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Chargery BMS now with Low Temp Cutoff

Hello

Has anyone connected to the com3 port on these and seen what it spits out on a computer? The connection would be fairly simple, an RS232 connection to USB adapter is all that is needed, connect black to gnd and red to RX (the chargery is doing the transmitting, the RS232 to usb adapter is the reciever). A terminal program like Putty (Windows) or SerialTools (Mac OS) could then be used to see the data, provided you set the correct comport on the program.

Reason I ask, is that I would like to hook a BMS8T to a 8 pack of cells as the bms, and send the SOC and other data to the Raspberry Pi running Victrons Venus OS. This in turn would then command the inverter to shut down (if the battery was getting low) or tell the charge controller to throttle back (during TOC balancing) or stop when the battery is full.

I have connected the Chargery BMS to my Venus GX and created a serial driver at the Venux box. Additionally, I have embedded the data to the Venus GX remote interface. Since I do not know if i am loowed to link directly, you can find a little more information victron energy community page. Just search for "VENUS GX receive data from external RS232 interface".

I am looking forward to share my code. But this is not that easy as it seems and I need to make some things simpler. Anyway, if you have any questions I can try to help you. First important notice: The TX signal is inverted and I need to programme my USB FT232 USB adapter to be able to read any data.


Bye
Tobi
 
@Craig & @martan If one of them fails can you open it and take pictures of the inside? I'm curious to see how they're made and what they used as the switch components.
 
I ordered my Chargery BMS system from Jason directly on March 5, 2020. It just arrived today, March 13. I would call that record time, wouldnt you? I want to openly commend Jason and Chargery for being one of the most professional companies I have ever had dealings with. He answered every one of my questions in a precise and timely fashion. I would not hesitate to recommend Chargery to anyone in this forum.
 
I found this relay which has a holding current of only 0.13A. Would this work with the BMS? Sounds too good to be true
The part number shows that it requires an "external economizer"( likely a RC network) but the pics show a positive and a negative post. Hmmm
 
Hello



I have connected the Chargery BMS to my Venus GX and created a serial driver at the Venux box. Additionally, I have embedded the data to the Venus GX remote interface. Since I do not know if i am loowed to link directly, you can find a little more information victron energy community page. Just search for "VENUS GX receive data from external RS232 interface".

I am looking forward to share my code. But this is not that easy as it seems and I need to make some things simpler. Anyway, if you have any questions I can try to help you. First important notice: The TX signal is inverted and I need to programme my USB FT232 USB adapter to be able to read any data.


Bye
Tobi

Sounds simple enough, just import your code, and add it to serial starter to make it go? (and possibly give the FTDI cable dedicated to it a unique ID_Model using FT_Prog and while there, invert the RXD line).

I have written scripts that automate most of this stuff when an update occurs so it isn't lost. I have also set my pi to not update unless I tell it to, so I don't loose VRM portal access should an update occur if I am away.
 
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Sorry, I cannot recommend any low power relays. There is a huge variety of them and his subject has been discussed in other threads with folks making recommendations for Known Good Relays that will do the job. ATM, I am using the relays supplied by Chargery but watching closely.
Thanks
 
I had assumed the BMS would arrive with up to date firmware.
my new version doesn’t have minimum temp cutoff.
so to unlock that functionality I have to update both UI and Main firmware, right?
And there is no Mac version of the updater?
Is there any way to update besides windows machine?
In my config I can’t separate charge and discharge loads (my inverter is also a charger)
Some future F/W update should have control setup for just one relay.

For now I plan to use the load and charge side with one Bosch cube relay where that one will cutoff the trigger side of the main contactor. Downside of this is all conditions must be met to charge or discharge.
I’m using gigavac gv200 with economizer circuit. it is working fine.
 
In addition to my above questions .... can anyone please explain the time delay in the main config screen? I had assumed this was for a startup load on a motor or similar. But then I read about the delay board and was trying to understand the difference.
 
I had assumed the BMS would arrive with up to date firmware.
my new version doesn’t have minimum temp cutoff.
so to unlock that functionality I have to update both UI and Main firmware, right?
And there is no Mac version of the updater?
Is there any way to update besides windows machine?
In my config I can’t separate charge and discharge loads (my inverter is also a charger)
Some future F/W update should have control setup for just one relay.

For now I plan to use the load and charge side with one Bosch cube relay where that one will cutoff the trigger side of the main contactor. Downside of this is all conditions must be met to charge or discharge.
I’m using gigavac gv200 with economizer circuit. it is working fine.
I don't think there Is a version of the updater software for Apple, I'm not sure if any emulator will do either. Sorry, no help there, maybe a question you could ask Jason about. The Low Temp stuff is in the firmware update.

