I'm having some charging issues and was wondering if the scanmaster readout for BAT was equal to that which would be measured using a voltmeter at the battery?

My alternator runnin below the halfway mark and the scanmaster indicates that the BAT values fall from about 13.5 at startup to 12.3 at idle over a 5 minute period.

 

I've noticed some discrepancies on the "volt" reading from the ScanMaster. It seems to read lower than the dash gauge, and it also seems to read lower than the "volt" reading from my MoTeC engine management computer. Appears each one is reading voltage at a different point in the system.

In any case, the difference is simply that the ScanMaster just reads lower than the other two by about 0.5V-1.0V. If the system voltage falls off, it falls on the SM, the gauge and in the MoTeC.

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Fred
94 Formula A3+1: 381/TH400+OD/N2O

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11.513@115.59 on motor; 11.162@127.67, 1.643 60' on a 125-shot. Going with a 275-shot this year

 

The Scanmaster is probably reporting what the PCM is telling it since voltage is one of the parameters in the data stream.
The voltage to the PCM may be lower because of a drop going through the ignition switch and wiring harness.