Date:         Sat, 30 Aug 2014 09:49:24 -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: Fridge on 12V
Comments: To: Alistair Bell <albell@shaw.ca>
In-Reply-To:  <AAC86A6A-9B61-419A-8A1A-84E210F55A7E@shaw.ca>
Content-Type: text/plain; charset=windows-1252; format=flowed

No reason to measure amps through the cooler because amps to the socket
= amps going through the cooler because amps in always equal amps out.

But heating at the socket indicates that some voltage is being lost
there because heat comes from power (watts) and power = volts x amps.

Rather than measure amps going through the refrigerator, more to the
point is volts lost across the socket/plug connection. If there are 2
volts (say) dropped across the connection, then the cooler has 2 fewer
volts to work with, thus less power, thus less heat, thus less cooling.

12 volts @ 9 amps = 108W, but 10 volts @ 9 amps = 90W. The other 18
watts are being dissipated at the socket, instead of in the cooler's
element.

That said, there's also no need for me to measure this stuff because the
hot plug is reason enough on its own to sort out, and it indicates that
it is stealing power from the element. I may switch over to a burlier
connector. A little Anderson Powerpole, mebbe.

--
Jack "Rocket j Squirrel" Elliott
1984 Westfalia, auto trans,
Bend, Ore.

On 08/30/2014 09:27 AM, Alistair Bell wrote:
> You are drawing 9 Amps from the battery yes, but if the lighter socket is getting hot that would indicate resistance in the connection and some portion of the current is being lost, converted to heat, before it gets to the cooler. Can you measure amps at the cooler?
>
> Right?
>
> Alistair
>
>
>
>
>> On Aug 30, 2014, at 9:09 AM, Rocket J Squirrel <camping.elliott@GMAIL.COM> wrote:
>>
>> This came up about a week ago. In theory, the 120V and 12V elements
>> should While driving I had it hooked to the house battery,
>> and I can tell that it was drawing plenty power because the cigar
>> lighter plug got real warm -- hot almost. Shouldn't get that hot, I'm
>> going to look into the thing to see if I can sort it out. The house
>> battery ammeter showed about 9A of constant current draw, indicating a
>> solid current path.
>>
>>>