Date: Mon, 30 Jul 2007 07:54:15 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Deep Cycle Batteries
In-Reply-To: <46AD76E9.3050406@gmail.com>
Content-Type: text/plain; format=flowed
Ideally, the stock alternator-regualtor set up should be putting out 13.8
volts. Yes, they do drop a little after the alternator gets hot but that is
the set point. Many cars push to 14 volts or more.
The 13.8 is consered ny many battery folks to be the ideal compromise in
fixed voltage systems for flooded batteries.
Dennis
>From: Michael Elliott <camping.elliott@GMAIL.COM>
>Reply-To: Michael Elliott <camping.elliott@GMAIL.COM>
>To: vanagon@GERRY.VANAGON.COM
>Subject: Re: Deep Cycle Batteries
>Date: Sun, 29 Jul 2007 22:28:09 -0700
>
>Proper charging of a deep cycle wants a proper two- or three-stage
>charger (better). Good solar controllers do it, too. If I leave a
>campground in the morning w/o first charging up the battery w/ the
>panels, and rely on the alternator to charge the battery, drive a few
>hours, then check the state of charge, the battery monitor generally
>reports that I'm still 4 to 7Ah short of a full charge. This is with an
>adjustable alternator set to higher than stock voltage -- about 13.6V
>when temps are cool, 13.4V after driving for a while. Such voltages are
>too low to bring the deep cycle to full charge. Our controller applies
>current until the battery reaches 14.1V then chokes back the current to
>hold it there. After the controller is able to hold 14.1V with less than
>an amp for more than two minutes, the monitor declares the battery full.
>These alternators are not so smart. But I'm not complaining -- getting
>into camp with a battery that is 90% full is good enough for our use.
>
>And, as John said, Dennis knows his onions when it comes to this stuff.
>
>--
>Mike "Rocket J Squirrel" Elliott
>71 Type 2: the Wonderbus
>84 Westfalia: Mellow Yellow ("The Electrical Banana")
>74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
>KG6RCR
>
>
>
>Geza Polony typed:
>>Sorry to have hijacked this thread with my own aux battery probs, but I
>>hope
>>there's enough general info here for others to use.
>>
>>Interesting:
>>
>>On Sun, 29 Jul 2007 21:24:32 -0600, John <vanagonvw@GMAIL.COM> wrote:
>>
>>>if you
>>>invest in true deep cycle batteries, and don't use a three stage charger
>>>to keep them topped off, you are not getting the max life out of it, and
>>>in fact, are never getting it "filled up" in the first place. It may say
>>>100aH, but without the proper charge rates and controlled currents, you
>>>won't see those numbers in real life. These are not 'starter' batteries,
>>>and are not made to be bulk charged, with a constant dump of current
>>
>>In other words, just putting the Optima (or whatever) in and connecting it
>>to the relay, etc., is NEVER going to be enough to keep it fully charged?
>>That sounds like the problem here--it's never quite fully charged. (This
>>goes back even before my mishap with the espresso maker.) So to really get
>>the max out of a deep cycle battery, you have to use a separate charger?
>>I'll try it but sure seems like a PITA to have to do.
>>
>>If they're not made to be charged "with a constant dump of current," then
>>how can you connect them to our typical alternator/relay systems to good
>>effect?
>>
>>
>>>Just wanted to point that out....Dennis knows of what he speaks. Those
>>>who are paying for true deep cycle batteries, who want to take care of
>>>their investments, and get the most out of them, would do well to do
>>>some web work, and get the details on how to best take care of them.
>>>
>>>HTH,
>>>
>>>John
>>
>>Thanks, good post!
>>
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