Xantrex 3000w inverter issue

[carpenter]

My LiFePo4 batter bank is at roughly 55% soc. It is the 3 battery lithionics set up with 360ah. I went to use the convection oven on microwave setting to warm up my coffee this morning and it will only run for 30 seconds or so before the xantrex beeps and throws code 1. The draw on the microwave should not exceed the available charge in the battery to run for 1 minutes to warm up coffee. I made sure to turn off all other items such as the anti freeze on my truma before using the microwave. This is the second time this has happened, the last time I was roughly 60% on soc.  2022 elite 2 if that gives you any more information. Thank in advance for any input.

[Steph and Dud B]

It's possible your SOC is out of calibration. Have you ever run the batteries all the way down to shutoff then recharged them to full?

[jd1923]

4 hours ago, carpenter said:

I went to use the convection oven on microwave setting to warm up my coffee this morning and it will only run for 30 seconds or so before the xantrex beeps and throws code 1. The draw on the microwave should not exceed the available charge in the battery to run for 1 minutes to warm up coffee. I made sure to turn off all other items…

There must be 10+ threads in the last two years on the 3KW Xantrex shutting down and I’m not saying search vs. posting. Please everybody always feel free to ask any question! 😎

It’s usually something re low voltage cutout. Likely you need to run through setup configuration to lower this number. Experienced Xantrex owners may chime in otherwise, search for ‘Xantrex’ from the forum home page and you should find instructions for changing this parameter.

Also 50% SOC is not LOW with LiFePO4 batteries! We have a Victron inverter with 900 Ah. The Victron allows for this, since we can run our A/C AND the microwave (oven) with SOC <20%!

Both the inverter and batteries have low voltage cutoff protection. I’ve never read here re Lithionics cutting out. The Victron inverter never cuts out. There are only Xantrex cutoff issues.

Also it’s not your microwave given it runs long when plugged into shore power.

Check your Xantrex manual and their Tech Support if necessary. 

[jd1923]

3 hours ago, Steph and Dud B said:

It's possible your SOC is out of calibration. Have you ever run the batteries all the way down to shutoff then recharged them to full?

Is this safe, Dudley? I’ve never let ours run much below 20% SOC or in the teens. I always thought bringing SOC to 100% and adding Float charge for another 24 hours should calibrate SOC% at 100%.

[Snackchaser]

As @jd1923 said, the Lithionics should reset itself if the batteries are kept fully charged while not in use.  The new firmware also helps with this by making corrections at various charge states.  It’s worth updating them.

The Xantrex Code 1 is a voltage issue, it means the inverter isn’t getting enough voltage from the batteries while the microwave runs.  This isn’t necessarily because of low SOC, it’s more likely a poor connection somewhere in the heavy battery cables.  Think of it like a like old car with corroded battery posts, everything works fine until you try to turn the engine over and the connections can’t handle the heavier starting current.

There are some easy checks you can try.  Make sure the inverter’s low-battery cutoff is not set higher than 12.1 volts per Oliver’s recommendation for Lithionics batteries, and that the battery type is set to lithium.  Some owners have found that software updates changed these settings. 

The Victron is a different design, but not necessarily better.  In this case, when the Xantrex trips, it’s warning us there could be a problem.  A Victron with default settings would keep running while a bad connection heats up, until the battery’s BMS protection shuts everything down, including the lights!  Although Victron uses load compensated cutoff, owners should also check their low-battery settings.  The factory defaults are very low, and they should be set per their battery maker’s recommendations.   I've done some fair research into the Victron, and unless you also opt for an expensive Cerbo based system, I believe it's not a better upgrade over the Xantrex.

Another easy test is to watch the voltages from the SeeLevel panel and Xantrex display, then start the microwave.  Note each display’s voltage before starting and just before the inverter trips.  If the SeaLevel (battery voltage) stays about 13 V, but the Xantrex drops to about 12 V, then there is a voltage drop (poor connection) in the wiring  between the batteries and the inverter.    If they both drop together, then the batteries may be weak or not sharing the load evenly.

The 300 amp breakers internal resistance is a an easy first test.  Put a DC voltmeter across the terminals with a full load (while running the micro).  Anything over 0.1V across the two posts is too much internal resistance.  You can also use an infrared thermometer to look for warm (poor) connections after the inverter trips, or run a smaller load, such as a heater on low.  It might not be enough load to trip the inverter, but enough to warm a poor connection.  Don’t forget to look at the grounds!

Of course it might be something else altogether, and there are other voltage tests that can isolate the problem.  This is a good start to help narrow it down.  Let us know what you find.  Cheers, Geoff

[Steph and Dud B]

3 hours ago, jd1923 said:

Is this safe, Dudley?

It is what was recommended by Lithionics: What is SOC Drift and how to avoid it? : Lithionics https://share.google/oh46MD3Ckxst17rsU

2 hours ago, Snackchaser said:

As @jd1923 said, the Lithionics should reset itself if the batteries are kept fully charged while not in use.  The new firmware also helps with this by making corrections at various charge states.  It’s worth updating them.

I was aware that Lithionics had updated firmware that added that function to their *external* BMS batteries but haven't heard about it for the internal BMS batteries yet. "Older versions of Lithionics Batteries do not currently have the automated Usable Ah calibration feature but will receive similar firmware update in the future to enable it." 

I have firmware version 2.1.11

[Steph and Dud B]

Reading through the Lithionics document again, it seems like those of us with internal BMS are supposed to run the battery down to 0% SOC to trigger the calibration. However, those with the V9 external BMS can run down to 10% to achieve the same thing. Does everyone else read it that way? That does make me uncomfortable and I would definitely like to have the new firmware available for my internal BMS batteries.

[Snackchaser]

6 hours ago, Steph and Dud B said:

 Does everyone else read it that way? 

I read it somewhat differently.  Lithionics does recommend fully charging the batteries periodically to keep the SOC reading accurate. 

In the SOC drift document you linked, they cleverly compare it to a leaking bucket with opaque walls.  You can’t see the level, so you have to fill it to the top now and then to know where it stands. Charging the battery to a true 100% (not 99%) resets the SOC to a full bucket.

However, as the battery ages, its amp-hour capacity decreases (the bucket gets smaller).  You can recalibrate the bucket size using a fairly complex procedure to fully charge then discharge the battery.  I don’t think many folks do that, and IMO it’s not necessary for most Oliver owners.  Unless of course there is gross error, say if the battery shuts off while the app still shows 20% or more.  

The firmware updates aren’t so straightforward either.  In the internal BMS firmware, Lithionics added, then rolled back, corrections for large SOC errors because they weren’t precise enough and could make readings worse in parallel battery banks like ours. There still appears to be an automatic correction at the 10% point in some internal BMS models, but it's unclear which ones.  The newer external BMS module actually makes corrections at a number of points during discharge.

Good stuff!  Cheers, Geoff