batrium watchmon4 critical event

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babish

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Feb 10, 2018
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A few times today it looks like the watchmon has shut down: the green led on the blockmon stopped blinking and the watchmon led indicator turned red (which means "Timeout error" according to the faq, whatever it means): image_ddkypx.jpgimage_derocb.jpg



It sounds quite worrying... has it happened to anyone else, and would anyone know what could bethe cause?
I think it happened when I connected my laptop with usb (as somehow I could not connect withwifi) and then the laptop went to sleep. not sure if it could be related.

see some more info about the project there:https://secondlifestorage.com/t-Off-grid-fridge-project-in-west-africa?highlight=west+africa

also a few things I would like to understandabout the watchmon:

- when bypassing current the temperature of the blockmon increases quite quickly to ~80C at some places, I guess it is finebut I was wondering from what temperature the connections cables that are wrapped aroundthe blockmon will start to melt?

-the faq charging settings says "Cell Hi Cutout (CV10): Cell voltage threshold to charge up to, if above will stop when enabled to monitor." buthow the charging can be stopped at the cell levelother than by bypassing current? would the watchmon ever open the battery circuit, which could damage the solar charge controler as I understand it?

- in the attached Daily Session screenshot I am not sure why the Min Cell Volt, Supply Volt, Shunt Volt are all 0, whereas they are reported correctly on the main chart, is it a bug?

already too many questions I guess...

thanks for the help
 
You need forced aircoolingwhen in bypass, unless you reduce the input current.

It sounds like your shunt has locked, there's a RC that's intended to resolve that issue.

https://www.batrium.com/blogs/news/watchmon-toolkit-release-2-0-rc7

babish said:
-the faq charging settings says "Cell Hi Cutout (CV10): Cell voltage threshold to charge up to, if above will stop when enabled to monitor." buthow the charging can be stopped at the cell levelother than by bypassing current? would the watchmon ever open the battery circuit, which could damage the solar charge controler as I understand it?
Click to expand...

You need to configure your system such that the WM triggers either a cessation of charge, or a decrease when the CV10 level is reached. If you keep charging at a high rate the bypass resistors will get excessively hot - unless you actively cool them.

How is your charger linked to the WM, if at all ?
 
the charger is not linked to the WM, I do not think it is possible with the MPPT PCM-60?
I have set the charge controller absorption voltage at 3.5V, ie the same as bypass trigger, so I should never reach cv10 if cells stay balanced; that said I was surprised how quickly they unbalanced under my max charge rate (~0.3C which sounds still quite low) or under higher discharged rate (0.5C); I thought that new same cells would not unbalance much;
 
Linked by way of using either A or B output to cease charge, based on whatever control logic you select.

I suggest that you should also (using a good quality and calibrated voltmeter) check both the actual voltage settings of the charger, as you may find you need to adjust it down a few tenths, and confirm the actual voltage each cell is at when it goes into bypass.

Good quality, well matched cells should stay very well balanced, without the assistance of a BMS.
 
I have installedWatchMonToolkitInstaller_2.0rc7, but now I cannot connect anymore to the WM... I have tried to reinstall theusb driver, to press the prog buttonand to power off the WM, nothing has worked...
 
I was trying but I do not think I can update the firmware if it cannot connect; basically the pop up window open and get stuck at "connecting"
 
In the picture, many of the bolts holding the blockmons to the battery terminals do not look like they have been tightened properly or the bolts are too long and bottoming out in the battery metal post. See the spring washers - they should be pulled flat.

Check & reseat/replug the cables between the blockmons.
In the s/w there is a way to identify communication breaks, see here:
https://www.batrium.com/pages/troubleshooting-cellmon-network
 
I have tightened the bolts, many were indeed a bit loose.
The temporary shutdown happened again todaywhen I forgot my laptop plugged in to the usband it went to sleep - so it looks like it is indeed the reason for the shutdown.

About the watchmon connection to the toolkit, I could not solve it with 2.0.7, so I rolled back to 1.0.31 and then it connectedfine. I will inquire to batrium about the issue.

Also I have reduced the charge controllerabsorption voltage to 3.42V, and it works well so far, the charger controller startsreducing the charging current only matching the loadwhen SoC is around 100%, and very little bypass is needed.

The voltage reading from the charge controller and the shunt always match very well, I have also checked that individual cell voltage from the watchmon match very well with the voltmeter. The cells are well balanced under small load (~0.1/0.2C) only under higherload the voltage reading differ, but usually it comes back quickly inline when there is no more load.
 
babish said:
I have tightened the bolts, many were indeed a bit loose.
The temporary shutdown happened again todaywhen I forgot my laptop plugged in to the usband it went to sleep - so it looks like it is indeed the reason for the shutdown.

About the watchmon connection to the toolkit, I could not solve it with 2.0.7, so I rolled back to 1.0.31 and then it connectedfine. I will inquire to batrium about the issue.

Also I have reduced the charge controllerabsorption voltage to 3.42V, and it works well so far, the charger controller startsreducing the charging current only matching the loadwhen SoC is around 100%, and very little bypass is needed.

The voltage reading from the charge controller and the shunt always match very well, I have also checked that individual cell voltage from the watchmon match very well with the voltmeter. The cells are well balanced under small load (~0.1/0.2C) only under higherload the voltage reading differ, but usually it comes back quickly inline when there is no more load.
Click to expand...
The loose bolts might have been letting the cellmons pull the voltage down too much eg joint resistance- so good thatyou tightened the bolts! :)

3.42 for LiFePo4 sounds about right. I have my LiFePo4 cells charging to 3.41V. There is a flat voltage "plateau" for LiFePo4& when the cell voltage starts rising fast, this is the SoC =100% point & you should look for that point & trim the voltages accordingly.Overcharging them beyond thisis bad, shortens cell life & can cause swelling (very bad).
 
Running USB at same time as the device is powered by battery will cause issues. going to sleap mode causes the USB port to go to a low power mode too and this will drop out the connection.

Highly recommend to have it powered and running only from battery and not USB (USB takes over....) Ie you need to sort the Wifi problem.
 
Please Please move the 2 rows of cells further apart. The cell mons look like they are overlapping the terminals or extremely close tothe other row in the picture. Its a disaster waiting to happen.
 
The cell mons do not touch though it is a bit tight (~2mm) where the second row starts, I will need to buy a longer connector to make more space there.

I tried again to update the toolkit to 2.0.7, I still cannot connect via usb, but it does work now via direct wifi (though sometimes it starts as if it is a new setting, eg there is no available daily history or it asks for a "Device sync").

But I still cannot update the firmware. Can it be done over wifi? Do I need an internet connection for the firmware update? or is it coming from the toolkit?
 
Suggestion: Contact Batrium Info for a session and let them help you with it.
 
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