Location For Voltmeter

tenbear wrote:

rjsurfer wrote:
Tenbear,

You said "Picking up a nearby 12v source may give you a reading higher than the battery voltage when charging the battery in boost mode. Or, maybe lower if you pick a line feeding a high current load, or if lights are on or off. "

Why would the voltage be higher? Just curious.

Thanks

Ron W.

The PD9200 and 4600 series converters put out 14.4v in boost mode. Depending on your battery bank and state of charge, the battery could be drawing 50 or even more Amps. Even a small resistance in the wire between the converter and the battery will result in a voltage drop, so the battery voltage will be lower than the converter voltage.

Many RVs have the fuse panel near the converter so the voltage in the 12v wiring will be the same as the converter voltage unless there is something drawing some current on that wire.

In my case. I have about 20' of #4 wire between the converter and the battery. At a current drain of 50A the 14.4v would be reduced to 14.15v at the battery due to that 20' of wire. There are also other voltage drops in the wiring, like circuit breakers, fuses and connectors.

All true, but my Trimetric and another voltmeter on a long wire to the batteries reads high. No effect from anything else drawing high amps.

I used the Trimetric's program for that to lower its reading to be the same as I get at the battery itself with a multimeter (which has a new battery so it is not reading high like they do with a low battery) (I did have to allow for the Trimetric reading to only one decimal place so it didn't round up unless at 0.5 or above.)