Top-balancing Pytes V5 with Ecoworthy All In One?

[SolarUKWM]

System: 2 x Pytes V5 48V Server Rack Batteries (total 200Ah) PACE BMS connected closed loop with Ecoworthy 5000 All In One.

Is it worth occasionally doing a non-comms-controlled charge to let the batteries "top balance"?

Motivation :-

When monitoring a BMS controlled charge, it charges at constant current (40A set) from start to finish, and immediately terminates the charge at 56.5V/40A = 100% reported SOC. That's a rather sudden stop.

This is not the charge profile I'm used to for Lithium-anything or Lead-Acid batteries: CC up to the voltage limit, then hold at voltage limit (CV) until
current falls to a threshold. Then either stop, or change the voltage set point to a lower "float" voltage.

When charging without comms connected, the same constant current to 100% SOC occurs. But then, it spent a further half an hour held at 56.7V (the CV part!), with the current slowly falling 40A -> 2A, both batteries and Ecoworthy showing as "charging".

At which point the charge stopped, as it went below my 2Amp limit, but could have continued further.

This is what I would consider "normal charging" profile. CC, CV, terminate.

I think: This CV final phase/absorption/whatever you call it is needed to let the cells top-balance off and for the BMS to discover the *real* 100% charge point, and reset the coulomb counter? Otherwise, when does top-balancing get to happen?

But is it something that needs to be done often?

There doesn't seem to be any controls for changing charging behaviour to hold beyond 100% SOC -- other than cutting comms with the BMS.

Thoughts welcome!

Mike.

 

[SunDave]

Hi Mike,
I have some Pytes, but the 48100R instead of the V5. No heaters in mine. I have solar assistant, and I marked out roughly what the charge looks like graphically on my batteries. In the image below, you can see that it charged for about 2 1/2 hours today, then lets the voltage settle, then there are very small charges to balance the cells. The battery current picture from the same charge shows what you were seeing. A lot of amps going to the battery, then very little during the balancing.

This is normal on my Pytes batteries. I have 6 of them in parallel, and they have been in service for about 18 months. They get charged fully, and still report 100% state of health at this time.

Any other questions, let me know. You don't need to push more amperage to them longer, especially if they are relatively balanced from frequently getting full charges. The very last image shows steep drop off of the battery current graph, but zoomed in. It does indeed step down, but only over a few minute period. You would have to be watching the amps pretty close to catch that.

----------

If your batteries are reporting 100% via communications, and everything is working well, I personally wouldn't mess with a forced non-communication charge.

 

[Oldphile]

FWIW, this is BMS SOC, voltage and current for my Pytes V5 batteries. Charging source was PV.

 

[SolarUKWM]

he battery current picture from the same charge shows what you were seeing. A lot of amps going to the battery, then very little during the balancing.

Hi, thanks for replying!

What I saw (and measured, because this is a new system and I'm watching everything closely!) is that charging was constant current until the BMS reported 100% SOC and an instant stop. No obvious balancing occurred. Charging LED on the ECO-Worthy went out -- I'm done! And the battery LEDs changed from charging indication to idle, as loads were on bypass/UTI mode.

This was an AC charge, so no rough-graph-look like yours from solar. I was monitoring V/I every 15 mins at first, then hourly until it started getting closer to "end", then literally standing there watching. I _am_ my own Solar Assistant at the minute ...

My thought was more along the lines of this -- there is a lot mentioned about BMS and balancing in regard to 16S battery strings, for good reason. If the BMS calls 100% when it has counted-in as much charge as it counted-out, that does not really equate to 100% unless it started at a genuine 100% in the first place. All it is saying is "this is as high as I've been before". Right?

For every extra bit of charge that passes through _after_ 100%, the BMS needs to revise its idea of "full" upward until ... all? the cells report hitting their limit voltage, and are effectively no longer drawing a current.

Obviously I don't want to "push" current through them unnecessarily. However -- the inverter and batteries are capable of being operated open loop/no comms, and that charge profile does mean the charge continues until the current falls below e.g. 2.0A with the expected CC/half hour of CV/stop pattern. Closed loop charging gets me CC/stop.

To truly know what 100% is, the battery needs to charge long enough to hit actual 100% _and_ have individual cells start being bypassed as the lesser cells come up to full charge. Once they ALL hit full charge, then it's balanced. That doesn't have to be at a high current, and I would expect that to happen in the later stage -- which is missing here -- where the voltage is held at e.g. 56.5 or higher, and the current falls as the cells reach true full charge. Leaving the BMS to sort out the situation where some cells ARE full, and the lower ones are still catching up.

