Hi!
Got a problem with my 712. SImple setup - one 75AH battery and a 712. Basic default setup.
When I have connected my inverter readings were weird (35A drawing for small load) then I connected 28W 12V bulb - reading was 105W 8.4A - again waaay too much.
Is this faulty unit? Or I'm doing something wrong.
could you possibly have connected something to the small screws on the sensor board? (board on the Shunt)
Hi lygi, what you describe can definitely cause the error, because you increase the shunts resistance to the sensor board with this, leading to a higher voltage drop and as a result, the values will be too high.
Hope re wiring will fix your issue.
Regards,
Markus
What I can add, charging is also weird. I'm using 7 stage 20A charger, and charging current on 712 looks like attached. 
Hi lygi, maybe your shunt setting is not correct. Can you make an additional picture of your shunt settings please.
Do you use the shunt the unit was shipped with?
Hi Markus,
Item is brand new, shunt is the original one, and I've checked settings for it and they match. All other settings are as they were original - just AH been adjusted
hm. Are the wrong values linear or not?
so voltage is more or less OK, current is somewhere between x2 to x3 too high
1.5 A shows as 5A, 20A charging shows as 40A
I will try to load it with a car bulb and compare readings with Digital multimeter.
Ok.
I would double check the shunt settings. If it's not too much effort, make a Picture though and post it here.
good point Boekel! Because original shunt screws are huuuge and my terminals were just to small to use the shunt screws, I put my ring terminals between plate and shunt - I didn't expect this can make any difference BUT - this can be a case! Let me redo this part of wiring and will post the results
Now can't wait to get back home an rewire it haha ;) ANyway - will come back tomorrow and will let you know.
I had this problem for exactly the same reason: I attached my BMS lead directly to the screw holding the shunt circuit board to the shunt. This caused my 45 Amp charge current to be measured as 70+ Amps. Doesn't seem like it would make that much of a difference, but it does.
I originally wired the BMS directly to the screw because my battery cable lugs were all too small to fit to the shunt bolts. Ended up drilling the lugs to fit the shunt. Very happy customer now!
PS: might be a good idea to mention in the owners manual of BMS systems that wiring to the screws of the shunt is a no-go.
Thank you for hosting this community forum, and for producing these products.
Hi @dkovacevic
I think it's actually written on the pcb, to not connect anything else to it...
