September 28, 2015 afternoon

Good afternoon. We survived that Monday somehow. I hope your day went well. 75 degrees and mostly cloudy although there are some pretty breaks in the clouds. There is a good chance for rain showers this evening but it will be hit and miss. Sunset at 6:42 PM and a full moon through the clouds rising about a half hour later.

Tonight’s bus is a International Senator Cutaway Bus. As traffic is completely stopped on the 787 expressway heading south of Downtown Albany, the driver is bypassing the cluster via McCarty Hill. I hate rush hour traffic on the bus. At least I’m not driving. Those cutaway buses hardly feel safe though. Oh well, I’ll make it home safely.

Researched installing a ammeter on the accessory battery. It’s a pretty easy install, just wire in a shunt on the ground wire, then run two wires from it to the ammeter in the cab plus a switched hot for the backlight. With the shunt, you only need small gauge wire. Ammeter shunts are such a simple device in principle but are cool that they work on voltage differential upon resistance.

I researched different ammeters but cane to the conclusion that an analog 60-0-60 one like was common on 1960s cars is best. The digital ones while much more accurate don’t really seem suitable for automobile purposes, as many can’t handle reverse currents – battery discharging – much less the dust and vibration of the automobile environment. Most people don’t use ammeters on cars these days but I would like to be able to monitor charge of the accessory battery without the guess work of a voltage meter alone.

For those of you not old enough to remember how a ammeter works on old cars, it gives a reading of amps currently flowing in or out of the battery. When the battery is discharged and the engine is on, the ammeter will show positive 15-30 amp as the battery charges. Once charged the ammeter will drop to almost zero and swing negative when the engine is off and there is a load on the battery.

It looks like the parts will set me back only about $30 and an hour of time to install. It will give me peace of mind knowing when I’m camping the battery is fully charged and also let me watch charging progress when the truck is idling.

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