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Remotely turn on/off solar
#21
Is that your "Batrium WM4 sticky state?" thread? If not, maybe you should open a new thread and give as much details as possible to what it's doing.
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#22
Tell us about how the batrium system is wired (up load some detailed pics) & like Korishan says, tell us what it's doing wrong (again, pics of batrium screens pls).

To stop overcharging, your solar controllers should have suitable voltage targets set?

You don't have to have the solar switch off on the roof, just before the charger controllers.
Running off solar, DIY & electronics fan :-)
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#23
Solar Charger is set at correct voltage and working correctly.  When it hits top voltage it switches to CV mode and starts drawing fewer and fewer watts to eventual zero.

The problem is that sometimes half (or some number of) the mons get caught in a state where they THINK the cell voltage is still too high and continue burning the voltages of those cells down.  This causes the overall batt voltage to go down, which in turn signals to the charge controller to start revving up the production of charge into the battery to top it off.  So at this point other cells (not having the issue) start overcharging more and more, even as they try to burn down as well.  And of course that charge controller has no visibility into individual cell voltages only the overall battery (really this was the whole point of the BMS, to balance individual cells).

I discovered some time ago that if I 'device sync' it will fix the problem by resetting each mon.  But it's only a matter of time (minutes, seconds sometimes) until it happens again.  I've managed to make an autohotkey script that uses mouse movements and clicks to simulate dev sync and run it over and over every 5 mins during the middle of the day.  This only works because the program is (fortunately) the ONLY thing run on that old laptop which is dedicated to the solar/batrium process.

Here are pics of the battery but the wiring is a mess so I don't know how much they will help.

https://s3.amazonaws.com/nm0.dynu.com/Ba...agLeft.jpg
https://s3.amazonaws.com/nm0.dynu.com/Ba...gRight.jpg
https://s3.amazonaws.com/nm0.dynu.com/Batrium/Front.jpg

48v - 16s 4p   Headway (LiFePO4)
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#24
If you get a problem where the mons gets stuck you have something very badly on going. They should NEVER EVER hang in such a state and if they do that you have an wiring issue im pretty sure of.

You should sort that instead if you ask me. And untill its sorted do not use the system.

Have you talked to Batrium about the issue? -> If you havent you report that issue to them ASAP. Be sure to include the information required on their page and they will help you.
Before that I highly recommend to tidy up the wiring mess and crosscheck ALL connectors so there arent any loose conditions.

Can you replicate the issue or is it random? Like touching wires and so?

I have almost 200 longmons running on several systems and never seen that issue.
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Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 83kWh LiFePo4 | 10kWh 14s 18650 |  66*260W Poly
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#25
(01-21-2019, 09:29 PM)nrm21 Wrote: Solar Charger is set at correct voltage and working correctly.  When it hits top voltage it switches to CV mode and starts drawing fewer and fewer watts to eventual zero.

The problem is that sometimes half (or some number of) the mons get caught in a state where they THINK the cell voltage is still too high and continue burning the voltages of those cells down.  This causes the overall batt voltage to go down, which in turn signals to the charge controller to start revving up the production of charge into the battery to top it off.  So at this point other cells (not having the issue) start overcharging more and more, even as they try to burn down as well.  And of course that charge controller has no visibility into individual cell voltages only the overall battery (really this was the whole point of the BMS, to balance individual cells).

I discovered some time ago that if I 'device sync' it will fix the problem by resetting each mon.  But it's only a matter of time (minutes, seconds sometimes) until it happens again.  I've managed to make an autohotkey script that uses mouse movements and clicks to simulate dev sync and run it over and over every 5 mins during the middle of the day.  This only works because the program is (fortunately) the ONLY thing run on that old laptop which is dedicated to the solar/batrium process.

Here are pics of the battery but the wiring is a mess so I don't know how much they will help.

https://s3.amazonaws.com/nm0.dynu.com/Ba...agLeft.jpg
https://s3.amazonaws.com/nm0.dynu.com/Ba...gRight.jpg
https://s3.amazonaws.com/nm0.dynu.com/Batrium/Front.jpg

48v - 16s 4p   Headway (LiFePO4)

In your pictures, what are the wires (several white, green, red, black, etc that seem to come from the two flexible conduits & connect mid pack)?
See attached pic   
You should not have anything connected "mid pack" other than monitoring (ie cellmons only) - eg no solar, no loads.
All loads & solar charge input etc should connect (hopefully via a current measuring shunt) to the 0V & +"48V" terminals of the pack only.

When you measure the voltage of your cells with a multimeter, what are they?  Are they actually "high"? 
The "full" voltage for each of your LiFePo4 cells should be approx 3.40 or 3.45V 
You have a "48V" system, so that's 16 cells in series, so 
3.40V x 16 = 54.4V as the "full" voltage CV cut off in the solar charge controller (or
3.45V x 16 = 55.2V). 

