Shunt Location - (should work but doesn't?)

[OR_Brewer]

so i picked up a battery monitor ( https://www.amazon.com/dp/B07FGFFHC6...ing=UTF8&psc=1 ) and thought i had the shunt wired properly. the problem was that even after running through the initial setup, the monitor never showed a reduction in AH or battery percentage.

the monitor DID show the amps and volts + and - though (e.g. showed amount of draw when there was one and amount of charge when generator was running).

i had the shunt mounted behind the electric panel. i had removed the battery neg (black line here on upper left of pic) and connected it to the b- terminal on the shunt. i then ran from the p- terminal on the shunt back to the same spot on the panel. (btw - the white line there goes to the converter).

is that not correct wiring? if im forced to connect at the front of the TT near the batteries, it's going to be a total pain running bthe line to the monitor. behind the panel would really be the most preferred option.

any help much appreciated. thanks!!

[Bama Rambler]

Unfortunately there are normally a lot of 'Negative' branches between the power center and the battery, so attaching the shunt where you show will never be accurate. You're going to have to mount the shunt at the battery and run the sense lint to the monitor.

[CHICKDOE]

do you know for absolute certainty that the black cable goes directly to the negative terminal of the battery and that there are no other cables connected to the battery negative terminal. my guess is the black cable goes to chassis ground and there are several cables leaving the battery negative terminal.

put the shunt right at the battery! remove all cables from the battery negative terminal and attach them to the non battery side of the shunt. then one and only one cable from the battery side of the shunt to the negative battery terminal. this forces all amperage to travel through the shunt before it is distributed.

[OR_Brewer]

Originally Posted by CHICKDOE

do you know for absolute certainty that the black cable goes directly to the negative terminal of the battery and that there are no other cables connected to the battery negative terminal. my guess is the black cable goes to chassis ground and there are several cables leaving the battery negative terminal.

so the black pictured there goes directly to TT chassis at the back of the rig. the neg cable off batt goes directly to chassis at the front of the rig.

still necessary to connect shunt up at battery as you described?

[jbflag21ds]

As stated above, there are plenty of loads that do not ground through that one cable. The shunt should be at the battery and all trailer side negatives connect to it and only the shunt connects to the battery.

[TitanMike]

Originally Posted by jbflag21ds

As stated above, there are plenty of loads that do not ground through that one cable. The shunt should be at the battery and all trailer side negatives connect to it and only the shunt connects to the battery.

It's not necessary to connect all grounds to the shunt as long as only ONE wire goes from battery negative post to chassis ground and the shunt is installed in that wire. Just so nothing goes in or out of the battery unless it passes through the ground wire with shunt installed.

Trying to connect all the devices that use the chassis ground directly to the shunt is a "Mission Impossible".

[jbflag21ds]

Originally Posted by TitanMike

It's not necessary to connect all grounds to the shunt as long as only ONE wire goes from battery negative post to chassis ground and the shunt is installed in that wire. Just so nothing goes in or out of the battery unless it passes through the ground wire with shunt installed.



Trying to connect all the devices that use the chassis ground directly to the shunt is a "Mission Impossible".

I reread what I posted and I can see that it could be unclear.

[mbbutler]

If you are connected to shore power, the charger would keep you from seeing any drop in AH or voltage.