When building my order last night I was told the battery monitor is not needed with lithium but then was trying to figure out how SOC is measured with the flat discharge voltage curve of lithium. Does the battery monitor measure AH?
Schneider Conext XW Pro 6848
- Thread starter ChrisG
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acdoctor
Solar Enthusiast
You input AH capacity, the shunt tracks in and out. Fully charged battery then syncing is done.
Wow. Wonder why they said not to use battery monitor (Nothern Arizona Wind/Solar). Guess they assumed I was going to by a Discovery battery or something.
Does the shunt come with the battery monitor or is it built into the inverter. If the former, where does the shunt get installed, in the load center?
I have 6 Trophy server rack batts and a Sol Ark 12K, no comms. I just manually look at the SOC indicator on the BMS displays periodically to see if they are all charging/discharging evenly. The Sol Ark % SOC estimation is good enough for me for general monitoring. My batts don't have proper communication with the Sol Ark yet. I have more battery capacity than I reasonably need, which I think is a good route for most people. I used to be the kind of person that obsessed over things not working perfectly, but as I've aged, good enough is good enough.
The shunt, and about a million little wires, was part of the Schneider battery monitor.
Koldsimer
Solar Addict
- Joined
- Dec 4, 2021
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I'm using the whiz-bang shunt in the midnite classic charge controller. I have the battery size set at 500ah and 99% efficiency. After many days of checking both batteries and the shunt, the classic always reports soc within 1% so i just depend on that. Even after multiple days of partial charges and discharges. My batteries are located under my house so checking soc on the actual modules is a pita. The charge controller is inside my house and it's easy to access.
As far as the sok and eg4, they are always within 1 or 2% of each other even after a deep discharge so they seem to work well together.
I use the Schneider battery monitor. AFAICT, it tracks SoC better than the Batrium bms does. It's integrated with the inverter and the AGS, but there is no ability to do things like taper charge in the mppt. I have 3 shunts and 4 devices (batrium, batt mon, and two midnite solar charge controllers with whbjrs) that track SoC so I monitor the differences. IIRC, some of the closed loop systems aren't fully integrated. They control the inverter, but do nothing with MPPTs. If you are buying batteries that advertise closed loop, make sure you read the fine print.
edit:
Here's my set points.
Confused on which Batrium hardware is needed for my setup
My Setup: I have 64 LiFeP04 cells coming my way. I'm very confused on which Batrium products I would need to support my setup. I think I'm confused because in their BMS kits, nowhere does it say what products I would need for a 16S4P. I do not have any existing Batrium products so I'm starting...
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Thanks for your reply. Guess I’ll get the battery monitor based on this info. Also thanks I you for your config parameters. Still undecided between LifePO4 vs FLA. Gets below freezing where these will be running and I think heating batteries is a waste vs getting FLA or AGMI use the Schneider battery monitor. AFAICT, it tracks SoC better than the Batrium bms does. It's integrated with the inverter and the AGS, but there is no ability to do things like taper charge in the mppt. I have 3 shunts and 4 devices (batrium, batt mon, and two midnite solar charge controllers with whbjrs) that track SoC so I monitor the differences. IIRC, some of the closed loop systems aren't fully integrated. They control the inverter, but do nothing with MPPTs. If you are buying batteries that advertise closed loop, make sure you read the fine print.
edit:
Here's my set points.
Confused on which Batrium hardware is needed for my setup
My Setup: I have 64 LiFeP04 cells coming my way. I'm very confused on which Batrium products I would need to support my setup. I think I'm confused because in their BMS kits, nowhere does it say what products I would need for a 16S4P. I do not have any existing Batrium products so I'm starting...
I used FLA for ~19 years and I'll never go back. If there is any way to work out the heat, I would do that. There are just so many more positives to having lithium like greater efficiency, smaller size/weight, higher depth of discharge limits, very little maintenance, no equalization, better lifetime/max cycles, etc, etc. Is this for a home/rv grid tied/off grid? It gets below freezing here to, but I have everything in a heated shed. You can't put the lithiums outdoors without heat, but you really don't want to put the FLA/AGMs outdoors without heat either. AGMs do have limits on low temps. I don't like batteries in the house, but if my choices were FLA/AGM outdoors in unheated box versus Lithium indoors, I would do lithium indoors. For lithium indoors, I would look at using sealed metal enclosures. Maybe using large contractor toolboxes with some mods.
acdoctor
Solar Enthusiast
Just my opinion FLA waist so much potential solar gain with their long Absorption cycle. I currently Grid sell to recapture that potential solar. As the amperage very slowly tapers off I sell more and more. Before while off grid at 2 P.M. I could produce 5700 watts but would only be producing 1500 maybe 2000 watts. Running minimum house hold and mini split A/C. My trailer I have LFP. They are more like filling a bucket with a garden hose. Just fill it up.
