Hi all, my Blue Smart IP22 charger is not executing repeated absorption at (every) 7 days as configured. It has spent 9 days in storage stage at this point already and no sign that it would go into absorption anytime soon (should have done so 2 days ago).
I planned regular absorption for the LiFePO4 to be able to do it’s cell balancing at regular intervals (may change the 7 days later, currently just testing if everything works, but apparently that’s not the case.)
Right now only the BMS uses energy and the charger charged 10.9Ah back into in the battery during the 9 days while in storage phase which is set to 13.5V. But even if the battery remains at SOC 100% (which it is) that should not stop the charger from executing the configured repeated absorption in my understanding.
I use a custom profile but repeated absorption is configured for 7 days and it is enabled. Absorption time is set to fixed 2 hours. See screenshots from app.
Please let me know if you have an explanation. Thank you.
What does the graph show on th v trend.
In the summary it shows 2hr absorption and there was a V max that looks like it could be absorption figure. Since it matches the other days.
The 10AH would have been what it took to counter the BMS self consumption. Not shown in the bulk but storage section.
The battery wouldn’t have really needed a serious charge since it was likely still balanced and ok.
Thank you for the feedback LX!
I agree the 10.8Ah happened during the storage phase and it is really the charger acting as a power supply to feed the BMS while the battery is basically just sitting there at full charge.
This is great from a system perspective (backup application) because 100% SOC is always available.
Not so great from LiFePO4 life expectancy perspective as it does not necessarily like to sit at 100% SOC continuously forever. But I’m OK with that at this point.
The graph spent the 9 days in the storage phase with the voltage being steady at 13.5V - that is the problem, it never came out of storage to enter the programmed repeated absorption on day 7 (or after day 7).
That Vmax you see there was still during the initial (forced 2hr long) absorption which was due to restarting charger, I agree there was no need for big charge, battery was pretty much full, only took 0.1Ah during the 2 hours of initial Abs.
The history/summary seems to be chronological from bottom up, so first it did bulk for 8 sec then the original Abs for 1h59min (it is set to 2hr fixed) then no Rec, no Float (these are disabled) and then entered storage and remained there indefinitely. According to my configuration it was supposed to enter another Absorption which never happened. Not sure if this would open another block in summary, or it would just add another Abs over the Storage (to keep it chronological) but even if it would simply add the time to the original Abs, now it would have to show more than 2hrs. But again, none of these have happened.
I understand the battery might not have needed another absorption yet, but that shouldn’t matter: if it is configured, the charger should execute it. You see it did the original Abs for 2hrs even though only a few minutes would have been sufficient. But it was configured to do 2hrs so it did it for 2hrs. But again that seems to be not the case with the repeated abs setting unfortunately.
BTW, since then I also added an inverter to the setup and for this I had to disconnect the charger. When connected back, during the 2hrs forced Abs, the BMS did indeed start cell balancing!!! So this tells me the battery definitely needs the repeated Abs cycles, but I wouldn’t want to keep disconnecting (or changing profiles to force new Abs) on a regular basis when there is an actual setting for it (that doesn’t appear to work).
Again thanks for your reply, hope this clarifies the situation further.
Its not really doing that, the voltage is falling.
It would seem the battery itself does not notice the small current.
Do you have the charger as part of a smart network?
I assume you used the lithium profile and customised it?
Since i have never left one for more than 7 days. I can’t confirm. Haven’t seen any other posts here about it but will look. Will be interesting to see if any one else has experienced the same thing.
That would be my understanding as well. Either time will trigger another cycle to absorption or the rebulk offset value.
I would check the voltage trends.
I am wondering if the history has recorded what has happened the right way.
For interest sake, what firmware are you running?
Thank you LX for your comments. Please see my answers below.
FW is v3.61 it says it’s the latest. I don’t have a smart network. Both battery and charger are smart, but only individually.
I was also wondering about how the history would show the repeated Absorption. Maybe it misses visualizing it but that would be strange too.
I was not home when storage reached 7 days, so can’t confirm whether the V actually changed or not.
However, when the battery started balancing last night after I added the inverter (and charge cycle restarted), the BMS reported balancing in progress for about 12 hours, so if one started at day 7, I would have definitely seen that.
I didn’t use the built in Li-ion profile because it has reconditioning enabled. As far as I remember I created my profile from the custom smart lithium LiFePO4, changing a few things back and forth but eventually settling on almost the same in the end, except for slightly higher Abs voltage and deleting float (which doesn’t really make a difference I think as it just skips to storage which is set to the same V as float would be).
As a troubleshooting step, I created a fresh profile from custom profile smart lithium LiFePO4, and only changed the repeated Abs interval to 1 day, so if I get home in time I should be able to monitor the voltage in real time.
