XW 6048 - Enhanced Interactive Mode. Where do I select EIM?

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  • DustyDusty Solar Expert Posts: 271 ✭✭✭
    Re: XW 6048 - Enhanced Interactive Mode. Where do I select EIM?
    Joe_B wrote: »
    In case it has not been mentioned previously, your battery bank capacity is woefully undersized for your inverter. Xantrex recommends at least 100 AH per KW. You should have at least 400AH preferably closer to 800 AH. You should also monitor the charge rate that your panels charge the batteries at. I know AGM's can take a higher charge rate than my FLA's but for some reason if the grid went down when it was sunny out, you could potentially dump all of your solar harvest into your bank and cook things.


    I'll keep a close eye on it. With my current setup, on a sunny day I'm seeing about 1500-1900 watts coming from the PV array into the 6048 to support loads and sell to the grid. I originally had sell amps set to 5 to ensure I didn't draw too much from the batteries, and I've been increasing it ever so slightly (it's now at 12 amps) to see if I start to get error messages from the 6048. So far, I haven't received any faults or warnings on the SCP. On average, my home is using about 250-400 watts during the day--aside from the geothermal heat pump which is not tied to the 6048 subpanel.

    I could reduce the percentage charge on the SCC and 6048 from 100 so some other value, but I'm not sure what to reduce it to?:confused:
    XW6048, 3.4KW PV, Grid-Tied, always tweaking.
  • Joe_BJoe_B Solar Expert Posts: 318 ✭✭✭✭✭✭
    Re: XW 6048 - Enhanced Interactive Mode. Where do I select EIM?

    The problem will occur when the grid fails. Your XW will go into invert mode and not be able to sell to the grid. The only load on your system will be the local loads (250-400 watts) therefore, the rest COULD be cranked into your battery. The fact that you are running in EIM will keep the battery topped off so they wont be too depleted and will probably be OK but consider this: Its cloudy and your grid goes down, the loads will be supported by the battery and the SOC will drop. Now the sun comes out from behind the clouds, your SCC is set to 100% and you start to harvest 2KW of solar. Where does it go? the SCC will go to bulk mode and crank 40 amps into your battery. That is a huge charge rate and I dont think your battery will like it. Also consider this scenario, It's cloudy out and the grid goes down. Your loads will be supported by the battery (250-400 watts). Factor in the 80 sumodd watts for the inverter and you could be drawing 500 watts from your bank. Your bank will be bottomed out pretty quickly, then your LBCO will kick in and your inverter will shut down. Another issue, You have a day where the sun is out and there are big puffy white clouds passing by. Your solar is on and off. When its off, the XW will pull power out of your bank, when its on, your SCC will pump current back in to the battery. The ripple current will be quite high, not a good thing for the health of your battery. The XW REQUIRES a minimum of 100 AH per KW so you really need to increasy your battery capacity to at least 400 AH to keep things stable. Just offering advice based on my practical experience not bitching at you. I was helping a guy on this forum about a year ago who was doing the same thing as you. He had about 100 AH hooked up to his XW4024. He very quickly destroyed his battery bank in less than a year of use. You should expect that in a properly designed system to get 7 -10 years of battey life but if you beat on the battery, they can die faster than you can believe. Just saying....
  • DustyDusty Solar Expert Posts: 271 ✭✭✭
    Re: XW 6048 - Enhanced Interactive Mode. Where do I select EIM?

    Joe,

    I appreciate all of your advice and don't think you are being too critical. I, like others, saw the "100 ah" requirement in the 6048 manual--not knowing it should have been 100ah per 1KW of PV.

    Since my corrected PV (2.6kw * .77 = 2kw) is only 2KW, wouldn't 200ah be sufficient, or are you figuring that my 2KW of PV power could keep 400ah of battery capacity properly charged-- and therefore that's the ideal bank capacity?

    Because my attached garage is the location of my battery bank, it has to remain AGM, and space is limited, so I have to be sure I could properly store 400ah of capacity. Thanks again!