From having charged single bare cells before, most of the charge does go in during the CC stage, but the CV stage with current being controlled by the cell's needs, not forced, is the final part of charging. I'd expect this to be even more important when dealing with a string of cells.

The subject of top-balancing is mentioned nowhere in the ECOworthy or Pytes manual, so I'm looking to see if this happens during a normal charge (apparently not?) a non-comms charge (could be?) or whether it would take an external charger to do this.

 

[SunDave]

My thought was more along the lines of this -- there is a lot mentioned about BMS and balancing in regard to 16S battery strings, for good reason. If the BMS calls 100% when it has counted-in as much charge as it counted-out, that does not really equate to 100% unless it started at a genuine 100% in the first place. All it is saying is "this is as high as I've been before". Right?

I think I see what you mean now. My understanding is that Lithium batteries have very flat discharge curve. If you look up a graph of it, there is a steep spot for voltage rise when you are finished charging, and a steep drop off when it is out of charge. In the middle of that, it is a very flat discharge curve. So flat that you can't reliably tell where you are at state of charge wise while in the middle.

The counting comes in for the middle part. If you were to spend 5 days between 30% and 80% charge during a series of cloudy days, then the SOC count is there to have an approximate level of charge. Once you hit "full" or "empty" though, there is a clear voltage rise, or fall. That is what the BMS uses to reset to 100%, or to 0%, and start the counting all over again.

So at least in the case of my Pytes batteries (I charge with a Sol-Ark, just a different brand inverter), 100% is 100%. Once it hits that, it's done. What you may be seeing is that setting your charger to voltage, vs. using comms just changes the voltage that you are charging to slightly.

It's possible that your Eco-Worthy inverter handles charging in a slightly different way that I understand. Hopefully others can chime in as well.

I _am_ my own Solar Assistant at the minute ...

I like it! You learn a lot by watching things. Maybe you can catch if your amperage does tick down slowly near the top of the charge cycle. For my Pytes batteries, the max charge amperage called for by the BMS starts dropping off around 90% charge. They linger at 90% for quite some time before reporting 91%. I think this is part of the flat voltage curve/counting issue. The battery only "knows" where it is at when charged or empty.

It's easy to worry about things like you are seeing early on when you don't yet have a baseline for what should happen. If you are fortunate enough to have a somewhat stable system like I have so far, the worries decrease over time, and it just does what it always does. Still fun to watch though.

 

[SolarUKWM]

Once you hit "full" or "empty" though, there is a clear voltage rise, or fall. That is what the BMS uses to reset to 100%, or to 0%, and start the counting all over again.

OK, so there is a voltage rise corresponding to the end of charge. See table at end of post, with single 100Ah pack being topped off.

This is with comms, steady 20A current limiter, max charge/compliance voltage of 56.8V set (but not quite reached), leading to about 4% SOC per 15 mins. Voltage rise, then instant stop of charging mode at reported 100% SOC.

Maybe you can catch if your amperage does tick down slowly

Didn't see that. Clamp meter showed drop to almost zero (+/- noise) and charging LED out on inverter and battery LED indications went from charging to idle. Hard stop! The BMS may see no call to lower the current, as 20A in 100Ah (40A into 200Ah as a pair) may not cause it to worry about overcharging. Slamming it at 100A per pack may trigger that sort of behaviour, I haven't looked!

It's clear that there is an increase in delta-V in each 15 minute period (flat ... 0.1, 0.3/0.4) with a rapid rise at the end.

However: Without the BMS telling the inverter 100% SOC, the voltage does come all the way up to 56.7/.8V, charging continues with a tailing off of current, down to 2A (at which point the inverter is set to discontinue charging). That takes about half an hour more.

I would have thought that top-balancing can only take place if the charger holds the pack at _top_ voltage (e.g. 56.8V or above) for long enough for the lower cells to catch up, while the higher cells get passively balanced (shunted) to keep them. That's the bit I'm not really seeing in the with-BMS-comms charge. It touches max and gives up charging.