Actually, while looking at the profiles I think I’ve just found something interesting…
The custom profile/battery preset “Smart Lithium (LiFePO4)” is pre-defined and generally NOT editable (similarly to the gel Victron, etc. profiles). If you change ANY (well at least all I tried) field in the preset “Smart Lithium (LiFePO4)”, then the preset changes to “User defined” and then you have a chance to save/rename the new set of settings as the user’s own profile. I’m pretty sure this is the intended behavior.
However only the field “Repeated absorption” behaves differently. If you change this, it seemingly just overwrites the value for the active preset “Smart Lithium (LiFePO4)” instead of changing to/starting a new editable “User defined” profile.
Also the new value for the field “Repeated absorption” apparently becomes shared between the custom profiles (again maybe not all but the ones I looked at inherited it).
This different behavior may stem from how the “Repeated absorption” relevant settings are stored and then executed (or not) differently than any other settings.
Please let me know if this makes any sense.
The situation has fundamentally changed with my adding the inverter. Between the BMS and inverter, they pull a quiescent 0.5A with no useful load connected.
As this forces the charger to remain in bulk, I canceled the first cycle in fear of destroying the battery.
Then I switched to the built in preset “Smart Lithium (LiFePO4)” thinking that the lower Abs voltage (14.2V) may help to complete Bulk, but I guess really only the current makes a difference.
The built in preset started a new cycle and also remained in Bulk @14.2V and 0.5A until it reached the bulk time limit (1day) then it completely skipped Abs and it’s been in Float @13.5V and 0.5A for about 4.5 hours now.
I may need to reconfigure to a shorter bulk time limit unless there is a bulk current setting available (I haven’t really looked into detailed bulk settings yet).
As far as repeated absorption, not sure when I would even expect to see that now (again, the setting has changed to 1day even for the built-in preset), having no absorption in this current cycle at all, not sure when the counter would even start…
Partially Correct.
Bulk is the constant current charge where it is trying to reach target voltage.
Absorption is where it is kept at the voltage but uses little current. And will allow the drop to float.
You can shorten absorption and set a time limit for bulk.
But do the calculations first. E.g. used 100AH have a 25A charger - needs 4 hours to complete (roughly)
Thank you again for your support LX! It may not be obvious by my questions but I really love this charger! And I have learned a lot already using/configuring it.
If we look at Vstart = 14.29V on my screenshot, this was after I lowered Vabs to 14.2V (Vabs was set higher @14.4 in my previous, interrupted cycle), technically the charger already reached (was over) the desired target voltage when this last cycle started so it should never even have entered Bulk phase, yet it spent 24 hours in bulk (fortunately at 0.5A for the entire time and not doing constant current at Imax=15A of my charger) to be only stopped by the time limit. In my mind this Bulk phase behaved much more like an Abs phase…
I guess the definitions are only clear for a dumb battery with no BMS and no load whatsoever use case.
But seeing that the current was actually limited and the Voltage settled at the configured 14.2V, I guess I should not be too afraid of overcharging the battery by setting the Bulk time limit to maybe 7 hours (100Ah 15A) even if it is only partially depleted.
The manual says Abs is skipped when Bulk ends by time limit reached so that appears to be by design.
The big question is still whether repeated absorptions will be executed every 1 day as currently configured… I really need that feature for my setup to be “maintenance free”.
I would also be interested to find out.
History still shows 0 time spent in Absorption approx 28hrs after bulk ended. See screenshot attached. Unfortunately I slept through the exact 24hr “anniversary” of the bulk ending so was not there to monitor the voltage in live.
I’ll make sure to be there for the 48hr checkpoint after bulk end.
I’ll also plan to check voltage at the 24hr anniversary of float ending/storage starting though that’s probably the less likely scenario.
Very good news: the charger executed the 1st “repeated” absorption, 24 hrs after entering storage phase. It lasted for 1hr as the manual suggested.
There are telltale signs while it is in progress but as @lxonline suspected, it is not logged in history so there is no way to tell whether it ever happened after the fact. (that’s where my original post was coming from) The time spent in Abs simply adds to the storage counter, not to the Abs counter, which keeps displaying whatever it was before, in my case 0.
During the repeated absorption the charger still considers itself being in a kind of storage phase (see external LED and graph area pictures) and while the elevated voltage is not visualized on the graph, it strangely only highlights the right half of the storage area on the graph, maybe to suggest that something different is going on (?). There are clear “repeated absorption” references including short description on the status screen and under the graph as well. The voltage measures and is also shown properly on the status screen (14.2V in this profile).
Adding a bunch of pics to document behavior. The screenshots with 15:1x timestamp are during repeated absorption and the ones with 16:1x timestamp are after completion and back in normal storage phase.
So the feature works! Thank you for the support @lxonline !
Excellent.
