Date: Fri, 21 Aug 2009 12:37:43 -0400
Reply-To: Kim Brennan <kimbrennan@MAC.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Kim Brennan <kimbrennan@MAC.COM>
Subject: Re: Engine electrical power requirements?
In-Reply-To: <4A8EB6DE.3020301@gmail.com>
Content-type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
A gas engine uses very little electrical power. Most of the amps are
for other things, such as fans, radios, lights. A standard battery
will run an engine for a long while.
A diesel engine will go even further, as once it is running, it
doesn't use practically any electrical power.
On Aug 21, 2009, at 11:01 AM, Rocket J Squirrel wrote:
> Yeah, well, I suppose the only persons who actually /need/ to know the
> power draw of the engine alone would be those whose alternator
> failed and
> they were looking at getting home on the battery and thinking,
> ". . . okay
> this is a 40Ah battery . . . I wonder how long it can power the
> engine?"
>
> That would be the ECU, fuel pump, ignition bits (coil und so weiter),
> various senders and sensors stuff; and not counting headlights,
> radio, etc.
>
> My interest is really on what your 90A Bosch alternator has left over
> after taking care of the engine.
>
> I recall that the engine in my (now sold) 71 aircooled baywindow could
> drain a battery pretty quickly and all it needed for power was for
> ignition. No ECU, the fuel pump is mechanical, there's not even a temp
> sender.
>
> Anyway, Mark Drillock provides the method to measure the numbers I
> need. I
> guess my in-depth article on aux battery charging -- which includes
> excellent calculations of wire sizes based on available power from
> such
> sources as your starter battery and alternator and takes into
> account such
> subtle matters such as internal resistance of typical lead-acid
> batteries,
> and which is intended to provide worst-case scenario for wire
> diameters
> and relay contact ratings, will just have to wait.
>
> Simply a tragedy -- a tragedy, I tell you!
>
> --
> 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 8/21/2009 5:50 AM Richard A Jones wrote:
>
>>> I am hopin' this is some bit of information that is commonly known.
>>
>> I asked the same question a couple of years ago and got nowhere,
>> so I'd say "it is commonly known that it is not commonly known...."
>>
>> Richard
>>
|