I’d like to PAY someone to help me choose the settings on my Solar/Victron/Xantrex/and BMS


Solar Enthusiast
Jun 24, 2021
Hey everyone!!
EDIT: Yes you read that correctly. I’m willing to pay someone for some good advice helping me choose the settings. I can PayPal you money if you’re willing to help me answer the questions on my second post below.

I’m so excited. This is the end of the 5-month project!! Once this is finished I can finally move the boat out of Panama and head back home to Florida.
(*See next post down below for my questions about settings. I really need your help with them please.)

BACKGROUND: I’m finally reaching the end of my 5 month re-install of my LiFePo4 system. If you haven’t been following my other posts, I’ve completely replaced almost all the old cables and cheap breakers on my boat with large 4/0 cables and proper fuses. I took out all 48 of the (6 year old) damaged LiFePo4 cells and capacity tested each one. And on Tuesday, I’ll be reinstalling them. I’ve tried contacting Outback Solar, CALB battery company, Victron Smart Shunt, Overkill Solar BMS, and Xantrex Inverter and asked them what my settings should be… and all the companies were worthless and couldn’t give me an straight answer or wouldn't answer at all. So once again, I turn to you, the REAL experts for your advice.
Here is info about my system:

- BATTERY/CELLS: I’ll have 48 CALB brand 100Ah LiFePo4 cells configured for a 12v system, 3P 4S. They will form four large 300Ah batteries consisting of 12 cells each. Each of the four batteries will have its own Overkill Solar 120A BMS as well as QNBBM Lithium Battery Balancers to help equalize each of the four 3P cells of each battery. (See attached pic of configuration)

- SYSTEM CAPACITY: Total nominal Ah would be 1,200Ah, however after capacity testing each cell, the total ACTUAL capacity of the system is now only 1,044Ah

- CALB 100Ah LiFePo4 SPECS: (see attached pictures of spec sheet)
  • Nominal Caoacity: 100Ah (real capacity around 85Ah)
  • Nominal Voltage: 3.2v
  • Maximum Charging Current: 1C
  • Charging Upper Limit: 3.65v
  • Maximum Discharge: 2C
  • Discharging Cutoff: 2.5v
  • Recommended SOC: 10% - 90%
  • 8 Solar Panels 260w each (*one was replaced with 240w), 2,060w total
  • 3 Outback Solar Controllers:
  • Port #1: Flexmax 60A controlling two 260w panels
  • Port #2: Flexmax 80A controlling three 260w panels
  • Port #3: Flexmax 80A controlling two 260w and one 240w panels
  • Xantrex Freedom SW 3012 3,000w Inverter/Charger at 12v
  • Output Power: 3,000w @ 12v
  • Surge Rating: 6,000w @ 5 seconds
  • Peak Output current: 80A
  • Charger output Current: 150A @ 12v
  • Output efficiency: >85%
Overkill Solar 120A BMS
(Also known as Xiaoxiang BMS)

VICTRON 500A Smart Shunt


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Last edited:


Solar Enthusiast
Jun 24, 2021
This is the part I really need help with. I’ll go over each section and hopefully you guys can tell me the best settings to input based on the specs I gave above. I really appreciate it.

VICTRON 500A Smart Shunt:
(See pic for recent settings for my old lead acid batteries coming out.)

  1. Battery Capacity? I was told to input the actual tested 1,044Ah, not the nominal 1,200Ah
  2. Charged Voltage?
  3. Discharge Floor? 10%??
  4. Tail Current?
  5. Charged Detection Time? (In minutes)
  6. Peukert Exponent?
  7. Charge Efficiency Factor? (%)
  8. Current Threshold? (In Amps)
  9. Time-To-Go-Averaging Period? (In Minutes)
  10. Battery Starts Synchronized? (On or Off?)
  11. State Of Charge? (Manually set the Stage of Charge when I first install the batteries?)
  12. Synchronize SOC to 100%? (I’m guessing I can just press this instead of doing it manually when I first install the LiFePo4 back in?)
  13. Zero Current Calibrate? (I’m guessing no since the Victron app warns me against doing this.)
  14. Low SOC Alarm? (What % is good? I’m guessing 35% since 10% is considered empty?)
  15. Low Voltage Alarm? (In volts)
  16. High Voltage Alarm? (Currently disabled?)

(See pic for current settings)
  1. Absorb Voltage Volts?
  2. Absorb Voltage Time?
  3. Float Voltage?
  4. Rebulk Voltage?
  5. Current Limit? (I guessed and set this to 60A for the Flexmax 60A and I set it to 80A for the Flexmax 80A but I don’t know?)
  6. Absorb End Amps?

(See pic for current settings)
  1. MPPT Mode? (Currently on AUTO)
  2. U-Pick VOC? (It says 77% now?)
  3. Wake-up VOC Change?
  4. Wake-up VOC Change Time?
  5. Snooze Mode amps?
  6. MPP Range Minimum? (Currrently says “Half”?)
  7. MPP Range Maximum? (Currently set to 90%)

XANTREX Freedom SW 3012 Charger/Inverter:
  1. Battery Type: (currently set to “Custom” for LiFePo4)
  2. Battery Capacity: (I’m guessing I set this to my actual tested capacity of 1,044Ah and not the original nominal?)
  3. Max Charge Rate? (Currently set to 100%)
  4. Charge Cycle? (Currently set to 2-Stage No Float)
  5. Recharge Volts? (Currently set to 14.5v?)
  6. AC In Breaker? (Currently set to 25A and I don’t know why? I think the max is 30A?)
  7. Low Battery Cut Out? (Currently set to 10.5v)

*I won’t install this until Tuesday, and I’m not sure if I need to change the settings myself. So I already downloaded the App and opened the Demo to see what I need to config. See the pics attached.

