Chargery BMS now with Low Temp Cutoff
- Thread starter Steve_S
- Start date
Hello,
as promised the source of Chargery BMS driver for the Venus OS devices: https://github.com/Tobi177/venus-chargerybms
I will add more documentation if I will find more time.
Bye
Tobi
as promised the source of Chargery BMS driver for the Venus OS devices: https://github.com/Tobi177/venus-chargerybms
I will add more documentation if I will find more time.
Bye
Tobi
Very Nice!
I use a raspberry pi with this USR IOT rs232 to ethernet converter. I am willing to share code and make some instructions. Im not so good at Videos lol
Bob B
Emperor Of Solar
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- Sep 21, 2019
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- 8,630
Thanks Craig ... I think you are already pretty busy doing things to help people on this forum ...... but any info you can provide would be welcome. Maybe even some good learning links.
I've been wanting to get into Raspberry Pi and Arduino. With a quick look at Arduino, it looks VERY similar to other control software I have used. I don't want to sidetrack this thread too bad .... maybe there could be another thread on "Chargery BMS communications" with a link to it on here.
bostonbuzz
New Member
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- Jan 13, 2020
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- 52
Are you sure that wiring up the bluesea to the chargery will have it operate with the chargery correctly (powered and closed, no power and open)? If so I’ll get one.
I'm confused because I read their documentation stating you just need to kill 12V+ to the control side to kill the battery connect.
My concern would be if you need to disconnect the ground, how would the Chargery then protect the battery if one or more of the battery disconnect triggers is met? Then you'd need to ensure both positive and ground were disconnected in such an event(s).
Doug
Doug, your confusion may arise from the particular situation I am seeking to resolve. I leave my boat unattended for extended periods of time, either exterior covered or in indoor winter storage for instance, during which time my batteries (and their BMSs) are turned off and no solar is available to charge them. With lfps, leaving them 50% discharged is optimum. I'm interested in removing any parasitic loads which might drain any of my batteries over this long term. In this case, it means making sure the BMSs as well as the 7713s (and any similar devices) are completely turned off. I know 13mA/7713 is quite small but, in my instance, is not the only such parasitic load which might be left on to drain the batteries while their respective BMSs are shut down.
In normal operation, I've plenty of solar and/or dockside charging available, and many larger parasitic loads are lost in the noise of daily use.
In normal operation, I've plenty of solar and/or dockside charging available, and many larger parasitic loads are lost in the noise of daily use.
I relate well, I have the same scenario with my camper.
It sits unattended and totally moth-balled for weeks or even a month or two, also. And under a car-port type cover, so no solar to recharge. So my batteries are completely disconnected.
I plan to leave LFP @ 13.2-ish. But 13.1 to 13.3 should be 30% to 70%. According to the CEO of Battleborn, they aren't concerned at what SOC it is left, as long as it isn't terribly low. So, I don't plan to be too picky as long as I'm in that window.
I think you saw the circuit diagram I created in another thread. I interrupt the ground of control side of the heavy duty contactor relay with a manual switch. That manually disables the relay and eliminates any charge or load. Then, I put the BMS in sleep mode (red STOP button).
I've left for a week and taken photos of the Chargery voltage screen before and after. The pack voltage actually went up by 20mV, I guess since it was at rest for a while.
Jason from Chargery said the draw was 5mA in sleep mode. So, I can't leave it indefinitely.
My total parasitic load when the battery active is around 140mA to 150mA. So 3-4 Ah / day. My solar is 900W (max), so I figure this is pretty nominal. This translates to maybe 200Ah to 300Ah total collected.
You could get the parasitic down with an SSR - only based solution. I'm only using one SSR and a Gigavac GV200M (documented 130mA draw.)
Obviously, your numbers and sensitivity to acceptable parasitic load may vary.
Cheers,
Doug
It sits unattended and totally moth-balled for weeks or even a month or two, also. And under a car-port type cover, so no solar to recharge. So my batteries are completely disconnected.
I plan to leave LFP @ 13.2-ish. But 13.1 to 13.3 should be 30% to 70%. According to the CEO of Battleborn, they aren't concerned at what SOC it is left, as long as it isn't terribly low. So, I don't plan to be too picky as long as I'm in that window.
