohms
So let this be a lesson to anyone who still has an old school battery charger with a
metal clad exterior. Place a sheet of insulation (plywood, rubber mat, etc) between
the charger and the engine manifold
I always check the voltage immediately after charging but the 12+ volt reading a
couple months back was just a surface charge reading.
Last edited by raymond-; 07-21-2018 at 11:45 AM.