    -Dusty
    Joe_B wrote: »
    The problem will occur when the grid fails. Your XW will go into invert mode and not be able to sell to the grid. The only load on your system will be the local loads (250-400 watts) therefore, the rest COULD be cranked into your battery. The fact that you are running in EIM will keep the battery topped off so they wont be too depleted and will probably be OK but consider this: Its cloudy and your grid goes down, the loads will be supported by the battery and the SOC will drop. Now the sun comes out from behind the clouds, your SCC is set to 100% and you start to harvest 2KW of solar. Where does it go? the SCC will go to bulk mode and crank 40 amps into your battery. That is a huge charge rate and I dont think your battery will like it. Also consider this scenario, It's cloudy out and the grid goes down. Your loads will be supported by the battery (250-400 watts). Factor in the 80 sumodd watts for the inverter and you could be drawing 500 watts from your bank. Your bank will be bottomed out pretty quickly, then your LBCO will kick in and your inverter will shut down. Another issue, You have a day where the sun is out and there are big puffy white clouds passing by. Your solar is on and off. When its off, the XW will pull power out of your bank, when its on, your SCC will pump current back in to the battery. The ripple current will be quite high, not a good thing for the health of your battery. The XW REQUIRES a minimum of 100 AH per KW so you really need to increasy your battery capacity to at least 400 AH to keep things stable. Just offering advice based on my practical experience not bitching at you. I was helping a guy on this forum about a year ago who was doing the same thing as you. He had about 100 AH hooked up to his XW4024. He very quickly destroyed his battery bank in less than a year of use. You should expect that in a properly designed system to get 7 -10 years of battey life but if you beat on the battery, they can die faster than you can believe. Just saying....
    XW6048, 3.4KW PV, Grid-Tied, always tweaking.
  • Joe_BJoe_B Solar Expert Posts: 318 ✭✭✭✭✭✭
    Re: XW 6048 - Enhanced Interactive Mode. Where do I select EIM?

    The rule for the XW inverter is a minimum bank size of 100 AH per KW of inverter capability. Your 6048 is capable of 6KW so technically you need a minimum of 600 AH. Given your light loads, you MIGHT be able to get by with less but the smaller the bank, the more you beat on it.
  • BB.BB. Super Moderators, Administrators Posts: 28,186 admin
    Re: XW 6048 - Enhanced Interactive Mode. Where do I select EIM?

    Just to be clear, the 100 AH battery bank rating per 1kW of inverter (or even solar array) is at 48 VDC bank...

    A 24 volt bank would be 200 AH per 1kW...

    And a 12 volt bank would be 400 AH per 1kW inverter...

    Also assumes that the 100 AH @ 48 volt battery bank can support roughly 2kW of surge power (starting well pump, etc.)...

    The math for surge, assuming C/2.5 derating:
    • 100 AH * 48 volt * 1/2.5 = 1,920 watts of surge

    Note: I carry out all digits so people can (hopefully) repeat my math... Any answers/guesstimates within 10% are "the same".

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • DustyDusty Solar Expert Posts: 271 ✭✭✭
    Re: XW 6048 - Enhanced Interactive Mode. Where do I select EIM?
    BB. wrote: »
    Just to be clear, the 100 AH battery bank rating per 1kW of inverter (or even solar array) is at 48 VDC bank...

    A 24 volt bank would be 200 AH per 1kW...

    And a 12 volt bank would be 400 AH per 1kW inverter...

    Also assumes that the 100 AH @ 48 volt battery bank can support roughly 2kW of surge power (starting well pump, etc.)...

    The math for surge, assuming C/2.5 derating:
    • 100 AH * 48 volt * 1/2.5 = 1,920 watts of surge

    Note: I carry out all digits so people can (hopefully) repeat my math... Any answers/guesstimates within 10% are "the same".

    -Bill

    Thanks Bill, for that great information regarding surge requirements!

    Ok, to recap....because I have 2Kw in solar panels (after derating), I should have at least 200ah of battery capacity---however, if I plan to have large loads which demand the max output of my inverter, then I should have 600Ah of capacity for the 6048.

    In my situation, I bought more inverter than I need (hedging my bet for future growth). My geothermal heat pump is not tied into the inverter, nor is the stove or water heater. So, the largest surge I have are the chest freezer compressors (I don't have any equipment for storing surge readings), and the highest constant output is about 1.5kw when the microwave is running for a couple minutes.

    As long as I can keep the battery bank charged with the solar array I have, I will upgrade the batteries to at least 200Ah but preferably 400Ah for additional autonomy when the current ones are used up (since I can't add new batteries to the existing bank).

    In my situation, my daily use is less than 18Kwh. I'm still tweaking settings, but my best daily harvest so far has been 10.3Kwh (at 48V), which is about 214 ah. So, if my rule is to never drop my battery bank below 50% if the grid goes down (actually, I use 60% for my max DOD), my array could support a 400ah battery bank and recharge it completely on a sunny day. Since power outages in my area (even after hurricane Isabel in 2003) have never been more than 12 hours since I moved here in 1997, and I have a 6500-watt generator, I wouldn't install more than 400ah worth of batteries for purchace and replacement cost reasons, as well as storage limitations. Does that seem reasonable?

