Help with Valence U27 XP and Controller/Inverter setup for Popup

[brooke_heaton]

Hey folks, total nube here. I am working on outfitting my 2018 Aliner Ranger with a solar setup and large storage capacity for boondocking. I was able to grab two lightly used Valence U27 XPs (138AH) for a total of ~276AH in a 12V parallel setup. With this setup, I plan to use the Xantrex Freedom XC 2000 80Amp 120V inverter/controller which has a 2000W capacity and 4000W 2-second surge. It's generously large because my popup has a 120V AC unit and compressor fridge and I'd love to be able to go 5-7 days boondocking using solar (solar is in planning stages). I plan to use the Thunderstruck BMS for Valence U27s for HVC/LVC and HTC/LTC.

I have a few questions:

• Would the inverter/controller be able to detect high/low voltage and cutoff to protect the battery? And if so, is that even a concern since I'll have the Valence BMS?
• Should I use a battery protect on the 12V side? Or is that not compatible with the inverter?
• Is it necessary to add a shunt to this to monitor the batteries? Or is that overkill?
• What fuse should I be placing on the 12V side, which will have smaller loads but maybe up to 100amps?
• Is a surge protector necessary on the charger? I've seen some people mention surge protection and since I'll be at campsites/outdoors, maybe that's a good idea?

 

[snoobler]

• "Wide 10-18 VDC Input Range. Ensures inverter operation on high voltage alternators found on many new vehicle chassis" - implies it will cut off at 10V.
• Yes. No. Yes if you want to see the AGGREGATE battery information in one place. While you can connect to both, you have to mentally add the currents and you have two different SoC. A cheap battery monitor will give you a good one-stop place when you just want to glance at the overall battery status. Will recommends a "budget" one on his site for about $45 with a 350A shunt.
• Fuses should be 1.25X the expected peak current.
• IMHO, most of those recommendations come from surge protector manufacturers, but they're generally not a bad idea.

 

[Travis]

Is your u-Bms programmed properly to handle your number of batteries?

 

[brooke_heaton]

Is your u-Bms programmed properly to handle your number of batteries?

I have not yet set up the BMS, but I presume it would be able to handle 2 batteries. The manual outlines how to configure the BMS for the group of two. http://www.thunderstruck-ev.com/images/companies/1/VC1-Manual-20201014.pdf?1602695771461

I do not see a specific option to set the number of modules - the modules are automatically detected by the GMS.

The configuration options of the BMS include:

• “hvc” (high voltage cutoff) is the high voltage limit at which the BMS will open the HLS
• “lvc” (low voltage cutoff) is the low voltage limit at which the BMS will open the LLS
• “hvcc” (high voltage cutoff clear) is used to buffer cycling of the High limit switch. If a cell reaches HVC during charge, the BMS will shut off the charger, and the cell voltage drops slightly. The charger will turn back on below HVC, and the cycle repeats. Setting the HVCC below the HVC creates a delay to eliminate rapid cycling. The charger turns back on only after the highest cell voltage drops below HVCC.
• “lvcc” (low voltage cutoff clear) works the same as HVCC, but responds to the low end of the cell voltage range. This allows for turning the load back on only after the lowest cell voltage rises above LVCC.
• “tmax” maximum temperature in Centigrade for charge or discharge
• “tmin” minimum temperature in Centigrade for charge or discharge

 

[Travis]

I have not yet set up the BMS, but I presume it would be able to handle 2 batteries. The manual outlines how to configure the BMS for the group of two. http://www.thunderstruck-ev.com/images/companies/1/VC1-Manual-20201014.pdf?1602695771461

I do not see a specific option to set the number of modules - the modules are automatically detected by the GMS.

The configuration options of the BMS include:

• “hvc” (high voltage cutoff) is the high voltage limit at which the BMS will open the HLS
• “lvc” (low voltage cutoff) is the low voltage limit at which the BMS will open the LLS
• “hvcc” (high voltage cutoff clear) is used to buffer cycling of the High limit switch. If a cell reaches HVC during charge, the BMS will shut off the charger, and the cell voltage drops slightly. The charger will turn back on below HVC, and the cycle repeats. Setting the HVCC below the HVC creates a delay to eliminate rapid cycling. The charger turns back on only after the highest cell voltage drops below HVCC.
• “lvcc” (low voltage cutoff clear) works the same as HVCC, but responds to the low end of the cell voltage range. This allows for turning the load back on only after the lowest cell voltage rises above LVCC.
• “tmax” maximum temperature in Centigrade for charge or discharge
• “tmin” minimum temperature in Centigrade for charge or discharge

Only 2 batteries though you might consider having at least 4

 

[brooke_heaton]

Oh gosh no. This is for a small popup

Only 2 batteries though you might consider having at least 4

This is for a small popup camper. 4 would be major overkill for our needs and for the weight of the trailer.