Date:         Fri, 21 Dec 2001 09:02:36 -0500
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: A twist on dual-battery configurations
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 08:53 AM 12/21/2001, Jay L Snyder wrote:
>How about adding a second alternator for the second battery.  It could be
>adjusted to charge at a higher voltage if you are using a deep-cycle.

Sure.  Always good to have redundancy.  But until you address the
voltage-regulator problem the system is still fundamentally broken, so IMHO
better to spend the bucks there first.  To reiterate, an automotive-style
regulator is intrinsically incapable of *properly* charging any lead-acid
battery.  It can overcharge or it can undercharge depending on how it is
set (usually to undercharge).  For starting batteries this is acceptable
since starting batteries only use a few per cent of their charge at any
time except in emergency -- and in emergency it's considered acceptable if
the battery sacrifices itself to get you those last few miles.  For
deep-cycle batteries which are intended to provide "off-grid" (or
"non-running") power an automotive regulator is simply a way to ruin good
batteries while providing inferior performance.

TANSTAAFL...

david


--
David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"