battery cutoff set points
Shawn-H
Solar Expert Posts: 107 ✭✭
I'm trying not to use more than 50% DOD on my batteries. I have people in my home that are not aware of how solar works. so I do not want to lower the threshold below 11.8. The problem is is as we know while there is a load on the system the voltage will read lower than it really is so on a cloudy day if my well pump kicks on the whole system will shut down. so does anybody have any suggestions of a good place to set it so this does not happen? so I don't get called home from work again because they have no power. I have it set at 11.8 right now I'm using 2 Outback power VFX3524 in the fw-500.
100% Off-grid in the White Mountains of Arizona. 36 Kyocera 265w mounted on four DPW 9 module pole top mounts, midnite solar combiners, breakers, & lightning arresters, 1 midnight solar classic 150, & 3 classic 150 lights, 3 x 1574 AH GB Industries forklift batteries total of 4722 AH @24v. Feeding a Outback power systems FW500 with 2 x VFX 3624, with the x240. 2 Honda EU3000is gensets with the 240 combiner and control box running LP, and 1 Honda EU2000is Gas.
System #2 is a off grid water system @ 1590w (6 Kyocera 265's) on a 6 module DPW top of pole mount. Feeding a Granfas deep well pump and pump controller at 580 feet. 2 x 2800 gallon above ground poly storage tanks, and 1 x 1200 gallon underground cistern and a Granfas 24v booster pump feeding a 90 gallon carbon fiber pressure tank.
Vag woodstove for heat.
Follow our journey at
https://www.facebook.com/ShawnpHarvey
System #2 is a off grid water system @ 1590w (6 Kyocera 265's) on a 6 module DPW top of pole mount. Feeding a Granfas deep well pump and pump controller at 580 feet. 2 x 2800 gallon above ground poly storage tanks, and 1 x 1200 gallon underground cistern and a Granfas 24v booster pump feeding a 90 gallon carbon fiber pressure tank.
Vag woodstove for heat.
Follow our journey at
https://www.facebook.com/ShawnpHarvey
Comments
-
You could try ~11.5 volts for the cutoff... Use a Hydrometer to estimate the battery bank state of charge.
You could also try a battery monitor (Trimetric or Victron are a good point to start looking) -- They will give readings in percent, and with the Victron, you could set an external alarm (flashing light, etc.) when the batteries are getting low--But not turn anything off.
Tell them something like:
>75% SOC, all is fine
75% to 50% start cutting back on loads, especially if cloudy/winter day
<50%, start genset. Run genset until >80% state of charge.
<45% call you.
There are some voltage only Battery Monitors--I am not sure how well they work (others here may have some information):
Midnite Battery Monitor
SmartGuage
Those may be "good enough" for the family.
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
You could try ~11.5 volts for the cutoff... Use a Hydrometer to estimate the battery bank state of charge.
You could also try a battery monitor (Trimetric or Victron are a good point to start looking) -- They will give readings in percent, and with the Victron, you could set an external alarm (flashing light, etc.) when the batteries are getting low--But not turn anything off.
Tell them something like:
>75% SOC, all is fine
75% to 50% start cutting back on loads, especially if cloudy/winter day
<50%, start genset. Run genset until >80% state of charge.
<45% call you.
There are some voltage only Battery Monitors--I am not sure how well they work (others here may have some information):
Midnite Battery Monitor
SmartGuage
Those may be "good enough" for the family.
-Bill100% Off-grid in the White Mountains of Arizona. 36 Kyocera 265w mounted on four DPW 9 module pole top mounts, midnite solar combiners, breakers, & lightning arresters, 1 midnight solar classic 150, & 3 classic 150 lights, 3 x 1574 AH GB Industries forklift batteries total of 4722 AH @24v. Feeding a Outback power systems FW500 with 2 x VFX 3624, with the x240. 2 Honda EU3000is gensets with the 240 combiner and control box running LP, and 1 Honda EU2000is Gas.
System #2 is a off grid water system @ 1590w (6 Kyocera 265's) on a 6 module DPW top of pole mount. Feeding a Granfas deep well pump and pump controller at 580 feet. 2 x 2800 gallon above ground poly storage tanks, and 1 x 1200 gallon underground cistern and a Granfas 24v booster pump feeding a 90 gallon carbon fiber pressure tank.
Vag woodstove for heat.
Follow our journey at
https://www.facebook.com/ShawnpHarvey -
Make sure to double check everything (i.e., use a hydrometer once in a while to validate the SOC readings). Battery Monitors can "drift" at times/under some conditions.
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
A ew hrs in the dark may sharpen their observational skills, as to using too much power in the first place...:roll:
KID #51B 4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
West Chilcotin, BC, Canada -
westbranch wrote: »A ew hrs in the dark may sharpen their observational skills, as to using too much power in the first place...:roll:
yes sir. I tried that but unfortunately all it did was make me sleep on the couch the wife didn't appreciate it much especially when she found out all she had to do was start the generator lol100% Off-grid in the White Mountains of Arizona. 36 Kyocera 265w mounted on four DPW 9 module pole top mounts, midnite solar combiners, breakers, & lightning arresters, 1 midnight solar classic 150, & 3 classic 150 lights, 3 x 1574 AH GB Industries forklift batteries total of 4722 AH @24v. Feeding a Outback power systems FW500 with 2 x VFX 3624, with the x240. 2 Honda EU3000is gensets with the 240 combiner and control box running LP, and 1 Honda EU2000is Gas.
System #2 is a off grid water system @ 1590w (6 Kyocera 265's) on a 6 module DPW top of pole mount. Feeding a Granfas deep well pump and pump controller at 580 feet. 2 x 2800 gallon above ground poly storage tanks, and 1 x 1200 gallon underground cistern and a Granfas 24v booster pump feeding a 90 gallon carbon fiber pressure tank.
Vag woodstove for heat.
Follow our journey at
https://www.facebook.com/ShawnpHarvey -
Make sure to double check everything (i.e., use a hydrometer once in a while to validate the SOC readings). Battery Monitors can "drift" at times/under some conditions.
-Bill
very good advice thank you.100% Off-grid in the White Mountains of Arizona. 36 Kyocera 265w mounted on four DPW 9 module pole top mounts, midnite solar combiners, breakers, & lightning arresters, 1 midnight solar classic 150, & 3 classic 150 lights, 3 x 1574 AH GB Industries forklift batteries total of 4722 AH @24v. Feeding a Outback power systems FW500 with 2 x VFX 3624, with the x240. 2 Honda EU3000is gensets with the 240 combiner and control box running LP, and 1 Honda EU2000is Gas.
System #2 is a off grid water system @ 1590w (6 Kyocera 265's) on a 6 module DPW top of pole mount. Feeding a Granfas deep well pump and pump controller at 580 feet. 2 x 2800 gallon above ground poly storage tanks, and 1 x 1200 gallon underground cistern and a Granfas 24v booster pump feeding a 90 gallon carbon fiber pressure tank.
Vag woodstove for heat.
Follow our journey at
https://www.facebook.com/ShawnpHarvey
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