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Overkill / jbd PCB limiting SOC

I just have the Aili shunt, it is reading the exact same SOC as the BMS.

I just noticed there is a custom setting for the enerdrive charger.

Pg. 11

Would that be appropriate to drop it to 13.8 absorption and float 13.4. any chance that will stop it charging over a week?

I'm surprised there isn't a simpler way of doing this to maintain loads while maintaining and healthy SOC for longevity. Changing the charge profiles all the time is a bit of a hassle ?
Yes, those voltage settings would be appropriate, very similar to what I do. If you don't get the results you want, you can adjust the absorb up or down as necessary.

@fhorst
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To my knowledge there aren't BMS available yet that you can program to cycle between 85-90% SOC for 14 days (or 1/2/3/6 months) and go to 100% SOC for a week or whatever, depending on how you like.
Or better, go to the 85-90% profile when all the cells have reached 3.6v twice."

Something just occurred to me. You _can_ (probably) do this in Victron controllers(sort of). Victron controllers have an automatic equalization mode that will run every 30 days. For LFP, equalization is wisely turned off. But all the parameters are adjustable. There isn't any reason you can't set the EQ voltage to 3.65V per cell, and use it to fully charge the pack once per month. If I recall, EQ terminates either on a timer or on tail current. These would need to be set appropriately, but should otherwise work to automate a balance and resync charge. I might play with this. (manually triggering the EQ so I can watch it instead of it happening when I am not around)
 
Victron VE.Direct MPPT should be able to do this with custom messages being sent from Arduino program or computer program.

Messages must be in HEX format to edit values if memory accurate.

Should be possible to write tiny program in arduino that uses GPS date or something, with an EEPROM to store the last update.. send HEX formatted messages that alter charge voltages.
 
System 2p16s Lishen 3.2v 272ah (Basen Emily Peng). Took a long time to arrive while I sweated. All at 3.29V.
I connected an Overkill 100A 48v BMS. Left on panels (2kw max for 2-3 days. Overkill has the greatest warranty I have ever seen! I use the bMS as a charge controller and seems good. I cannot say enough about this controller. Many many adjustable settings and a graphic on voltage, current andcapacity over time. Since this is my first and only BMS there might be better. Bluetooth just extends the length of my house.
So far batteries down to about 55% overnight. 90% max. Using SOC chart from this site. Main load is the Fridge, about 200W
and runs a lot.
Renogy 60A controller into BMS. Made no changes to the controller which is set to my old FLA batteries.
Redrock rd Nevada.

What do you think?

Cheers, Lew
 
System 2p16s Lishen 3.2v 272ah (Basen Emily Peng). Took a long time to arrive while I sweated. All at 3.29V.
I connected an Overkill 100A 48v BMS. Left on panels (2kw max for 2-3 days. Overkill has the greatest warranty I have ever seen! I use the bMS as a charge controller and seems good. I cannot say enough about this controller. Many many adjustable settings and a graphic on voltage, current andcapacity over time. Since this is my first and only BMS there might be better. Bluetooth just extends the length of my house.
So far batteries down to about 55% overnight. 90% max. Using SOC chart from this site. Main load is the Fridge, about 200W
and runs a lot.
Renogy 60A controller into BMS. Made no changes to the controller which is set to my old FLA batteries.
Redrock rd Nevada.

What do you think?

Cheers, Lew
Have you changed any of the values in the Overkill? IIRC, the default values are on the high side, well over 3.65V per cell. The reasoning being that the BMS should not cut off charging, the charge controller should. So only if the charging had a malfunction would the BMS disconnect. At the very least, you should check that. As is you likely could overcharge the battery.

You should also set the bulk/absorb voltage in the Renogy to 3.5V - 3.65V per cell, and the float to 3.375V (or anything less than 3.4V) per cell.
 
This might sound stupid but I have come up with a mini hack which works perfectly so far.

I charged the battery up to 80% SOC. Then while I was charging I disabled the charge and discharge in the BMS. I can then run my loads (fridges/freezers full of food and beer)off AC or solar while I'm away.

Whilst not changing any settings, good thing is I just turn the bms back on before I leave for the trip and she will fill right up for use for the time I spend away.

I'm happy with that for now ???
 
Wholeybee,
Good to know. I have messed with many many setting over several days. First I cut back the cell and pack values to way conservative values then slowly increasing as I became more confidant. New batteries and did not want to f them up. Again, this overkill bms is awesome!
I did see a cell way over the limit and checked with a vom the real cell voltage. It was nominal. I think the cell to cell conections are causing this disparity. Since the cell voltage is within my limits I will look further when I get arpund to it.. I need to get better cel to cell connections since I used up a lot of bussbars from the shipment making parallel connections.
Today is a crap Sun day and the pack is almost to 50% capacity. This is a monumental improvement over my old Crown fla's.
Later, Lew
 
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