Date: Sat, 5 Sep 2009 22:08:58 -0700
Reply-To: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Subject: Re: Run time to charge Aux battery
In-Reply-To: <BAY132-DS39B14EA2E0CA7D51257ECA0EC0@phx.gbl>
Content-Type: text/plain; charset=windows-1252; format=flowed
Darn good point you got there.
Halogen lamps, I am told, fail quickly when overvoltaged. I heard
somewhere that the lifetime of a tungsten bulb is inversely proportional
to the 12th power of the applied voltage to the nominal voltage. So,
(12/15)^12=0.07, so if a bulb is rated for, say, 1000 hours at nominal,
its lifetime becomes something like 70 hours if operated at 15V.
Most power supplies for things like laptops and similar gear can handle a
25% overvoltage.
--
Mike "Rocket J Squirrel" Elliott
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
Bend, OR
KG6RCR
On 9/5/2009 8:20 PM Dennis Haynes wrote:
> One thing to consider with multi-stage chargers is that they usually only
> work with no load on the battery circuit during the charge process. There
> are exceptions but the finish and de-sulphation voltages can wreak havoc on
> light bulbs and anything sensitive downstream. 12 volt light bulbs don’t
> last long at 15.5 to 16 volts.
>
> Dennis
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Rocket J Squirrel
> Sent: Saturday, September 05, 2009 6:54 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Run time to charge Aux battery
>
> Or, put this 4-stage charger between your starter battery and your aux
> battery:
>
> http://www.sterling-power.com/products-battbatt.htm
> http://www.sterling-power.com/products-battbatt-install.htm
>
> The 50A version is £256.83 at
> http://www.the12voltshop.co.uk/Shop/battery-to-battery-charger-12v-to-12v-50
> a.html
>
> --
> Mike "Rocket J Squirrel" Elliott
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> Bend, OR
> KG6RCR
>
>
>
> On 9/5/2009 2:03 AM Malcolm Stebbins wrote:
>
>> I know very little about electricity! I checked the archives and I found
> this article, but it did not exactly answer my question:
> http://gerry.vanagon.com/files/motorhome/Motorhome-Alternator-Charging-Syste
> ms.txt
>> I have 2, 6 volt deep cycle batteries hooked up and I have about 200-ish
> amps (I think) in the aux batteries. This is used to run my Waeco fridge,
> which takes about 7 amps when it runs, but only runs about every 10 minutes
> for 2 minutes-ish.
>> Usually I only park for a day or 2 max, so all is OK with the aux
> battery, but this last trip I stayed parked for 4 or 5 days in a row, and
> the fridge's 'low battery' light came on.
>> My question is: APPROXIMATELY what is the charge rate IN AMPS for a nice
> good working system. I say good system as I have a new Zetec engine with a
> 100+ amp alternator and the wires are all new and the batteries are
> relatively new.
>> I use a SUREPOWER 1315 isolator for the 2 battery sets.
>>
>> When the battery got low, I took to idling the van for about 15 minutes in
> the morning, and again 15 minutes in the evening, to help the battery a bit
> and this seemed to help. Is this folly?
>> Thanks Malcolm
>>
>
>
|