Date:         Wed, 16 Jun 2010 15:02:07 -0700
Reply-To:     Karl Wolz <wolzphoto@Q.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Karl Wolz <wolzphoto@Q.COM>
Subject:      Re: 12.2 V at rest ('85 Westy w/2.1L)
Comments: To: Loren Busch <starwagen@GMAIL.COM>
In-Reply-To:  <AANLkTimKKsbH5qcqfX28fwHsNT_AbxcOwfhxdOjKm-o_@mail.gmail.com>
Content-Type: text/plain; charset="us-ascii"

Understood and agreed with.  Right now I'm not getting around (ruptured
achilles tendon repair), so I'm not getting into opening the battery box.
The little plug-in meter does give me 13.6 as soon as the engine is started.

|-----Original Message-----
|From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
|Loren Busch
|Sent: Wednesday, June 16, 2010 9:20 AM
|To: vanagon@GERRY.VANAGON.COM
|Subject: Re: 12.2 V at rest ('85 Westy w/2.1L)
|
|On Wed, Jun 16, 2010 at 7:43 AM, Doug Alcock <doug.alcock@gmail.com> wrote:
|
|> Try putting a Voltmeter on the battery and seeing if it agrees with your
|> plug in meter. It might be reading a tad low..........
|>
|
|Doug has made the point I was going to make but I'll belabor it  a bit.
|The
|only way to get an accurate reading of the voltage level of the battery is
|to measure directly at the battery itself.  There will be 'line loss' if
|taking the reading at some point like the cigar lighter.  That said, the
|loss will be constant (assuming a good, consistent connection at the
|lighter
|and that is not a good assumption) and the reading you see will be a good
|indicator or battery and (when the engine is running) charging state.  I
|have two of the little plug in gizmos, one about 40 years old (an actual
|analog meter instead of LEDs or a LCD readout) and they are great for
|getting a read on the battery and charging system especially in a vehicle
|that does not have a volt meter built in.  But the volt meter I have in the
|'cabin' for watching the state of either the aux battery or the starting
|battery (a switch controls what goes to the meter) is hard wired and then
|adjusted to read the same as my Fluke reading the batteries right at the
|battery.
|BTW, a 'perfect' battery is going to settle out at about 12.5-12.6 volts
|after the engine is off for a half an hour or more, assuming no load on it.
|Anything from about 12.2 v or above is what you will normally see.