You're right, I'm finding "baseline" behaviour so I know what to expect from charging/discharging/mode switching... to me that's normal for any new kit -- watch it, trust-but-verify it, makes notes and file them away. Then, changes I make can be compared to known-previous behaviour. Changes I _didn't_ make ... well then I have something to point at too!

Time	Amps	SOC	Voltage
0:00	20	50	54.2
0:15	20	54	54.7
0:30	20	58	54.7
....	20	...	flat + boring
1:45	20	79	54.8
2:00	20	83	54.9
2:15	20	87	55.0
2:30	20	94	55.3
2:45	20	97	55.7
	20	98	56.0
	20	99	56.1,.2,.3,.4 !!
3:00	20	100	56.5 (stop!)
	0	100	53.5 (resting)

 

[SunDave]

The BMS may see no call to lower the current, as 20A in 100Ah (40A into 200Ah as a pair) may not cause it to worry about overcharging.

I think you are spot on there. You are likely charging at a fraction of the battery max spec.

I would have thought that top-balancing can only take place if the charger holds the pack at _top_ voltage (e.g. 56.8V or above) for long enough for the lower cells to catch up, while the higher cells get passively balanced (shunted) to keep them. That's the bit I'm not really seeing in the with-BMS-comms charge. It touches max and gives up charging.

You won't see much amperage during the balancing. See the zoomed out "Battery Current" chart from my first post. The passive balancers on my 6 batteries max out at about 2.4amps of draw, so .4 amps, or 400 milliamps per battery. It is basically burning off a tiny bit of energy from the highest cells, then applying a tiny charge to the whole group of cells again. Over and over. It shows up as that near 0 amp ripple on the charts above. Some days it barely balances at all since they the cells are very close from yesterday's full charge.

Judging from your chart, you may not be seeing the whole picture, as in more could be happening after you stopped watching. See the charts above again. My system waits for 20 mins or better for pack voltages to settle, then begins the balancing. So it may seem to stop, but you may pick up a fraction of an amp here and there after it rests, if your meter is fast and/or accurate enough.

It is also possible that the inverter is being ham fisted with the charge/no charge algorithm and you are seeing exactly what it is doing.

I like your approach to verify everything. I do the same. I want to know, but also drive myself crazy at times.

 

[SolarUKWM]

You are likely charging at a fraction of the battery max spec.

Battery quotes a recommend max as 75A, with absolute max 100A (1C charging) -- I'm limiting the charge current so that I get from end-of-day's SOC to 100% in approx 7 hours (night rate period) so that I go onto day rate with a recently full battery. Which is marginally better than having run to 100% and then sat for 5 hours.

then applying a tiny charge to the whole group of cells again

I don't see it re-engaging charge ... if left alone, the SOC will drop 100, 99, 98 over many hours -- probably idle draw from the inverter. There is a _voltage_ based setting that says "don't start charging again if I'm above n.nnV" to prevent constant charging, charging and charging again. Nothing in the SOC based limits to stop charging (other than a charge-to target of 100%, which it does).

It may also depend on the "work mode" and "charge mode" in ways I'm yet to discover, I have it in one of two settings: SBU/OSO in daytime (run loads on battery, with no charging as no panels connected) and UTI/SNU (run loads on bypass, battery acts as UPS only if utility fails, charge from utility at night rate).

It is also possible that the inverter is being ham fisted with the charge/no charge algorithm and you are seeing exactly what it is doing.

Probably this! This is why I was looking at the behaviour with and without comms to check it was doing something sensible in all cases. I don't have a separate charger to balance within packs (and to balance between the two packs at new, I connected them individually, topped them off to 100%, swapped over, same thing and only then paralleled them).

but also drive myself crazy at times.

Not knowing is the bit that would drive me crazy!

Depending on how much detail Solar Assistant can get from the inverter/batteries, I may discover it's doing things that I can't easily see/measure ... that's in progress.

 

[SunDave]

Battery quotes a recommend max as 75A, with absolute max 100A (1C charging) -- I'm limiting the charge current so that I get from end-of-day's SOC to 100% in approx 7 hours (night rate period) so that I go onto day rate with a recently full battery. Which is marginally better than having run to 100% and then sat for 5 hours.

That may be the only slight flaw in the plan. The balancing on most lithium systems happens while held at 100%. If there is no time after 100% to balance, then it won't balance. The chart I posted above shows almost 6 hours of balancing micro adjustments before it didn't adjust anymore for the last hour or so while it sat at full charge. Sometimes it only balances for a couple hours. But it does need time at 100% to balance.

