Hi, I have a new battery bank and want to put my smartshunt onto this, but it’s reading completely different current from the actual current being used.
I currently have it hooked up to a Renogy smart battery with inbuilt bluetooth / shunt, I was using this so I could check the Smartshunt against the inbuilt shunt before I move it the new 400A battery which does not have bluetooth so I have no way of confirming what it’s reading is correct, as you can see below the differences are huge.
Any ideas what settings I have wrong / not configured correctly, I did an initial 100% SOC sync.
Actual current being used from internal battery’ BMS it’s showing 141A load.
All loads are connected to a 320A buss bar with a single connection from the buss bar to the output of the shunt via copper cables and a single connection via copper cables from the shunt to the battery.
Normally one would check current with a clamp meter.
If you have a good multimeter, you could measure the voltage drop across the shunt.
For a 500a SmartShunt, you will get a voltage difference of 50mV @ 500a.
Or 10 mV @ 100A.
Stab the probe points into each brass end of the shunt.
I discovered the problem, it’s something to do with the Aluminium buss bars, these are 40mm x 10mm T6061.
When all the connections are made through the buss bars I get the error.
If I remove the buss bar from the equation and connect either directly to the shunt or to the copper wiring connected to the shunt, everything is pretty much equal.
There is obviously something going on when using the Aluminium buss bar that’s interfering with the results.
Even if I just leave the shunt connected to the buss bar, then connect a static charge such as 40A input directly to the shunt, the meter shows 39.5A coming out of the charger and the Victron shunt shows 8.7A coming in.
if I leave the wiring connected to the shunt, but disconnect the other end from the buss bar the victron will show 39.5A coming in.
I measured the resistance of the buss bar and it’s 0.41 ohm so basically dead short.
I can’t explain it but the victron shunt doesn’t like being connected to the buss bar.
I’m wondering if the Aluminium bar was copper or nickel plated if that would help ?
I might give it a try.
It appears it is done by smoke and mirrors, here are some pics of the insides of the battery.
I have been using this single 200A for about 8 months and it’s always been accurate so have no reason to doubt it accuracy.
They are not directly connected, there are short copper cables joining the shunt to the buss bar.
Here is a pic of the buss bars I made last week.
I’m interested to work out why the Victron does not like them, I might make some new ones from Copper or Brass and see how they go, I only used the Aluminium as that’s all I had lying around.
All I did was swap out the two Aluminium bars for two smaller off-the-shelf nickel plated cheapy things I had in a box, retested and it was all ok, so re installed one Aluminium buss to the positive and it was still ok, then swapped the negative one and it was all working as expected.
I really wish I could have found out what caused it as the Aluminium buss bars should not have had anything to do with it.