I think you saw the circuit diagram I created in another thread. I interrupt the ground of control side of the heavy duty contactor relay with a manual switch. That manually disables the relay and eliminates any charge or load. Then, I put the BMS in sleep mode (red STOP button).
I've left for a week and taken photos of the Chargery voltage screen before and after. The pack voltage actually went up by 20mV, I guess since it was at rest for a while.
Jason from Chargery said the draw was 5mA in sleep mode. So, I can't leave it indefinitely.
My total parasitic load when the battery active is around 140mA to 150mA. So 3-4 Ah / day. My solar is 900W (max), so I figure this is pretty nominal. This translates to maybe 200Ah to 300Ah total collected.
You could get the parasitic down with an SSR - only based solution. I'm only using one SSR and a Gigavac GV200M (documented 130mA draw.)
Obviously, your numbers and sensitivity to acceptable parasitic load may vary.
Cheers,
Doug
Had a few Chargery BMS tuning questions - realize these are application specific.
(Note, my normal loads are in the neighborhood of 0.02C to 0.04C. Very low. Maybe 15 to 30 minutes / day they'll hit 0.5C or .6C and even then they'd most likely be broken up. 95% of charge energy will be from solar and might hit 0.2C at mid-day full sun.)
1. Can anyone here offer setup suggestions for cell voltage differential on a 4S 280Ah pack?
I set mine for 75mV. I saw 40mV delta during a sustained 150amp draw @ 50% to 60% SOC. At steady state, my cells are within 10mV. I poked around this site for recommendation, but didn't see much.
2. Seems like greater V differential tracks C - rate? Does it change closer to the knees?
3. How do you setup your time delay for events which disable the pack? I have mine set for 15 seconds. I figured this would accommodate a surge load by my 2800W inverter. Is this too long?
4. How about safe temp delta (I'm using F)? So far, I have yet to see more than 1F.
Thanks!
(Note, my normal loads are in the neighborhood of 0.02C to 0.04C. Very low. Maybe 15 to 30 minutes / day they'll hit 0.5C or .6C and even then they'd most likely be broken up. 95% of charge energy will be from solar and might hit 0.2C at mid-day full sun.)
1. Can anyone here offer setup suggestions for cell voltage differential on a 4S 280Ah pack?
I set mine for 75mV. I saw 40mV delta during a sustained 150amp draw @ 50% to 60% SOC. At steady state, my cells are within 10mV. I poked around this site for recommendation, but didn't see much.
2. Seems like greater V differential tracks C - rate? Does it change closer to the knees?
3. How do you setup your time delay for events which disable the pack? I have mine set for 15 seconds. I figured this would accommodate a surge load by my 2800W inverter. Is this too long?
4. How about safe temp delta (I'm using F)? So far, I have yet to see more than 1F.
Thanks!
Pierre
Somewhere down South
- Joined
- Dec 21, 2019
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- 1,125
Must have driven near / past your home during a recent visit to the park ! Lovely part of CA.
This isn't necessarily a Chargery question maybe move it to general BMS advice. I don't use those batteries so I can't properly answer
Steve, what is the name of your Youtube site?
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
That is one of Will's videos. I do NOT do YouTube or Faceblot etc...
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
The New VERSION 3.04 of the Chargery Manuals are NOW AVAILABLE - April 4, 2020
LINK : http://chargery.com/spec.asp
LINK : http://chargery.com/spec.asp
Thank you Steve!
Just a couple questions if you don't mind.
The 4s+4s interests me as I'm looking to stay 12v. In this case I'm assuming both batteries would be protected behind the same pair of relays but they would have better monitoring and balancing vs a single 2p4s battery layout?
Is external power really required on a 2p4s or 4s+4s battery? Is the 12v not enough?
Thanks again for your time and efforts working on these manuals.
Just a couple questions if you don't mind.
The 4s+4s interests me as I'm looking to stay 12v. In this case I'm assuming both batteries would be protected behind the same pair of relays but they would have better monitoring and balancing vs a single 2p4s battery layout?
Is external power really required on a 2p4s or 4s+4s battery? Is the 12v not enough?
Thanks again for your time and efforts working on these manuals.
Last edited:
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
12V is not enough for the BMS as indicated in the doc's, 15-30V @ 3A is what the BMS needs.
Are you sure about that? I have mine connected only through the balance cables and it turns on. I haven't checked if it has enough juice to power the relais though
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