There may be a work mode or setting to tell it to stay at 100% for the period of time it is set for, therefore giving it time to balance.

If you are charging from grid, just know there are losses to converting to DC, then back to AC. I would estimate you keep 85% or so of the power in that round trip. If your inverter tracks those numbers, you could see for yourself. Just a handy thing to know in case the electric rates are only 15% different.

 

[SolarUKWM]

The balancing on most lithium systems happens while held at 100%. If there is no time after 100% to balance, then it won't balance

... which is kinda where I came in ... if the charging stops at 100% SOC, when does this mystical balancing get done?

However: I've just managed to get Solar Assistant installed on a RPi4. There is stuff in there about equalizing charges, how many minutes to do it for, etc. that do not correspond with the settings I can see on the Ecoworthy front panel ... I've yet to play with that, but am looking at that to see if it will do something useful.

The manual says that Equalization and it's sub-settings are ONLY valid to be used with Lead Acid and User Defined batteries. I'm using LFP16 so didn't try messing with that, and it is disabled because battery type is L16.

It's possible SA can see some extra stuff that the user interface doesn't let me set. I've already found SA reading back values that can't be accessed on the display, so I have high hopes. At least I'll have some graphs to see if it's doing anything interesting.

Just a handy thing to know in case the electric rates are only 15% different.

Yeah, I'm aware of that. There's losses in the AC in->battery->AC out round trip, and also, a parasitic draw of around 40W from the ECO-worthy being on at all. This is why I didn't go for a larger inverter -- generally, larger inverter, more idle draw, less efficient at lower loading.

But over a complete week of time-of-use shifting (no solar yet, work in progress), my usage has gone up a little, my pounds-and-pence costs have come down, which is a win.

 

[SolarUKWM]

OK, so Solar Assistant watches things more closely than I can by hand ... here's what a comms-controlled constant current charge looks like.

I never noticed, looking in every 15 mins, that there's this weird little SOC-plateau at 90% ... see ...



That's just ... odd. And it's backed up by the front-panel of the Ecoworthy, so not a SA glitch. @Oldphile if your purple trace is SOC, then I see the same thing on yours!

So maybe this period, while the BMS is "sandbagging" and pretending to be only 90%, this is when some internal secret balancing is going on after all, and re-evaluating where "maximum" really is ... and the reason charging is okay to stop-dead at 100% is because the BMS has completed it's secret activities, and so allows the SOC to be reported as 91-99, 100% to hopefully signal to a listening inverter -- "I'm done!"

Still can't see individual cell voltages to know if this is the case, but working on it ...

I would estimate you keep 85% or so of the power in that round trip

Pretty close -- Total discharged from battery, vs total charged into battery is 87% from e.g. Thursday's use recovered in Friday's early-hours.

 

[Oldphile]

@Oldphile if your purple trace is SOC, then I see the same thing on yours!

Yes, purple is SOC and I see that every time. I keep an eye on the individual cells with Solarman via the optional battery dongle. Delta between min/max cells is consistently 32mV.

 

[SolarUKWM]

purple is SOC and I see that every time

Right. So something funny's going on internally, after all -- if there's a constant current passing through and the SOC is going up e.g. 4% per hour -- and those figures balance, then stopping for a break at 90% consuming current and suddenly rushing to the finish is suspicious to me

I did catch a weird plateau at 20% on _discharge_ (In testing, I allowed the pack to run down to 9% to check what alarms/behaviour happened at 15% and 10% trip points).

But -- my estimated timings were off. It got to 20% and then sat there for ages still discharging. Oh come on! I got up early for this!! There's a lot more charge in that 20th percent than the others ... I don't know if that has evened itself out since a few more cycles have gone on.

 

[SunDave]

Right. So something funny's going on internally, after all -- if there's a constant current passing through and the SOC is going up e.g. 4% per hour -- and those figures balance, then stopping for a break at 90% consuming current and suddenly rushing to the finish is suspicious to me

I see what you are saying. I went through many of the same questions early on. That's why I can say with some confidence that you may be worried about nothing. Draw a line from your 90% charge to full, and the graph looks completely normal. The fact that your system reports 90% for a while until it hits a target voltage is not a problem. My system does that as well, and has been in service for 18 months.

