Pity he hasn't installed and tested it yet.
Have you watched his Leaf upgrade video? I wouldn't want to be in a crash in that car.
Pity he hasn't installed and tested it yet.
There are loads of ANT BMS that will work with 16S, have bluetooth connection to an Android device to show voltages and could have the balancing turned off but they are expensive (especially if multiplied by 5 or 6) and would be overkill as they still have all the normal BMS options.arber333 wrote: ↑Thu Sep 02, 2021 11:05 am Right!
Yesterday i have measured my battery modules when i had to put them back in the car (after A/C system cleaning). I was really carefull with measuring voltage. I had 16S capacity active balancer connected for 3 weeks now. Some mixed results...
1. All cells within the 16S module were within 0.03V difference! That is a real plus.
2. Cells in modules not under active balancers had less than 0.1V difference with one or two exceptions that sank below 0.2V difference.
3. I noticed complete module that was actively balanced had lower voltage with 62.5V than not balanced which were around 62.8Vdc throughout the pack.
I can draw conclusion that within some margin active balancer draws some energy from module overtime although it keeps it aligned.
I bet using 6x active balancers for complete battery of 96S will rectify that.
Even if i will have each module balanced i will still use my BMS to show individual cell votages.
Does anyone know any BMS systems which would work directly with 16S modules and output CAN telegrams out? Only for information?
Hm... i am thinking of using Volt Gen1 BMS for 96S cells. Just like that. It is CAN bus controlled and it can transmitt cell voltages over CAN. With those active circuit i dont need other balancing.Alibro wrote: ↑Thu Sep 02, 2021 3:19 pm There are loads of ANT BMS that will work with 16S, have bluetooth connection to an Android device to show voltages and could have the balancing turned off but they are expensive (especially if multiplied by 5 or 6) and would be overkill as they still have all the normal BMS options.
Also it is difficult or impossible to have them all work on the one Android device.
It would be great if we could use an Arduino or mini PC of some kind to show the voltages of each cell and use some of these balancers to keep the pack balanced.
The one caveat about active balancers is they will mask the issue if a cell starts to go bad so it would be better if the balancing was only done once a week or maybe once a month.
I'm still living in hope I can use the Leaf BMS to monitor my system but haven't done anything about it yet.
If you are able to decipher the CAN signals and produce a display to show voltages then you are on a winner.arber333 wrote: ↑Thu Sep 02, 2021 3:33 pmHm... i am thinking of using Volt Gen1 BMS for 96S cells. Just like that. It is CAN bus controlled and it can transmitt cell voltages over CAN. With those active circuit i dont need other balancing.Alibro wrote: ↑Thu Sep 02, 2021 3:19 pm There are loads of ANT BMS that will work with 16S, have bluetooth connection to an Android device to show voltages and could have the balancing turned off but they are expensive (especially if multiplied by 5 or 6) and would be overkill as they still have all the normal BMS options.
Also it is difficult or impossible to have them all work on the one Android device.
It would be great if we could use an Arduino or mini PC of some kind to show the voltages of each cell and use some of these balancers to keep the pack balanced.
The one caveat about active balancers is they will mask the issue if a cell starts to go bad so it would be better if the balancing was only done once a week or maybe once a month.
I'm still living in hope I can use the Leaf BMS to monitor my system but haven't done anything about it yet.
This is my philosophy too. In OEM use and under warranty, I trust a BMS. In a cheap chinese BMS, or my own DIY efforts, I do not. Especially considering the alternative.arber333 wrote: ↑Thu Sep 02, 2021 4:06 pmI like active balansers very much. But i dont trust them fully. I need to have a system that can detect individual cell voltages and display that over CAN. Then i can teach my car controler (charging, DCDC.. ) to gather cell values and report anomalies. As a kind of monitor.
I allready made my share of tiny voltmeters. I put them here viewtopic.php?f=13&t=61MattsAwesomeStuff wrote: ↑Fri Sep 03, 2021 12:09 am But, I don't know of a BMS that is reporting-based only. I don't need CAN, as I'm not likely to have a central CAN system anyway, but, I'm not opposed to it. I would ideally just like something cheap as possible that gives me the information I need and lets me decide what to do about it.
I've even considered hooking up a grid of 96 tiny voltmeters on a panel and a cannon plug that I shove in once in a while to check voltages. (Or a 5x2 grid I move to 10 different terminals).
I like this a lot.arber333 wrote: ↑Sun Sep 05, 2021 11:34 am I got those remaining 5 boards from Aliexpress. That was fast shipping.
For now i reconfigured my existing BMS so it is connected to active balancers by 16S connection. I left 1.6mm holes for testing and measuring cell voltages and they accepted the new balancer cables.
20210904_192301.jpg
I didnt want to shorten the cables so i kept the lenght and i sorted them out along the circuit.
20210904_192314.jpg20210904_192332.jpg
What i found out when i measured my cells was the small but consistent drag from those balancers. In the pack that was connected to the first 16S balancer couple of weeks before i noticed voltage 4.02V per cell in all cells! While others were varying at 4.02 to 4.08...
I think rest of cells will come in line when they accept balancers.
So for me those capacitive active balancers are a real deal!
The only think left to experiment with is the small pads on the balancers which are soldered by default. If i cut ithis connection balancer stops. I am thinking of connecting those pads with opto couplers and a signal from my BMS. This will operate balancers only above certain voltage where Ri is high enough that balancing (charg or drain) actually matters.
20210904_192327.jpg
The idea is to have a central system which would transmitt cell values to compare on a single LCD or similar. I am inclined to use Ampera/Volt BICMs since they are already designed for this application and they work using SimpBMS with LCD.