Date:         Mon, 12 Feb 2007 03:01:58 -0800
Reply-To:     Philip Zimmerman <philzimm1@OBERON.ARK.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Philip Zimmerman <philzimm1@OBERON.ARK.COM>
Subject:      Re: Batteries don't die, they get murdered
Content-Type: text/plain; charset=US-ASCII; format=flowed

Date:         Mon, 12 Feb 2007 00:08:08 -0500
From:         Dennis Haynes <dhaynes@OPTONLINE.NET>
Subject:      Re: Batteries don't die, they get murdered
Comments: To: David Etter <detter@MAIL.AURACOM.COM>

Dennis Haynes wrote:

I have written many posts explaining my thoughts on the Optima. I guess
I
was ignored.

> Ah sucks Dennis, I recall most of your excellent posts.
> Lost to some perhaps, in the dark recesses of the dreaded Archives.
> Good information deserves and even demands repetition. Keep it coming!

Sealed batteries are great in theory. Experience tells battery guys
otherwise. Unless you have an application that just can not accept some
off
gassing and a possible spill, (sail boat that may cap size), a
conventional
flooded cell will take more abuse, and outlast an AGM or gel battery.
The
main advantage of a normal battery is that when the electrolyte is
driven
off, water can be easily added. So called sealed batteries do have
vents,
(pressure relief), and once the solution wisp out, it is gone forever.

> I agree in part, that on-balance a quality wet-cell deep-cycle will
> perform as well as or better than a SLA/AGM of similar quality under
> most conditions. The higher quality SLA's with
> their heavy thick plates will provide better low temperature discharge
> capacities than a wet-cell but the costs are outrageous by comparison.
> AGM's offer toughness. Physically they are
> difficult to destroy, outlasting most wet-cells under extreme
> conditions of physical abuse.

> The charging of the three types, seem to me, the great leveller in
> this debate. Limiting our scope to Vanagons. SLA's are SOL IMHO. The
> current and voltage regulation is just not controlled enough and when
> mixed with a wet-cell starting battery, the SLA will die an early
> death. Separated by your favorite solenoid/combiner/separator/isolator
> the poor SLA will be cooked, albeit slowly.

> AGM's and Wet-cells are far more tolerant of a Vanagons crudely
> regulated charging circuit. Here is where I suggest the AGM may hold
> an edge. AGM's are capable of accepting very high charging voltages
> and near limitless currents (just don't cook it or the vents will go
> shhhut, as you have point out). Levels of Voltage and Current that
> would boil most Vanagon sized Wet-cells. Big but here, the Vanagon
> Alternator in stock form will not deliver these levels of voltage and
> current, even on a good day with the Headlamps, AC, BLower Fan and
> Stereo off!

> What appears left is how and what to shoehorn into a Vanagon? This
> seems a relatively subjective subject at best and at worst: "how I
> spent $400 on batteries" and still lack either the Amp-hours I need or
> where did all the storage space disappear? Your points on out-gassing
> need to be addressed also. Oh honey, why does my Mac & Cheese smell
> and taste like rotten eggs? Beats me says Rex, all I did was store it
> on-top those silly batteries YOU put in the the bed-storage box!
> Anyway, I can't hear you with the hair-dryer blowing in my ear. That
> 2000 watt inverter works real good dear! YMMV

Phil Z.