You will see longer delay times on 90% with a slow charge vs. a fast one. Different BMS systems report in different ways, but here is the main takeaway. All of the middle SOC percentages are a guess based on how much energy has been used and added back since the last full charge. Your system can only really tell by voltage where the SOC is at on the very high end, and low end of the voltage curves.

That said, it makes sense why your system would dwell at 90% for quite some time at a low charge rate, especially if you have not had a full charge for a few days. There is no accuracy in the middle SOC% numbers unless it has recently calibrated to a full charge.

Does that help?

 

[SolarUKWM]

you may be worried about nothing

This is entirely possible!

Your system can only really tell by voltage where the SOC is at on the very high end, and low end of the voltage curves.

This disturbs my brain a bit though.

In a no-comms-link situation, sure, the inverter would have to guess SOC based on voltage, which is known to be unreliable (flat profile = massive uncertainty) and also the load applied makes the voltage move up and down, causing guesstimated SOC to go up and down too. But in that case, the inverter doesn't report a SOC figure at all. It falls back to using voltages for when to alarm/bypass/shutdown at the lower end, and when to stop charge/bypass at the upper end.

But this is with the inverter talking to the BMS in the batteries -- which should be (and I feel, _is_) based on the current flowing in and out/coulomb counting. It does not suffer from SOC going up and down with applied loads, even though the voltage does fluctuate. It's a PACE BMS, model number not known.

Agreed, the BMS may not fully know where 100% is _until_ a charge goes on long enough to cause all the cells to hit some maximum voltage threshold. Hence the whole "can I force it to top-balance?" question, because the observed behaviour with BMS connection is that it doesn't get time to do that. But, maybe it _is_ doing that in the 90% plateau ... always reliably at exactly 90% too.

especially if you have not had a full charge for a few days

Full charge is achieved every day. That's because I set the charge current based off SOC at 00:30 and then switch to allow grid charging at night-rate. The aim is to fully charge in 7 hours. No more, as charging is banned again from 07:30 (day-rate). And not-much-less, so the batteries are fully topped off at start of day.

Draw a line from your 90% charge to full, and the graph looks completely normal

I did mean to comment on that, must've forgotten. That's why I never noticed that behaviour with manual monitoring. Every 15 mins wasn't quite enough to spot that kink in the graph -- of course SA sees it all!

 

[SunDave]

Looks like your system is working well.

if the charging stops at 100% SOC, when does this mystical balancing get done?

Regarding this. Consider an analogy. You have a bucket that you fill with sand.

You put about enough sand to fill it to the top. You are at 100% charge. Now some of the sand is over the top of the bucket, and there are some dips in the sand. The balancing procedure either:

• Removes the peaks and tosses them outside of the bucket (heat loss in the battery). Then adds some new sand to the valleys. Called passive balancing. Eventually smooths out the sand to be perfectly level with the top of the bucket.

OR

• Pushes the peaks of sand into the valleys to perfectly level out the sand (battery charge) in the bucket. Called active balancing.

Notice that neither of these methods increase or reduce the amount of overall sand (charge), but rather balance each area of the bucket (cells) to be the same level. That is how balancing can be done even after the SOC reaches 100%.

Each BMS works differently, so this is not a perfect analogy. Some BMS systems could be balancing before they claim 100% SOC. How exactly the battery computer reports its percentages is not as important as the fact that it functions well.

 

[SolarUKWM]

You have a bucket that you fill with sand.

I like this. It deals with shuffling about the existing charge in the battery pretty well. That's passive/active balancing that goes on all the time, I'm more than happy to let the battery get on with that.

I'm talking about charging/occasional top balancing, especially on a new "unconditioned" battery _pair_ in parallel.

Let me show you another bucket

I've got a big bucket. It has some sand in it, about half full, and a line marked MAX that I can objectively see is about three quarters of the way up. But that is the fullest that bucket has ever been. Let's call that 100%

I've told the guy standing next to it to fill the bucket. He starts pouring sand in, and when it hits that line, he stops and says "FULL!". That's what my charger does when it has comms with the batteries. I can never convince the guy to fill just a little more to discover that the MAX line could be, and should be, higher.

If I blindfold the guy, and ask him to fill the bucket, he goes past that mark, until he feels sand dribbling on his toes. Then he says "Wait, must be full!" and stops. At which point, the MAX line has now come up to the rim of the bucket.

Now, when he fills the bucket, he still only fills it to the MAX line, but that MAX line is in the proper place.