    The battery enclosure in my attached garage holds 8, automotive-sized AGM batteries in width and depth (with 6-8" of air space around and 1" between them, but I have about 24 inches in height to work with. I don't think I'll have a problem storing 6V, 200ah AGM batteries in that enclosure, but there wouldn't be enough room for 24 2V batteries. I'm also trying to keep the weight of the batteries at a single-person managable weight--120 lbs or less, so I'll have to do some research to see if 400Ah batteries can fit in that area.
    XW6048, 3.4KW PV, Grid-Tied, always tweaking.
  • gridmangridman Registered Users Posts: 18
    Re: XW 6048 - Enhanced Interactive Mode. Where do I select EIM?

    Three days ago I got my solar panels hooked into the system I've been using in utility backup mode for the past year. Now, I'm running in Grid Support - Enhanced Interactive Mode and I'm not selling to the utility. I have Version 1.07 BN of the firmware, which is the latest, I think.

    The solar is powering most of my loads but I am still using 150w to 200w of AC1 (grid) power during the day. From reading many other threads, it appears there is no way to get this down to zero when I have part or full sun (enough solar power to take care of my loads). Is that correct?
  • DustyDusty Solar Expert Posts: 271 ✭✭✭
    edited July 29 #39
    Well here it is, a little more than 6 years since I started this thread, and my AGM battery bank is still alive.  Still only 110Ah of capacity, but I think the dependability of the grid in my area has been the major contributor to their continued lifespan.  They've only been below 95% of capacity four times since I installed them.  I really dodged a bullet last year with all the major hurricanes missing the Outer Banks area.  I know that if I really need several days of autonomy, my battery bank just won't cut it and I'll have to break out the generator.

    So, I've been researching the Simpliphi LiFePO4 3.5Kw 48 volt batteries.  Because of their reduced size, I have room to install six of them where my existing AGM bank is. Six Simpliphi batteries would give me 414Ah of capacity (actually, 331 at 20% SOC).  But wow, do they cost a ton of $!  But they can also be discharged down to 20% of capacity, so the net increase in capacity from my existing bank would be very significant.

    I had some issues today after breaking out my old XW configuration tool in order to upgrade the Firmware in my SCC and SCP.  Those old USB-CAN device drivers aren't supported by WIndows 10, and I was having a heck of a time finding new device drivers on the Schneider website.  Finally, after a call to tech support and about two hours on the phone with a tech who took over my PC, he still had a lot of trouble getting it done. For some reason, their new XW config tool software wouldn't recognize my hardware even after installing the new Windows drivers. He finally had to resort to using the old software I had on the CD that came with my config tool (back in 2010) in conjunction with the new Windows 10 drivers in order to get the firmware upgraded.  Once that was done, the new software started talking to my hardware.  There was no firmware update for my XW6048 inverter, but the SCP and SCC are updated to version 1.0.8, and the SCC will now support LiFePO4 batteries.  Here's hoping the price of those batteries goes down significantly before my existing battery bank gives up the ghost!
    XW6048, 3.4KW PV, Grid-Tied, always tweaking.
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,140 ✭✭✭✭✭
    I would not hold my breath waiting for LFP to drop. They are going up, if anything at this time.

    Six years is pretty good with an AGM. Things have changed a bit since then and most use the combox. The screen shot below also goes out to the web and can be monitored anywhere in the world. The Lithium bank in the shot generates Soc and all battery data from its BMS so no shunts are required. The Simplyphi will require a monitor and shunt.

    We brought our sailboat into some of the gunkholes in the banks. Pretty shallow but we did it. Where are you there?




    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • DustyDusty Solar Expert Posts: 271 ✭✭✭
    edited July 29 #41
    I'm actually in Chesapeake, VA--about an hour north of Nags Head.  We generally get hit by the same hurricanes that hit the outer banks.

    I was looking at that combox--pretty reasonably priced too. It's on my wishlist.

    I installed a shunt in the Midnight Solar E-Panel that came with the Victron BMV-600s battery monitor. With that and the combox, I think I'd be set.  But $2.8k per LiFePO4 battery is a lot, even with the additional capacity in a smaller footprint.  I'm really limited in space for the batteries, and the energy density of the lithium batteries was really appealing.
    XW6048, 3.4KW PV, Grid-Tied, always tweaking.
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,140 ✭✭✭✭✭
    The monitor would have to be a Schneider to get Soc into xanbus for the combox. Generally LFP systems are about 1K$ per useable KWH.
    Gotcha on the Chesapeake. Nice area!  Still shallow :'(
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

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