Shunt installation

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jstone
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Shunt installation

Post by jstone » Mon Aug 03, 2020 9:58 am

I have a FX Inverter, FM60, MATE3S, and Hub.

I currently do not have a shunt installed, but am about to install one, as I have some items connected directly to the battery that the CC/Inverter can not see.

How many shunts do I need, and where specifically should they be installed? I do not have FNDC, so if I understand correctly, the voltage drop will be sensed by the charge controller, correct?

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EA6LE-ONE
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MATE3s, 3 x Radian GS8048A,
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54 x PANASONIC VBHN325SA17 325W

System 2:
MATE3s, 2 x VFX3648,
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1 x FLEXnet DC, 2 x FLEXware ICS
21 x PANASONIC VBHN325SA17 325W
Location: Providenciales, Turks & Caicos Isl.

Re: Shunt installation

Post by EA6LE-ONE » Mon Aug 03, 2020 10:46 am

you need a shunt or more if you use a battery monitor like FNDC.

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Greg T Fordan
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Re: Shunt installation

Post by Greg T Fordan » Mon Aug 03, 2020 10:52 am

You need two shunts to capture the IN and OUT current on your system. One for the inverter, and the other to the charge controller. Just follow the diagram from the manual, where the shunts are connected on the negative side of the battery.
FNDC does not come with shunts, so make sure that the shunts you will acquire has the right millivolt to amps ratio. It should be 1mv = 10A. So you should get either the 500A:50mv shunt or the 100A:10mv shunts.
Greg T Fordan
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Outback Power Technologies

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EA6LE-ONE
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Posts: 282
Joined: Tue May 05, 2020 7:51 am
My RE system: System 1:
MATE3s, 3 x Radian GS8048A,
4 x FLEXmax 100, HUB10,
2 x EnergyCell 48V 2700RE,
1 x FLEXnet DC, 4 x FLEXware ICS Plus,
54 x PANASONIC VBHN325SA17 325W

System 2:
MATE3s, 2 x VFX3648,
2 x FLEXmax 100, HUB10
1 x EnergyCell 48V 2700RE,
1 x FLEXnet DC, 2 x FLEXware ICS
21 x PANASONIC VBHN325SA17 325W
Location: Providenciales, Turks & Caicos Isl.

Re: Shunt installation

Post by EA6LE-ONE » Mon Aug 03, 2020 11:17 am

Greg T Fordan wrote:
Mon Aug 03, 2020 10:52 am
You need two shunts to capture the IN and OUT current on your system. One for the inverter, and the other to the charge controller. Just follow the diagram from the manual, where the shunts are connected on the negative side of the battery.
FNDC does not come with shunts, so make sure that the shunts you will acquire has the right millivolt to amps ratio. It should be 1mv = 10A. So you should get either the 500A:50mv shunt or the 100A:10mv shunts.
There can be only one shunt installation as well. I find it much easier to know the status of my battery in OPTICSRE.

raysun
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Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: Shunt installation

Post by raysun » Mon Aug 03, 2020 11:20 am

jstone wrote:
Mon Aug 03, 2020 9:58 am
I have a FX Inverter, FM60, MATE3S, and Hub.

I currently do not have a shunt installed, but am about to install one, as I have some items connected directly to the battery that the CC/Inverter can not see.

How many shunts do I need, and where specifically should they be installed? I do not have FNDC, so if I understand correctly, the voltage drop will be sensed by the charge controller, correct?
Greg gave you the lowdown on proper shunt installation.

Two shunts will give fine grained monitoring of battery In and Out current.

If the additional loads attached to the battery are significant enough to track separately, the FNDC can accommodate a 3rd shunt and those loads can be placed on it.

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Greg T Fordan
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Re: Shunt installation

Post by Greg T Fordan » Mon Aug 03, 2020 11:44 am

EA6LE-ONE wrote:
Mon Aug 03, 2020 11:17 am
There can be only one shunt installation as well. I find it much easier to know the status of my battery in OPTICSRE.

Yes, we can do it like that, where in jstone's case, he will connect the inverter and charge controller in one shunt, one channel.
One thing with this set-up is there will be no separation of input current and output current. For example, the actual input current is 10A and the output current is 5A. What will show up in your FNDC device window is input current =5 and output current =0. Same goes with the Input kW and Output kW
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provo
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Hub 10
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Location: Sierra foothills

Re: Shunt installation

Post by provo » Mon Aug 03, 2020 11:45 am

jstone wrote:
Mon Aug 03, 2020 9:58 am
I have a FX Inverter, FM60, MATE3S, and Hub.

I currently do not have a shunt installed, but am about to install one, as I have some items connected directly to the battery that the CC/Inverter can not see.

