Dealing with Low Voltage Errors

Discussion about OutBack Inverters in Off Grid Applications

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rpbancroft
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Posts: 41
Joined: Mon Oct 29, 2018 10:41 am
My RE system: VFXR3524A inverter, FlexMax 80 charge controller, Mate3s

Re: Dealing with Low Voltage Errors

Post by rpbancroft »

I think I just connected some dots. Would this be a way to wire up 24-to-12v across two battery boxes/banks (not sure of the right term)?
  1. Wire both 12v, 4-battery banks to a battery bus bar (which will now output 24v)
  2. Use a 24v-to-12v DC-to-DC converter connected to that bus bar to output 12v
  3. Wire the 12v fuse box to the output lines of the converter
  4. I now have balanced 12v power available to my 12v fuse box from a 24v power bank
I assume I wouldn't have to change anything else, either - in the DC-to-AC wiring. I could just add additional ring terminals, alligator clips, or whatever to link the bus bar to both 12v banks.
raysun
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My RE system: Flexpower Two: (2) FXR3048A-01, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
Honda EU7000is gas fuel generator

Re: Dealing with Low Voltage Errors

Post by raysun »

rpbancroft wrote: Thu Jan 27, 2022 5:26 pm I think I just connected some dots. Would this be a way to wire up 24-to-12v across two battery boxes/banks (not sure of the right term)?
  1. Wire both 12v, 4-battery banks to a battery bus bar (which will now output 24v)
  2. Use a 24v-to-12v DC-to-DC converter connected to that bus bar to output 12v
  3. Wire the 12v fuse box to the output lines of the converter
  4. I now have balanced 12v power available to my 12v fuse box from a 24v power bank
I assume I wouldn't have to change anything else, either - in the DC-to-AC wiring. I could just add additional ring terminals, alligator clips, or whatever to link the bus bar to both 12v banks.
Yes, this is exactly correct.

As a side note, there are two battery boxes, but in fact only one battery. Its output voltage = 24V. That you can access the individual blocks and measure 12V at certain points in the connection scheme is only incidental, and, other than for maintenance should not be connected to. 24V is the nominal battery voltage.
rpbancroft
Forum Whiz
Posts: 41
Joined: Mon Oct 29, 2018 10:41 am
My RE system: VFXR3524A inverter, FlexMax 80 charge controller, Mate3s

Re: Dealing with Low Voltage Errors

Post by rpbancroft »

Thank you for the clarification! I've been struggling to figure out how to think about it. I figured it's all one battery, but being able to measure less than 24V, and having to figure out how to wire these low-voltage lines to make things work sensibly, was confusing me. That does make more sense.
raysun
Forum Emperor
Posts: 7787
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A-01, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
Honda EU7000is gas fuel generator

Re: Dealing with Low Voltage Errors

Post by raysun »

A different question regarding the 12V pump and UV filter: They are being powered via 12V-DC. Can they accept 12V-AC?
rpbancroft
Forum Whiz
Posts: 41
Joined: Mon Oct 29, 2018 10:41 am
My RE system: VFXR3524A inverter, FlexMax 80 charge controller, Mate3s

Re: Dealing with Low Voltage Errors

Post by rpbancroft »

raysun wrote: Thu Jan 27, 2022 5:43 pm A different question regarding the 12V pump and UV filter: They are being powered via 12V-DC. Can they accept 12V-AC?
Huh, an interesting question. I didn't even know that was a thing? I've been told by Luminor that the pump cannot use AC (unless you get their AC model, but I've been running it with a DC-to-AC converter without issue, but want to go back to DC because that's what it's rated for and supposedly happiest with). Would it say in the spec sheets if they support that?
raysun
Forum Emperor
Posts: 7787
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A-01, (2) FM80, MATE3s, FlexNetDC
6 SimpliPhi 3.8-48 (48v @ 75AH. 450AH total)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
Honda EU7000is gas fuel generator

Re: Dealing with Low Voltage Errors

Post by raysun »

rpbancroft wrote: Thu Jan 27, 2022 5:54 pm
raysun wrote: Thu Jan 27, 2022 5:43 pm A different question regarding the 12V pump and UV filter: They are being powered via 12V-DC. Can they accept 12V-AC?
Huh, an interesting question. I didn't even know that was a thing? I've been told by Luminor that the pump cannot use AC (unless you get their AC model, but I've been running it with a DC-to-AC converter without issue, but want to go back to DC because that's what it's rated for and supposedly happiest with). Would it say in the spec sheets if they support that?
It should say so. Note, not 120VAC, but 12VAC.
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