If I were offered half of what I have in my FLA I would gladly move to LFP.
FLA don’t like extreme temperatures either ideal is 77 deg f. All of my gear is in a heated and cooled shop. SCC will derate them selves if they get too hot. FLAs chemical reaction is faster in high temperature and causes shorter life. Cold FLAs charger slower and have less capacity, especially surge capacity.
Horsefly
Solar Wizard
I simply set the battery charge parameters and inverter LBCO as I would with Lead Acid, but using the numbers for LiFePO4. I've said before (in other threads) that I think the closed loop stuff is over-sold. I see a small benefit to lower the charging current near the end to allow balancing, but I've not really seen any problem with not having that. In the end, whether it is LiFePO4 or L-A you have numbers (bulk voltage, absorption voltage, float voltage, max absorption time, and tail current. You can just set these to work great for LiFePO4, or you can set them to work great for L-A.
Having said that, my 6 year old Schneider CSW4024 does have some quirks that make working with LiFePO4 a bit harder. For one, there seems to be a bug that won't let me set the charger to a bulk voltage of lower than 28.8V, which is significantly higher than the 28.0V I would prefer. Second, at least my version of the firmware doesn't let me set the LBCO higher than 24V (3V per cell). I would have preferred 24.8V (3.1V per cell), but I guess 24V will do.
Does anyone have a preferred place to buy Schneider equipment? AlltE store? Northern Arizone Wind and Solar? The PowerStore (about 20 miles from me with local pickup)? Unsure if these sellers provide any post purchase support. Any input would be much appreciated.
MichaelK
Solar Wizard
I bought my XW+ from these guys...
ressupply.com
RES Supply: Renewable Energy Systems for Less.
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Horsefly
Solar Wizard
+1 on NAWS. I've been very happy with components for two builds from them. I only had some issues on one of them, and they were quick to find answers.
All,
Thanks for your replies. NAWS has the best price and free shipping. At the cabin where this will be I have the well pump surge, ~9000W then levels to 1.3kw. Already moved important circuits to a critical load panel wired to main panel for time being. I have an emporia energy montior on my dedicated loads panel for the last couple months. Max concurrent watts I've ever seen was just over 4.2k (well pump and toaster was on at the same time with other loads). Average critical loads per day when we are present at the cabin is 12.5KWH, 4.5KWH when we are not present. I can't imagine needing two, but there will be plenty of room on the wall for it. Heat is baseboard 240v electric which is not in loads panel. Have a fireplace on main and wood stove on lower to reduce/eliminate baseboard heat and no need for AC here.
Thanks for your replies. NAWS has the best price and free shipping. At the cabin where this will be I have the well pump surge, ~9000W then levels to 1.3kw. Already moved important circuits to a critical load panel wired to main panel for time being. I have an emporia energy montior on my dedicated loads panel for the last couple months. Max concurrent watts I've ever seen was just over 4.2k (well pump and toaster was on at the same time with other loads). Average critical loads per day when we are present at the cabin is 12.5KWH, 4.5KWH when we are not present. I can't imagine needing two, but there will be plenty of room on the wall for it. Heat is baseboard 240v electric which is not in loads panel. Have a fireplace on main and wood stove on lower to reduce/eliminate baseboard heat and no need for AC here.
acdoctor
Solar Enthusiast
I purchased from Northern Arizone Wind and Solar. Great company and seemed to know their products. I didn’t test their technical expertise. I am a firm believer in RTFM.
IF you are purchasing panels be sure to get a extra or two. I didn’t have any damages but lots on here have. I am glad I got an extra in case of future problems. Mine are no longer available.
IF you are purchasing panels be sure to get a extra or two. I didn’t have any damages but lots on here have. I am glad I got an extra in case of future problems. Mine are no longer available.
Thanks. I’m a RTFM guy also. Want to know everything I can about the things I have. I’ll be getting the panels locally and that will be in a second phase. First phase is to get inverter, CC, battery, etc hooked up for power backup/grid failure before winter hits.
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