How many shunts do I need, and where specifically should they be installed? I do not have FNDC, so if I understand correctly, the voltage drop will be sensed by the charge controller, correct?
If you don't have an FNDC (or some other battery monitor) why do you want shunts? Or is the FNDC on its way? If all you want is voltage info, you don't need shunts. OTOH, if you want current info, you need shunts AND a battery monitor like the FNDC.

Mike Curran
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My RE system: Outback - Garage roof:
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Shunt installation

Post by Mike Curran » Mon Aug 03, 2020 12:23 pm

I do not have FNDC, so if I understand correctly, the voltage drop will be sensed by the charge controller, correct?
No. As provo notes, you need an FNDC for accurate current measurements, your charge controller cannot use the shunt voltage drop.
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

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Greg T Fordan
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Re: Shunt installation

Post by Greg T Fordan » Mon Aug 03, 2020 12:45 pm

jstone wrote:
Mon Aug 03, 2020 9:58 am
xxx I currently do not have a shunt installed, but am about to install one, as I have some items connected directly to the battery that the CC/Inverter can not see.

How many shunts do I need, and where specifically should they be installed? I do not have FNDC, so if I understand correctly, the voltage drop will be sensed by the charge controller, correct?

I missed the highlighted information. So, I am modifying my initial recommendation. For optimum installation with FNDC and shunts, you need 3 -> one for inverter, one for CC, and one for the DC loads directly connected to the battery.

Thanks Raysun
Greg T Fordan
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Location: Victoria, Australia

Re: Shunt installation

Post by SandyP » Mon Aug 03, 2020 5:06 pm

jstone wrote:
Mon Aug 03, 2020 9:58 am
I have a FX Inverter, FM60, MATE3S, and Hub.

I currently do not have a shunt installed, but am about to install one, as I have some items connected directly to the battery that the CC/Inverter can not see.

How many shunts do I need, and where specifically should they be installed? I do not have FNDC, so if I understand correctly, the voltage drop will be sensed by the charge controller, correct?
Yes, the FM60 will "see" the battery voltage and if it falls due to your DC loads then will adjust its output to suit.

If you are looking to use a non outback battery monitor then you can get away with just one shunt BUT your DC loads will have to be connected "downstream" of the shunt (i.e. not on the "battery side" of the shunt).

jstone
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FM60-150
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FNDC

Re: Shunt installation

Post by jstone » Tue Aug 04, 2020 9:30 am

provo wrote:
Mon Aug 03, 2020 11:45 am
jstone wrote:
Mon Aug 03, 2020 9:58 am
I have a FX Inverter, FM60, MATE3S, and Hub.

I currently do not have a shunt installed, but am about to install one, as I have some items connected directly to the battery that the CC/Inverter can not see.

How many shunts do I need, and where specifically should they be installed? I do not have FNDC, so if I understand correctly, the voltage drop will be sensed by the charge controller, correct?
If you don't have an FNDC (or some other battery monitor) why do you want shunts? Or is the FNDC on its way? If all you want is voltage info, you don't need shunts. OTOH, if you want current info, you need shunts AND a battery monitor like the FNDC.
I see now. Thank you for that. I was not planning on an FDNC, but now that I have a shunt on the way I may just have to get one :grin: :grin: I thought the perceived voltage drop from the negative side would provide enough information to the CC to measure things like SOC.

That being said, for a small (6 battery, 3kw) system, is there really any real benefit to an FDNC, shunts, wiring, etc to just using voltage to monitor?

Thanks for clarifying that.

provo
Forum Czar
Posts: 531
Joined: Thu Jul 27, 2006 4:34 pm
My RE system: Sixteen Evergreen EC-120
(4 strings, total 1920W)
Eight Rolls S-550 (2 strings, total ~800Ah @ 24V)
One FM80
One VFXR3524A
Hub 10
Mate3s
FNDC and Trimetric
Location: Sierra foothills

Re: Shunt installation

Post by provo » Tue Aug 04, 2020 9:38 am

jstone wrote:
Tue Aug 04, 2020 9:30 am

for a small (6 battery, 3kw) system, is there really any real benefit to an FNDC, shunts, wiring, etc to just using voltage to monitor?
I don't think you've told us much about your batteries. What is the brand and model number? How are they wired together? The main benefit to knowing the SOC of your battery is so you can adjust your charge parameters to be sure they'll have a good long lifespan. If they were real cheap, it matters less...

raysun
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My RE system: Flexpower Two: (2) FXR3048A, (2) FM80, MATE3s, FlexNetDC
SimpliPhi 48-3.8 (6 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: Shunt installation

Post by raysun » Tue Aug 04, 2020 9:50 am

jstone wrote:
Tue Aug 04, 2020 9:30 am
provo wrote:
Mon Aug 03, 2020 11:45 am
jstone wrote:
Mon Aug 03, 2020 9:58 am
I have a FX Inverter, FM60, MATE3S, and Hub.

