Going to disagree. The FNDC only provides its voltage it doesn’t populate to the other devices.
You still have to set the inverter and CC separately, a poor design.
Depends on which mate you’ve got where the fndc voltage is located.
One reason I don’t like the CC voltage for aux control is that it gets off while higher charging due to VD. And with lithium which spend almost no time at lower absorb amps, it could effect the actual end volts.
And for whatever reason I have definitely had CC accuracy wander over time. IE the voltage calibration gets off for some reason.
Depending on the exact lithium, might not be a problem, some have wider upper limit than others.
Jay
On Jan 7, 2025, at 3:47 AM, Mac Lewis via RE-wrenches <[email protected]> wrote:
Hi Bill,
Do you have a flexnet in the system?
I assume that it wouldn't matter if the FM80 is calibrated but you will want the flexnet perfectly calibrated if you are using Lithium. It's a very annoying but worthwhile process. Don't drop the little nuts.
The flexnet acts as a master voltage device so the system will default its voltage readings to the flexnet voltmeter. I'm not sure if the aux function of the FM80 uses the FM80's voltage or the flexnet voltage to drive the relay, but this could explain the issue.
Good luck!
On Mon, Jan 6, 2025 at 10:51 PM Bill Battagin via RE-wrenches <[email protected]> wrote:
Hey Mac,
I've tried to calibrate the voltage displayed on the
Mate with the Fluke on the battery bus bars but it doesn't seem to
take after the adjustment in "calibrate". But The Flexmax 80 does
calibrate perfectly to the actual battery voltage and its in the
FM80 aux landing that I'm using for this go-around to shut down
the inverter to save the batteries.
'Manually' meaning.....?
Thanks,
Bill
Feather River Solar Electric
Bill Battagin, owner
4291 Nelson St. (Shipping)
5575 Genesee Rd. (USPS, UPS)
Taylorsville, CA 95983
530-284-7849, 258-1641(cell)
CA. C10 Lic # 874049
Solar Powered since 1982
Home of the Sunny Side Up
On 1/2/2025 5:53 PM, Mac Lewis via
RE-wrenches wrote:
Hi Bill,
Are all your voltages calibrated? Mate, Flexmax, FM80?
Where are you reading the voltages?
Does it work OK manually?
On Thu, Jan 2, 2025 at
12:08 PM Jay via RE-wrenches <[email protected]>
wrote:
Simpliphy has a very high voltage LVD.
And the older OB can’t be programmed to those
voltages
On Jan 2, 2025, at 10:04 AM,
Tyrone Houck via RE-wrenches <[email protected]>
wrote:
Forgive my ignorance but why won't the vfx lbco
work for lithium?
On Thu, Jan 2, 2025,
8:19 AM Bill Battagin via RE-wrenches <[email protected]>
wrote:
I
am trying to use the "low battery disconnect" in aux
mode in a newly
installed OB FM80 CC for Li battery low voltage
protection. I can't use
the 19 year old OB VFX inverters for obvious
reasons. The plan is to run
the 12 volt output from the aux output to a NC relay
to open it at 50
VDC of the bank of SimpliPhi 3.8M batteries. 50 VDC
is SimpliPhi's
recommendation for LVD. The "output" of the relay
would be connected to
the VFX's ON-OFF landings of that little green
terminal block in the AC
side of the inverter and just act as a simple switch
for the inverter to
turn it off to save the batteries.
I'm using one of my newer FM80's as a
test run and have
programmed the voltages in Low Battery Disconnect
mode and then put it
in auto mode. However, as the CC goes below the
voltage set point, the
AUX output does not turn on (time set for 5
seconds), as evidence in the
CC's home screen and by checking for 12V at the AUX
terminal block.
Any ideas of what I'm missing here to
make this work? I
know the other solution, thousands of $$ for new
inverters which would
be great but these folks have already invested quite
a chuck on array
replacement and charge controllers.
Thanks for any experience with this.
Bill
Feather River Solar Electric
Bill Battagin, owner
4291 Nelson St. (Shipping) 5575
Genesee Rd. (USPS, UPS)
Taylorsville, CA 95983
530-284-7849, 258-1641(cell)
CA. C10 Lic # 874049
Solar Powered since 1982
Home of the Sunny Side Up
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