OVERKILL App Settings:
  1. Charging Port On when Battery Off? (On or Off?)
  1. Number of Cells: (I’m guessing “12” since it’s a 3P 4S system)
Capacity Configuration:
  1. Total battery capacity in mAh? (I’m guessing 1,044,000.0 mAh since I have 1,044Ah?)
  2. Total Cycle Capacity in mAh?
  3. Cell Full Voltage in mV? (I don’t care about making these last, they are already 6 years old.)
  4. Cell minimal Voltage in mV?
  5. Cell Self-discharge Rate? (In %)
  6. Cell 80% Cap Voltage in mV?
  7. Cell 60% Cap Voltage in mV?
  8. Cell 40% Cap Voltage in mV?
  9. Cell 20% Cap Voltage in mV?
Balancer Configuration:
  1. Start Voltage in mV?
  2. Delta to Balance in mV?
  3. Balancer enabled? (On or Off? Keep in mind I’m also using the QNBBM Lithium Equalizers at the same time as this BMS. I was told it should work better that way.)
  4. Balance only when charging? (On or Off?)
Function Configuration:
  1. Switch? (On or Off?) *The fine print says “enable if your BMS has additional Switch to control the protection board”. I don’t have a switch that I know of?
  2. Load Detect? (On or Off?) *The fine print says “if on, you need to disconnect the load after short circuit to make output working again.
  3. LED Enabled? (On or Off?) *The fine print says “for BMS with LED soldered on only. Turns them on”. But I don’t think mine came with a BMS?
  4. LED Cap.? (On or Off?) *The fine print says “display SOC level on LED (5 Led - 100%)” but I’m not sure it came with an LED??
PIN / BMS Name:
  1. BMS Name? (Should I name each BMS so I can tell which battery I’m connecting to?)
  2. PIN Protect? (On or Off) I can set 2 different Pins it looked like… but should I?
  3. Barcode?
  1. Cell Over Voltage Trigger Value in mV?
  2. Cell Over Voltage Release Value in mV?
  3. Cell Over Voltage Delay in seconds?
  4. Cell Under Voltage Trigger Value in mV?
  5. Cell Under Voltage Release Value in mV?
  6. Cell Under Voltage Delay in seconds?
  7. Battery Over Voltage Trigger Value in mV?
  8. Battery Over Voltage Release Value in mV?
  9. Battery Over Voltage Delay in seconds?
  10. Battery Under Voltage Trigger Value in mV?
  11. Battery Under Voltage Release Value in mV?
  12. Battery Under Voltage Delay in seconds?
  13. Charge Over Current Trigger Value in mA?
  14. Charge Over Current Release Value in seconds?
  15. Charge Over Current Delay in seconds? (Is this needed a second time?)
  16. Discharge Over Current Trigger Value in mA?
  17. Discharge Over Current Release Value in seconds?
  18. Discharge Over Current Delay in seconds? (Is this needed a second time?)
  19. Charge Over Temp Trigger Value in C°?
  20. Charge Over Temp Release Value in C°?
  21. Charge Over Temp Delay in C°?? (Is this needed a second time?)
  22. Charge Under Temp Trigger Value in C°?
  23. Charge Under Temp Release Value in C°?
  24. Charge Under Temp Delay in C°?? (Is this needed a second time?)
  25. Discharge Over Temp Trigger Value in C°?
  26. Discharge Over Temp Release Value in C°?
  27. Discharge Over Temp Delay in C°?? (Is this needed a second time?)
  28. Discharge Under Temp Trigger Value in C°?
  29. Discharge Under Temp Release Value in C°?
  30. Discharge Under Temp Delay in C°?? (Is this needed a second time?)
NTC Settings: (checkboxes)
  1. NTC1? (On or Off?)
  2. NTC2? (On or Off?)
  3. NTC3? (On or Off?)
  4. NTC4? (On or Off?)
  5. NTC5? (On or Off?)
  6. NTC6? (On or Off?)
  7. NTC7? (On or Off?)
  8. NTC8? (On or Off?)


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New Member
Oct 17, 2021
I think it's important that you understand the charge curve of your battery banks. Once you fully understand that, then the answers you're looking for will be much more clear. You can use generic LifePo4 charge curves or measure it yourself. I would personally first start by measuring the IR (Internal Resistance) of each cell. Then group the cells that are similar in value together. From there, I'd do a full charge and then discharge to plot the charge curve of each cell bank bank and set the BMS accordingly for each 12V bank. All of this is to optimize amount of charge your can put in and take out of the battery bank without overcharging and over depleting. I personally would shoot for about 90% capacity for maximum cycles. Generally, you want your cells to cut off at 3V min and 3.55V max.

Good luck