I currently do not have a shunt installed, but am about to install one, as I have some items connected directly to the battery that the CC/Inverter can not see.

How many shunts do I need, and where specifically should they be installed? I do not have FNDC, so if I understand correctly, the voltage drop will be sensed by the charge controller, correct?
If you don't have an FNDC (or some other battery monitor) why do you want shunts? Or is the FNDC on its way? If all you want is voltage info, you don't need shunts. OTOH, if you want current info, you need shunts AND a battery monitor like the FNDC.
I see now. Thank you for that. I was not planning on an FDNC, but now that I have a shunt on the way I may just have to get one :grin: :grin: I thought the perceived voltage drop from the negative side would provide enough information to the CC to measure things like SOC.

That being said, for a small (6 battery, 3kw) system, is there really any real benefit to an FDNC, shunts, wiring, etc to just using voltage to monitor?

Thanks for clarifying that.
For flying a small aircraft, is there any real benefit to having a fuel gauge or is the sound of the engine sputtering enough? 😉

Voltage as a measure of battery State of Charge (SoC) is difficult to correlate as voltage varies with load. The only time voltage and SoC correlate, as on most published charts, is when the battery is at rest (for at least 24 hours) and the battery temperature is at 75°F. This condition is not practical for most battery/inverter systems, so voltage as a metric is wildly imprecise.

A "coulomb counting" monitor like the FNDC or the Victron 7xx series, can give much more precise SoC data.

Since all the other components are Outback, adding the FNDC and two shunts will give a very nuanced look into charge flow, and is able to do so within the OpticsRE cloud application if Internet connectivity is available, or from the Mate's local web server if only LAN connectivity is at the site, and of course, on the Mate's display.

As for the FM60, it only knows about charge flow into the battery from it as the source. It would know (or care) nothing about charge being drawn from the battery, or of charge flow into the battery from any other source. It has no capability to read the voltage across the shunt.

jstone
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Posts: 35
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Re: Shunt installation

Post by jstone » Tue Aug 04, 2020 9:28 pm

provo wrote:
Tue Aug 04, 2020 9:38 am
jstone wrote:
Tue Aug 04, 2020 9:30 am

for a small (6 battery, 3kw) system, is there really any real benefit to an FNDC, shunts, wiring, etc to just using voltage to monitor?
I don't think you've told us much about your batteries. What is the brand and model number? How are they wired together? The main benefit to knowing the SOC of your battery is so you can adjust your charge parameters to be sure they'll have a good long lifespan. If they were real cheap, it matters less...
They are currently 4 renogy 12v 200ah batteries, 2 strings of 2. Not lithium price, but still $400 each. About to get to more, so I'll have $2400 worth of batteries and I'd like to take care of them.

jstone
Forum Whiz
Posts: 35
Joined: Sat Jul 25, 2020 10:36 am
My RE system: VFXR3524A
FM60-150
MATE3S
FNDC

Re: Shunt installation

Post by jstone » Tue Aug 04, 2020 9:30 pm

raysun wrote:
Tue Aug 04, 2020 9:50 am
jstone wrote:
Tue Aug 04, 2020 9:30 am
provo wrote:
Mon Aug 03, 2020 11:45 am


If you don't have an FNDC (or some other battery monitor) why do you want shunts? Or is the FNDC on its way? If all you want is voltage info, you don't need shunts. OTOH, if you want current info, you need shunts AND a battery monitor like the FNDC.
I see now. Thank you for that. I was not planning on an FDNC, but now that I have a shunt on the way I may just have to get one :grin: :grin: I thought the perceived voltage drop from the negative side would provide enough information to the CC to measure things like SOC.

That being said, for a small (6 battery, 3kw) system, is there really any real benefit to an FDNC, shunts, wiring, etc to just using voltage to monitor?

Thanks for clarifying that.
For flying a small aircraft, is there any real benefit to having a fuel gauge or is the sound of the engine sputtering enough? 😉

Voltage as a measure of battery State of Charge (SoC) is difficult to correlate as voltage varies with load. The only time voltage and SoC correlate, as on most published charts, is when the battery is at rest (for at least 24 hours) and the battery temperature is at 75°F. This condition is not practical for most battery/inverter systems, so voltage as a metric is wildly imprecise.

