You have to realize that once you get in the high charge area that very little energy can make the cells go way out of whack. Your strategy to stay below 98% is probably best. Personally I only start balancing above 90% capacity as its pretty much useless to try and balance the large amounts of energy in the cells below that.If I lower the balance voltage threshold, it will exacerbate the issue. below 98% charge, my balance is <20mV.
Probably, I should just leave it and just not charge to the top. I don't need to eek out any extra capacity.
Thank you,
Doug
OK. Seems like we are on the same page. That's why I set the balance threshold so high. But since I have one cell low and the 3 high, it seems there is a lot of energy to give off.You have to realize that once you get in the high charge area that very little energy can make the cells go way out of whack. Your strategy to stay below 98% is probably best. Personally I only start balancing above 90% capacity as its pretty much useless to try and balance the large amounts of energy in the cells below that.
I think that with bigger cells, that top 5% is where you'll get the most fluctuations like the others have said. I think that generally between 3.5 to 3.65 is the "zone" from consensus. By that time too, charging amps "should" be getting much lower due to resistance changes which affects the cell's charge rates. You have a "12V/280AH" pack, assuming you want to save %5 at the Top & Bottom giving you 90% pack capacity (*1) Then you'd likely want to set your High Volt to 13.87 (3.45v per cell) Low Volt to 10.5v (2.62 per cell)@Steve_S - thanks for the info!! I'd consider adding a fan. But probably won't. I think I'll just charge to a slightly lower SOC and call it good. The issue only comes up @ >98% SOC.
I don't need to eek out that last bit of capacity.
Doug
I would reinstall the software and or try to reset factory defaults
I'm not sure if it's going to make any difference, but I did notice that your LCD is at version 4.0 ..... not the new 4.01.
If you are building your setup as Common-Port then yes, you only need one DCC Contactor.
Yes, the Low Temp function was added into the firmware this spring and it does work as expected. Charging will be disabled if the temps are too low or too high obviously. With a Single DCC is "should " still allow for discharging (LFP can discharge up to -20C temps generally), some lower, depends on specific cell chemistry, Always refer to Cell Manufacturer Documents for your specific cells.
Chargery BMS, DCC (Solid State Contactor) thread.
Good Day folks, I am starting this thread related to the Chargery DCC, so the first post will be a basic "intro". See the following posts for more info. The DC contactor is designed specially to work with the CHARGERY BMS', the following are some features: Bi-directional connection, one...diysolarforum.com
I cant diagram for sure but as I see it there is actually 2 directional switches , for lack of better term, inside the dcc one to shut off input and one to shut off output.@Steve_S .... Sorry, but I can't get my head around this ... could you please do a diagram that shows how a single DCC would cut of charging but still allow load? Seems to me that 2 SSR's would be required to do that .... or does one DCC have 2 SSR's?
That's the approach I'm taking .... trying to avoid switching the battery power.I cant diagram for sure but as I see it there is actually 2 directional switches , for lack of better term, inside the dcc one to shut off input and one to shut off output.
But in all honesty I am a skeptic as to how well these will work. I have some on order but do not recommend them as of yet. Personally I do not like the idea of shutting off the connection between the inverter and SCC from battery I would rather shut the device down, use a device that takes 12v input from the Chargery or shut down the between the panels and SCC or inverter and load since the amps at those two points are the least. Even though I am not afraid to shut down SCC with panels attached. I do not think it is a good Idea to have it boot up every time there is an overcharged cell.