(See also "I've never drained my fuel tank below 'half full', I consider that to be 'empty' drivers)

Before you say "that's nuts!" ...

I've recently gone and looked in the Pytes serial console. There's a log in there of events and history. I won't post it here but there's an interesting feature.

From new, the pack reports charging, idle, discharging, in a cyclic order as I'd expect. All of the charging done by comms link.

Then there was a weird entry in there. Charging/COULFULL which corresponded to me "forcing" it (no-comms, voltages only) to complete the charge -- that is, instead of CC charge terminating at 100% it continued at CV (56.8/57.2V) with the current tailing off over half an hour.

A similar thing happened just after that deep-discharge "plateau" at 20%. If I'm pulling current/charge out, then 20% SOC shouldn't stay there so long. My theory is the BMS was discovering some new depths and re-assessing how deep it _could_ go... and then there was a COULLOW entry when it hit 19%, carried on down to 9% at which point I stopped discharge. When charge took over, COULNOR was flagged at 9%.

Someone with deeper knowledge of the PACE BMS would need to explain those messages, I'm getting no Google love there.

What I have noticed is that since doing that, the SOC between the two batteries is closer. Previously, there was a lag between the SOC LEDs on the front panel (one battery would lose/gain a 10% LED before the other) even though both batteries were taken to an identical "100%" (hmmm, or so I thought!) before I paralleled them, and the cabling is an identical number of inches for each battery.

That lag has gone. They are now within 1% SOC reported of each other, so maybe I've mostly achieved what I needed to do.

I'm sure an external charger that does a full CC/CV LiFePO4 profile could sort this out. But at the moment the only charger I have is the ECOWorthy AIO unit.

 

[fcopurico]

I hope you do not feel I hijack your thread. But SunDave said previously

I think you are spot on there. You are likely charging at a fraction of the battery max spec.

You won't see much amperage during the balancing. See the zoomed out "Battery Current" chart from my first post. The passive balancers on my 6 batteries max out at about 2.4amps of draw, so .4 amps, or 400 milliamps per battery. It is basically burning off a tiny bit of energy from the highest cells, then applying a tiny charge to the whole group of cells again. Over and over. It shows up as that near 0 amp ripple on the charts above. Some days it barely balances at all since they the cells are very close from yesterday's full charge. ...

I been asking if my Pyte E-Box-48100R behavior is correct, constantly drawing little currently, some of a minimal ripple. Here better seen at the morning when power are small.


SOC 100% but, see the constant battery power in blue. Pbat is about 50-70W
SOC 100% but at 7:25 SOC show 99%, then Pbat increases very little to 284W.
SOC go again to 100%


At 8:20 SOC show 99%, then Pbat increases very little to 93W. Just to go back SOC to 100%

Here hope you can see better what going on.


Now what concerns me is the accumulative power been consume. In a full day it can add up to 2.5 kw. That is in fact a big amount of energy for a 20.48kw battery bank of 4 5.12kw. A battery that is not been use.

I am knew to Solar Energy.
From what you wrote it seems to me you are seeing 400 milliamps per battery on Pyte's V5

My last figure shows my 4 bateries draw about 1.5A constatnly. 1.5 / 4 = 375 milliamps per battery on Pyte's E-Box-48100R

My question is:

It Is this normal for my 4 pytes to consume 2.5 kw a day just sitting without been used?

Lets say you do not have Pyte. The question will be: It Is this normal for a 5.12 Battery pack to consume 625 watts a day just sitting without been used?

Thanks ahead
Frank

 

[SolarUKWM]

I hope you do not feel I hijack your thread.

No, hijack away!

It Is this normal for my 4 pytes to consume 2.5 kw a day just sitting without been used?

It seems high to me, especially if the battery is off/standby. I didn't try to measure this statistic though. With no communications ability other than the inverter, I wouldn't know what was really going on with State Of Charge/Current. Plus idle battery = not getting on with building my project!

In my case, the (small) inverter draws about 40W all the time just being there, so 960WH burnt up each day for that. If your battery is connected to the inverter, what's powering the inverter? The batteries? Grid? How large is the inverter, and what does it say about its quiescent draw -- the power it draws to sit there doing nothing?

The Pytes manual says the batteries lose 1-2% lost per month in standby.