The delay board to enable an extended delay of 2 or 3 seconds between the BMS & Relays, used for high surge moments and such, typically in EV applications or when one knows here will be big surge spikes. I got the delay boards for the "Just in Case" situation if they are / were needed, figuring I sure as heck would not want to wait 2 weeks or more for a $4 part if my system needed it. Nothing worse than being held up and at a standstill in a project over one stupid piece, that really irritates me, as I think it does to most others too.
 
On an apple computer just download the free windows 10 iso, and use bootcamp. You don't need to put in a license key, and you can remove the windows 10 installation once your done flashing the BMS. I do this quite often with my MBP 2018 model.

The only other option is to brrow a windows 10 laptop specifically for the purpose. I wouldn't trust the hardware/software layer of Parallels or VMWare when it comes to flashing hardware.
 
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Hi Guys,
Thanks a bunch for the replies. I will track down a friend with windows.
doesn’t make sense to me that they didn’t come updated. But ok. I’m in no danger of freezing here in southern Cal, so not at all urgent.

The configurable delay feature can be adjusted to 60 seconds ( I think). I set mine for 15 seconds thinking this would easily address inverter demand for starting up microwave or air compressor motor or leveling jack pumps.

why would 2 or 3 seconds extra make a difference?
Or does the feature not work without the board?
I’m clearly missing something!
Cheers, Doug
 
One has to remember that when they do a production run, it's for hundreds if not thousands of units at the time. During that run, they will install the current software at that date, if the software is updated after production, then yes it has to be updated. It is unrealistic for a company to open all the pallets with packed boxes / cases to update each piece of equipment. I suppose you could ask them to do it for you but they'd likely charge for it as it does take time to do.

The Delay Board is an option and is an addition on top of. A video was posed earlier about hooking up the BMS to Leaf Cells, that also discusses the Delay Board and it's application. In fact it was developed for the EV side with the help of the person who did that video.
 
Hi Steve,
How do you setup your delay for your off grid cabin?
I think yours might be similar to mine since my camper is a mini cabin.
Thanks again for all of the info!

doug
 
I got it "just in case" and haven't needed it, but I have it should Murphy's Laws get applied and I end up needing them. At the end of my project (current battery one anyways), I'll have 4 BMS', 8 relays and POS & NEG bus lines and am hoping I won't need them, I somehow doubt that I will as I have nothing that is crazy high in draw. Seriously, my deep well pump, nukelator & most importantly coffee maker are the "heavies" and none of them pull that much.... If ALL of them were on at once, I'd be pulling around 200A and my well pump is soft-start so no big haul of juice needed on startup.

BTW: You can likely pickup a working Win-10 Lappie from a pawnshop or so for $50 bucks. It doesn't have to be anything special or heavy duty, really a seriously cheapo used lappie would serve... heck you could adapt it to be a monitoring system too if you wanted too. Maybe even off craigslist or something similar.... Heck, you may even have a buddy who has an old in stuffed in the bottom of a closet somewhere. Win-7 or 10 and your good to go.
 
To clarify: the delay feature works without the board right? That is just for additional delay?
Sounds like you have a nice setup and more than you need!
But your sun harvest might not be as high as other areas.
thank you again,
Doug
 
Yes, works without but is limited to the BMS settings.
I'll have 21.5 kWh of LFP and am doubling my 2kw solar panels to 4kw. Fixed ground mount @ 45 Degrees. NOT The best in December I'll tell ya. FINE right now though... I am up north so... look up Algonquin Park Ontario to get an idea of where I am... it's just a couple of klicks from me. The Bears are AWAKE already month and a half too soon.
 
OK. thanks a bunch. The delay is on any trigger which would turn off either relay, right? (temp, low / high / difference voltage, etc.)? Are you turning yours off to start?

One more question: what is a normal cell voltage difference? Just for grins, I setup the BMS to balance in storage mode. They haven't changed much. Maybe a few mV. But things bounce around. I'm in the range of 10mV to 18mV. Sort of thinking I'd need a week to seek if it is really doing anything. I also see the range is as low as 8mV. So, I guess close to the bottom of the range must be pretty decent.

+ I do notice the BMS reports different voltages than my Fluke. Not by much, but a few mV. And then a bit more on the whole pack (of course).

I'm not obsessing here, just curious. I'm used to AGMs and other batteries, not LFP.
 
The relay is designed to precharge any high current loads such as an inverter or a motor. When the BMS turns on the load relay it will close the small load relay which should have a resister in series with the load and after the delay value it closes the main load relay and opens the small load relay. This way you can precharge the inverter before closing the main power relay. Look at page 26 of the manual.
 
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