Quote:
Originally Posted by longshot270
Jack, I bet that the numbers your getting have something to do with the Voltage=Amps/Resistance formula. If the battery tender uses clamps to connect to the battery then it will read more resistance than the vehicle(because the vehicle has been bolted in since day 1). More resistance is going to make the voltage look lower without any higher amps. Could be wrong but it sounded good when it ran through my head.  |
Longshot - we MAY be talking about two different things. The voltage and amperage numbers I quoted in the other post are with a good digital multimeter. The parasitic draw in my truck is definitely 0.05 amps (50 ma) after the truck has been sitting in a "quiet" state - doors closed, everything shutdown for at least one hour. To this list of what Lars posted for current draw, I also have memory for the pedals and seats and memory for the climate control temperature. The King Ranch also has the door open keypad that has to be alive to accept key input and all our trucks probably have a powered receiver to accept signals from the key fob for remote door unlock.
In this post, the 13.9-14.1 volts are being displayed on the Gryphon with the engine running and this seems a pretty normal regulated charging voltage from the alternator.
What I found puzzling, is the state of the battery after driving. I expected it to be at or near a full charge state. But, I think I just figured out why that may not be so. My headlights have the "auto-on" feature, so when I drive into the garage, they come on. They stay on for about 20 seconds after I shutdown too, as do the interior lights after I get out an close the doors. There seems to be some other, less obvious circuits that are alive too, for about 5 minutes, until the battery saver relay opens. This puts a fairly heavy draw on the battery.
By the time I get my battery tender hooked up, it takes about 6-8 hours to reach the fully charged state (since it uses a very low charging current to keep from "boiling" the battery - about 0.2 Amps) when the battery is above an 80% charge state. If I simply unplug the battery tender and then plug it back in again, its operation indicates a full charge within a very short time, since there was no big drain while it was disconnected.
The 0.05 Amp draw from the Gryphon (when it's plugged in) was confirmed with Bill. I know I have a total parasitic draw of 0.1 amps when the Gryphon is installed.
Finally, as Lars said, the Battery Tender comes with a "permanent" plug in connection you can attach to the screw terminals of the battery posts. This makes it simple to use.
- Jack