5120WH total capacity, 51WH lost per month, 1.7WH per day, 0.07 watts as a constant load, that's only 1.4mA at 50v unless I messed up my maths. So figure 1.4-2.8mA drain in standby. That doesn't sound like any "balancing" is going on at all, which might be a good thing if the battery is shut down.

Any constant draw from the inverter would be on top of internal losses in the battery.

 

[Oldphile]

It Is this normal for my 4 pytes to consume 2.5 kw a day just sitting without been used?

My Pytes V5 consume 0.1KWH per day.

 

[fcopurico]

@

... With no communications ability ...

I do have BMS Cable hook to Solark 8K. And using the idea @Oldphile posted figure with BMS info. Here is mine:



HAHAHA BMS claims it uses NONE or 0 A constantly except for the 9 A Spike at 12:09 PM.

In mySolark reports for consumption ( at 4:30 PM )

See how SolArk 8K blames 1.5 kw for "Charging".

But without having a way to measure real current between SolArk and the "Victron Lynx power in 1000" bus-bar I do not really know if in fact that current/power lost is reality the SolArk internal Charger that consuming the energy?

I guess the only other thing I can do is try every battery by itself, with the hope( or sadness ) to find one of the 4 Batteries doing what the others do not do.

Well I can see if I can do the modbus or serial reading. But at the moment I do not have RS485 adapters.

On Mysolark app I should be able to look at
APP>Equipment>Battery
But it is like no BMS data get to mysolark, or that I am not entering the require info.
Also I can look at mysolark export option. But no BMS data is exported.

My Pytes V5 consume 0.1KWH per day.

That is for 1 battery or for the 4 bank?

 

[Oldphile]

@

I do have BMS Cable hook to Solark 8K. And using the idea @Oldphile posted figure with BMS info. Here is mine:View attachment 288798

View attachment 288804

HAHAHA BMS claims it uses NONE or 0 A constantly except for the 9 A Spike at 12:09 PM.

In mySolark reports for consumption ( at 4:30 PM )
View attachment 288802
See how SolArk 8K blames 1.5 kw for "Charging".

But without having a way to measure real current between SolArk and the "Victron Lynx power in 1000" bus-bar I do not really know if in fact that current/power lost is reality the SolArk internal Charger that consuming the energy?

I guess the only other thing I can do is try every battery by itself, with the hope( or sadness ) to find one of the 4 Batteries doing what the others do not do.

Well I can see if I can do the modbus or serial reading. But at the moment I do not have RS485 adapters.

On Mysolark app I should be able to look at
APP>Equipment>Battery
But it is like no BMS data get to mysolark, or that I am not entering the require info.
Also I can look at mysolark export option. But no BMS data is exported.




That is for 1 battery or for the 4 bank?

That's for all 4 batteries.

 

[SunDave]

It Is this normal for my 4 pytes to consume 2.5 kw a day just sitting without been used?

SolarUKWM is spot on. I think it is more likely that your inverter is taking the approx 2.5kWh per day, and you see that reported on the battery stats. Not sure though. Your graph shows all the power used at one time in intervals...

Do you know what your inverter consumes for power? If you add up all your inputs and outputs for any given snapshot in time, then you can see what is "missing". That is normally your Sol-Ark's usage. In the example below, my load is currently 540 watts, the battery is supplying 592 watts.

592-540=52

52 watts is being used by the Sol-Ark right now. In higher usage times of the day, more than that will be used. I don't believe this is reported in the recorded data, which does get confusing if you don't know that the usage exists.

I am knew to Solar Energy.
From what you wrote it seems to me you are seeing 400 milliamps per battery on Pyte's V5

That's only when balancing on my batteries. From what i can tell. Not a constant drain at that rate.

 

[SunDave]

That lag has gone. They are now within 1% SOC reported of each other, so maybe I've mostly achieved what I needed to do.

Good to hear you are making progress. I think once a battery is somewhat balanced, you should get very near your 5.12kWh per pack. That is how the 100% would be determined in the real world. How much energy can you get from them before low voltage shut down.

 

[SolarUKWM]

Do you know what your inverter consumes for power?

@fcopurico The manual may mention it somewhere. It is something Will mentions when reviewing inverters/All In Ones -- that idle consumption can be quite high on some models, and in some use cases may really be a significant loss.

Otherwise, you can try and calculate it, or, if you have a clamp-on ammeter, you might be able to measure the current flow from battery bank to inverter when the inverter is on -- but not running any loads.