Once the cellmon units have been correctly synced, they can act independently & bypass, etc ie if the Watchmon looses communications with them.
Running off solar, DIY & electronics fan :-)
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#26
Daniel:

Yes I highly suspect it IS a wiring issue.  Because... none of the wires were long enough when I bought it so I was forced to re-splice every single wire to be longer than the original 200mm.  The black tape in the pick is a spice point where re-soldering happened.  What I'm hoping to do is find some way of figuring out which wire is bad via process of elimination without having to remove each wire all at once as this can be quite burdensome.  I guess I COULD use the continuity check on my digital multimeter for each wire... but I need to find a very small pin to go into the holes on either side since my probe endings are too large.

I haven't scheduled time w/ Jaron yet.  My fault not his... life got in the way (had a family member need to go to ER/hospital recently so... life things more important than solar/batteries sometimes).  I'm slowly getting time to deal with the issue more these days.



Redpacket:

Yeah ignore those wires.  They are leftover from a previous BMS I no longer use and are electrically disconnected to anything... but I leave them on there since they are useful to prob between +pos -neg of a cell with my multimeter, without having to reach down behind the things I sometimes put in front of the battery.   I use it just to get a second opinion on cell voltage.  I may remove them soon though.  If there is one thing the Batrium has never been wrong on, it's disagreeing with my digital multimeter more than a few 100ths of a volt on any given cell.  Before Batrium however... you'd be amazed how off some of these cheap shitty Chinese BMS's are.  Made me want to CONSTANTLY check my cells using my DMM out of paranoia.

I do allow my batt to go to about 3.51-ish (3.6v is the do not exceed line). Maybe I will consider lowering SCC top threshold even further a bit. Fortunately LiFePO4 can tolerate some overcharge as it's a safer cathode than the others (LCO and LiPo will burst into flames if you look at them the wrong way from what I hear).
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#27
Good those wires aren't connected :-)

It is very tempting to charge the cells to a higher voltage but you will shorten their life if you do repeatedly.
They will get to "100%" charge at 3.40V just fine. LiFePo4 do not like sitting floating at higher voltages.

What voltage are the cellmons set to start bypassing?

re tracing wiring faults, the batrium gear gear has a network test mode:
https://www.batrium.com/pages/how-to-tes...a-watchmon
Following this might help if you haven't already?
Maybe enable this mode then wiggle the wires slowly to see if you can find a break.
Running off solar, DIY & electronics fan :-)
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#28
Float charge start at 3.5 for me right now... I might lower that also. Thing is I can do that remotely right now, but can't remotely set the inverter (gotta be home for that to press buttons, no RDP into my box). And if I don't do them in tandem... then they start burning down while the inverter is still filling them up... makes for a lot of unnecessary heat and that's also no good. For me it's a slow tweak process, I make minor changes day by day and monitor to eventually get to what I want in the settings. I find that the best way.

I do notice the flat charge curve, where for hours my batt is slowly moving in the morning from 3.10 to 3.45 (when I know i have full solar for hours) then rapidly goes up to 3.60 at the end. But, if you say 3.45 is full I'm curious why the setting in the latest Batrium firmware for "LiFePO4 Long Life" is still 3.5v or <bypass volt> setting.
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#29
3.5 is known Long life. I use that to and bypass is 3.51 kind of. They generally have max around 3.65 and can take 4v easy Short term.

I have float and bulk at 3.5v and then the life Will drop down till just below 3.35 or so. Thats how life works.
The Ultimate DIY Solar and build place
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 83kWh LiFePo4 | 10kWh 14s 18650 |  66*260W Poly
Upcoming: 14S 18650~30kWh | Automatic trip breakers, and alot more
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#30
I do really like the safety of LiFe... it has gotten me out of a pickle more than once. And by pickle I mean, saved me from burning my house down. Tongue

Everyone should use LiFePO4. I just wish the cost/kwh were as little as NMC or NCA or some of those other 18650 ones coming out today. But I can't find them under around $400/Kwh new even if I go straight to factory via alibaba and cut out all middleman markup costs. And used... well, it's hard to find them used because... I guess no one wants to give them up. Tongue Besides the lower energy density makes they crappy for 18650 format so there's all these weird prismatic "brick" formats and "headway" formats (with and without screw ends).

Unrelated side note... LiFePO4 uses no cobalt... so no child slaves in Congo were killed by a local warlord in the making of these batteries.

Wish I could say the same for the rest, "blood cobalt" is the new "blood diamond" that no one talks about.
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