Date:         Sun, 9 Aug 2009 20:40:20 -0700
Reply-To:     mark drillock <mdrillock@COX.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         mark drillock <mdrillock@COX.NET>
Subject:      Re: Battery charging question... will this work?
In-Reply-To:  <029501ca1964$82d0b3a0$6501a8c0@PROSPERITY>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

He said he did not have an aux battery installed yet. His questions
related to charging the main battery that he ran flat while camped.

His best path would be to install an aux battery. Then his other
questions would not matter much. Then he could camp and mistreat the aux
battery and still be able to self recover. Even just taking along an
extra fully charged battery in one of the battery boxes under the front
seats would do the trick. If you happen to run down the main battery,
use jumper cables to connect the good spare to the main battery, start
the engine, charge both for a few minutes, then unhook the spare and
drive away. I often take a spare with me to use in this way when I take
a trip with a Vanagon with only a main battery wired in. If need be I
will swap the 2 batteries to get started again, since jumper cables can
absorb a lot of the battery energy and there may not be enough left
passing through to start the engine with.

To use the digital charger on the flat battery the jumper cables can
help there too. Hook the too dead battery to another vehicles battery
with jumper cables. Run the other vehicles engine for a few minutes to
put some charge into the dead one. Then hook up the digital charger to
the slightly refreshed one and hope it works. If not, use the jumper
cables again to combine both batteries to get the digital charger
started. After a while unhook the cables from the other battery so the
charger keeps charging only the flat one. Never run the engine with any
charger hooked up unless it says in the charger manual that you may do so.

Mark

Scott Daniel - Turbovans wrote:
> my thoughts.........
> I am not the ultimate battery guru, or aux battery systems charging guru.
>...................
>
> I would say that the first issue is running your aux batt dead flat. My
> advise is just don't do that,
> unless it's a special battery of a different type built to take that.
> Normal batteries suffer permanent damage from being run down to dead flat.
> They were never designed for that.
> ..........
> Scott
> ----- Original Message -----
> From: "Jim Felder" <jim.felder@GMAIL.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Sunday, August 09, 2009 6:58 PM
> Subject: Battery charging question... will this work?
>
>
>> This is related to the question about digital chargers I posted last
>> week.
>>
>> I was recently camped in the same spot for four days, running lights,
>> fans, sink, rechargers, stereo, etc. and finally ran the battery down
>> so low it wouldn't run the clock. So low that my digital charger did
>> not even sense that it was hooked to a battery. It failed to charge.
>> My friends sharing the site pulled out a big analog charger and
>> charged my battery right up. But they have a huge van they pull a boat
>> with, I don't want to carry a huge heavy charger if I can help it.
>>..............
>>
>> If a 300 amp charger won't do the job, what would be the minimum setup
>> to let the digital charger know there is a battery there to be
>> charged, and how must it be hooked into the system? I'm thinking of a
>> very small 12v battery, maybe two lantern 6v cells, to provide the
>> necessary capacity for the digital charger to sense.
>>
>> What I really need to do is get my second battery and hella relay
>> re-installed but what to do till then? And, is there a reasonable way
>> of installing a smart charger so that the battery is continuously
>> being charged when shore power is plugged in?
>>
>> Thanks,
>>
>> Jim
>