A "coulomb counting" monitor like the FNDC or the Victron 7xx series, can give much more precise SoC data.

Since all the other components are Outback, adding the FNDC and two shunts will give a very nuanced look into charge flow, and is able to do so within the OpticsRE cloud application if Internet connectivity is available, or from the Mate's local web server if only LAN connectivity is at the site, and of course, on the Mate's display.

As for the FM60, it only knows about charge flow into the battery from it as the source. It would know (or care) nothing about charge being drawn from the battery, or of charge flow into the battery from any other source. It has no capability to read the voltage across the shunt.
Awesome explanation. Thanks for that. I do have the mate3s via internet connection as I am gone often and I manage remotely. So with an FNDC and two shunts, (Please specify which..I have one outback 250 currently not installed) and you set various SOC options in OpticsRe, I'm assuming the FDNC now provides that data via the hub.

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EA6LE-ONE
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Posts: 282
Joined: Tue May 05, 2020 7:51 am
My RE system: System 1:
MATE3s, 3 x Radian GS8048A,
4 x FLEXmax 100, HUB10,
2 x EnergyCell 48V 2700RE,
1 x FLEXnet DC, 4 x FLEXware ICS Plus,
54 x PANASONIC VBHN325SA17 325W

System 2:
MATE3s, 2 x VFX3648,
2 x FLEXmax 100, HUB10
1 x EnergyCell 48V 2700RE,
1 x FLEXnet DC, 2 x FLEXware ICS
21 x PANASONIC VBHN325SA17 325W
Location: Providenciales, Turks & Caicos Isl.

Re: Shunt installation

Post by EA6LE-ONE » Wed Aug 05, 2020 3:28 am

jstone wrote:
Tue Aug 04, 2020 9:28 pm
provo wrote:
Tue Aug 04, 2020 9:38 am
jstone wrote:
Tue Aug 04, 2020 9:30 am

for a small (6 battery, 3kw) system, is there really any real benefit to an FNDC, shunts, wiring, etc to just using voltage to monitor?
I don't think you've told us much about your batteries. What is the brand and model number? How are they wired together? The main benefit to knowing the SOC of your battery is so you can adjust your charge parameters to be sure they'll have a good long lifespan. If they were real cheap, it matters less...
They are currently 4 renogy 12v 200ah batteries, 2 strings of 2. Not lithium price, but still $400 each. About to get to more, so I'll have $2400 worth of batteries and I'd like to take care of them.
You will have to stick with the ones you have now. Adding another string and a different generation than the ones you have is not advisable. better run this ones down and then buy the power you need in a single string.

Mike Curran
Forum Emperor
Posts: 1804
Joined: Sat Aug 28, 2004 6:28 pm
My RE system: Outback - Garage roof:
- 8 (2x4) Evergreen 180's into one FM80 (2007/2020 - replaced MX60)
- 6 (2×3) ALEO S79-300's into one FM80 (2017)
- 2 grid-tied GVFX3524's classic stacked for 120/240VAC (2007)
- 12 Surrette/Rolls 2V x 1766Ah (2007)
- Hub10.3, Mate3s, FNDC, RTS, OpticsRE. Tigo Energy ES maximizers on each PV module.

Westinghouse Solar - Barn roof: (2012)
- 30 (2x15) 235W panels with Enphase M215 microinverters, grid-tied

Outback Skybox - Barn roof: (2019)
- 14 Talesun 275W in series (DC array input to SB inverter/charger)
- 3 SimpliPhi 3.8 batteries, 48V, 225Ah total
- AC coupled input (manual switch during grid outage only) from 14 Talesun 275W,
Enphase M215 microinverters, normally direct grid tied

All self-designed and self-installed
Location: Chagrin Falls, Ohio

Re: Shunt installation

Post by Mike Curran » Fri Aug 07, 2020 6:55 pm

For flying a small aircraft, is there any real benefit to having a fuel gauge or is the sound of the engine sputtering enough? 
If you're flying an ultralight you can always glide in for a landing.
http://www.tigoenergy.com/site.php?95b2dca2-ca6c
https://enlighten.enphaseenergy.com/public/systems/Hctc107221

raysun
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Posts: 2993
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A, (2) FM80, MATE3s, FlexNetDC
SimpliPhi 48-3.8 (6 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: Shunt installation

Post by raysun » Fri Aug 07, 2020 7:32 pm

Mike Curran wrote:
Fri Aug 07, 2020 6:55 pm
For flying a small aircraft, is there any real benefit to having a fuel gauge or is the sound of the engine sputtering enough? 
If you're flying an ultralight you can always glide in for a landing.
Long as that pasture doesn't have the meanest bull in 3 counties, all good.

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