I am also wondering if you can leave the shunt out. The shunt is a drawback for me. I have the Victron 712 on one pack and a Bogart on the other. They are VERY good. I would never look on the Chargery for coulomb counting and I do not want the extra wiring for anything to interfere with my existing SOC system. If the Chargery can just take care of the cell level stuff I am good to go.
Chargery: AH measurements
- Thread starter Cal
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D
Deleted member 9967
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Yes you can leave the shunt out.
I use the juntek for a coulomb counter and it works great for me anyhow.
Well that moves the Chargery to the top of my list. Get around the amp limitations of the others.
Solarfun4jim
Solar seduced :-)
I thought i had read somewhere that without the shunt you no longer have over current protection...dont know if this is important to you or not?
D
Deleted member 9967
Guest
It is the relays that turn off the power NOT the shunt. So for protection from temps or voltages etc, you need a relay [or two].
Solarfun4jim
Solar seduced :-)
Any reason why the BMV712 shunt cant be installed directly before the negative battery terminal to give maximum SOC data and the chargery shunt in series next to give the cell level protections, but ignore the SOC data on it? That is my intention unless someone highlights a problem with this. Both units attached to do two seperate jobs.
Solarfun4jim
Solar seduced :-)
Without the shunt, what is measuring the current? If the shunt detects an over current condition on charge or discharge, then that activates the relay. It was my understanding that the BMS harness measures the voltages. I'm no expert...just picking up snippets as i go.
D
Deleted member 9967
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Not that i can think of.
I was considering that myself.
Get another juntek and have two way monitoring.
D
Deleted member 9967
Guest
Without a shunt I am not aware that you can measure the current.
I was just pointing out that the relays turn off the power not the shunt. The shunt MEASURES the amperage's. But it is the relays that do the actual turning off of the power.
grizzzman
Photon Vampire
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You're correct. The shunt is what the BMS uses for current control.
Well, the question is whether you would even need the Chargery shunt in that situation. You would still get cell voltage level, pack voltage level and temp protection without the chargery shunt. I don't want the Chargery shunt simply because for me it would serve no purpose the Victron does not do better and it is added connections and resistance in the circuit. (just more things to go wrong).
Solarfun4jim
Solar seduced :-)
Yes, but you would then need to link in your chargery onto the victron shunt for over current protection....imo. Easier for me just to run the two shunts, then no compatibility/calibration issues.
Bob B
Emperor Of Solar
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+1 .... A shunt is necessary for over current protection. I have a different monitor hooked to mine and have the Chargery connected to that shunt instead of using a Chargery shunt .... calibration isn't that tough if you have a way to set an accurate current.
The current measurement is also used to determine the mode the BMS is in .... but I don't know how that will affect things. It would always assume it was in storage mode.
Factory400
Solar Enthusiast
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I have the Chargery shunt as a measure of last resort. My primary source of energy monitoring is a Victron Smart Shunt which delivers a reasonable accuracy for my application. The Chargery accuracy is not useful in any way in my view. Looking forward to see what they deliver with the next generation.
So. Yes I have the Deltec 500 amp shunt on one setup and the Victron smart shunt on the other. I guess I could double up on the wires on the shunt but then I would need to recalibrate the Chargery (which may be no big deal) but I wonder if it would impact the accuracy of the Victron 712. What am I missing about the overcurrent protection? I have my lines fused and my Magnum charger0inverters also have overcurrent built in. Are we just after redundancy here? I have a handle on all my risks (I think) except for what is happening at cell level and temp cut off.
"It would always assume it was in storage mode." Oh. Well. If that is the case then the question would be if you could double up on a Victron smart shunt or whether you would be better off putting in two shunts.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
I cannot be certain absolutely about the Victron Shunt but with other shunts you can have one or more sense wires connected without a negative effect. In fact, the Midnite WizBangJr is similar to the Victron sensing on the shunt, it comes with standoffs for additional sense wires. Some Deltec shunts even come with extra screws for it. BTW, Midnite uses Deltec''s. The one catch is of course, you would have to calibrate the Chargery BMS to that shunt.
The Chargery has the an overcurrent setting, default is 50A I think, depends on model, if it senses over 50A it will trip the discharge circuit off, it can only use the shunt sensing for that.
The Chargery has the an overcurrent setting, default is 50A I think, depends on model, if it senses over 50A it will trip the discharge circuit off, it can only use the shunt sensing for that.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
Myself, I have one Chargery shunt per pack, the one shunt in the Midnite E-Panel with the WizbangJr and with the voltage calibration which was minimal, they generally all are pretty much in synch.
Got a chance to check Chargery new current measurement capabilities. The threshold for current measurement changed from 1A to 0.5A on a 300A shunt. Current resolution remains the same at 0.25 A / step. Graph shows solar charge for the day (130W panel). x-axis is time in minutes.
Thanks to Chargery for improving current measurement.
Thanks to Chargery for improving current measurement.
