I have snow showers happening today and for the next 2 days, and may or may not get a full charge by the end of the day.... I'll capture and post the next good data set confirming whether the current settings result in proper charge behavior or not.
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November 6, 2024 2:49 pm
November 8, 2024 10:52 pm
Sun came out today and charged system to full.... verifying that the charge curve is NOT doing what I programmed. The 6000xp is holding end-of-charge voltage (56v) for three hours rather than dropping to float at 54.0 right after hitting EOC voltage as programmed.
The 6000xp charge firmware really needs a patch for best performance and longest life from LFP batteries.
Correct CC/CV charge for LFP should charge at a max current possible to float voltage, then CV to end of charge voltage, then immediately drop to maintain at float voltage..... and reset overnight (indicated by zero PVinput for more than 4 hours OR by voltage dropping to ACchargestart or GeneratorChargeStart voltage).
This issue should not be closed until patch is available, available for download/update, and documentation and release notes have been distributed to ALL registered 6000xp accounts.
November 10, 2024 6:11 pm
I have FINALLY found a combination of charge voltage setpoints that appear to give a "correct" CC-CV charge curve for LFP. I think EG4 still needs to dig into why it is so hard to get a LFP charge curve if you want open loop communication, and they definitely need to document these settings as an example to help people understand how to program a LFP-friendly curve.
batt type= lead-acid
amp-hrs= xxx
Vcharge= 56.2
Vfloat=54.0
Veq=54.4 , days=0, time=0
November 25, 2024 5:56 pm
system reverted to "bad behavior" for some reason.... floating at charge voltage ?! really, really, really NOT what I want. When can we expect to see a firmware update that fixes this reliably ?
January 18, 2025 5:15 am
I wouldn't have gotten the eg4 6000XP had I known it was so wonky with charging lithium batteries. Hopefully a firmware update fixes this.
January 18, 2025 5:23 pm
@ouijifour , version= ccaa-190D0E seems to be "fairly good" most of the time. I see a CC/CV charge curve "as programmed" most of the time, but have noted a few days with partial clouds cause the end of charge voltage to go above 56.2v setpoint, or return to 56+v briefly if there wasn't enough time at 54 float in the afternoon.
So, I would say the charge control appears to be "better", but still not rock solid.
January 18, 2025 9:43 pm
@dtbaker61 I see in your settings that you have Veq higher than your float ? Does this do some trick to the firmware to make it work better in lead acid mode ? I don't understand why they have Equalize time but no Absorb Time ? In both the Lead Acid and Lithium modes if there was something in the firmware that just stops it from going to high setpoint again until the next day that might fix the issues . It seems strange that after so many years of lead acid charging history, that not even this Lead Acid mode works correctly. The lithium charge mode should have voltage setpoints in addition to just charging based on SOC% . I don't understand why in Lithium mode it would charge based on BMS SOC % since many people know that BMS reported Soc can get way out of whack after a few days of not getting fully charged and reaching it's setpoint .
When I look at the AC Charge settings it lets you pick charging based on voltage, soc, voltage and time, soc and time. Why can't these options be in the Lithium charge settings ? Seems very odd .
January 18, 2025 10:30 pm
@ouijifour , if you can get the BMS communicating correctly between battery and inverter, you can use 'lithium' and manage setpoints by % since the batteries will be "running the show".
I do not really trust the BMS communication with delicate ethernet connections in off-grid settings, and found the setup of the comms problematic. I decided to use "open loop" (no comms between batteries and inverter), and let the inverter charge controller run the show. with the 6000xp, you have to SET the battery type to Lead acid to enable manual voltage setpoints, and if you are using Li batteries, you do NOT want the charge voltage to hang out at 56.2... you want it to charge to 56.2, and then settle to "float" at 54.0 for the remainder of the day.
so, the setpoints that work for LFP batteries, in Lead-acid mode, are
bulk=absorb=charge= 56.2 , just different terms for stage 1, but for LFP, this actually results in CC/CV charge with current slowing at "end of charge" to enable internal balancing.
float=equalize= 54.0 , and equalize days = 0, time=0... this keeps batteries full until dusk, at which time voltage will settle to 53.3 (no load) pretty quickly. Then "working voltage" between 53->50 or so is fine, warning at 49, disconnect loads at 47 to avoid re-start problems taking LFP too low.
January 18, 2025 10:39 pm
@dtbaker61 Tomorrow I am trying lead acid 55.2 v absorb 53.6 float and 54 v for equalize 0 days and 0 time. I will see how that goes.
January 18, 2025 10:44 pm
you want to use the absorb = 56.2 , not 55.2 .... it is important to get EOC high enough to reset BMS to 100% and balance.
firmware of inverter should be = ccaa-190D0E , earlier versions do not work correctly.
January 18, 2025 10:55 pm
@dtbaker61 My bms is programmed to reset to 100% at 55.2v . I understand what you are saying though that many bms are programmed to reset the SOC at 56v
January 18, 2025 11:01 pm
@ouijifour setting 100% at 55.2 will cause problems because you are never getting to the point where the voltage curve is steep enough to be accurate with lithium. you *really* want it to be 56.2-56.4
January 18, 2025 11:20 pm
@dtbaker61 Have you ever watched Off Grid Garage on youtube ? He has done lots of testing and graphing and explaining the results of voltage , capacity , etc . 55.2v is 99% full . There is not much capacity gain above that point . Andy has all the data and video of capacity tests to back it up .
