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Oh no, Another JK BMS Question... Settings, Calibrations, and SOC!

dfwbmw

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Sep 3, 2023
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DFW
I have a B2A8S20P-Heat and CAN and everything is working great. I tested every cell (cheap $97 a cell 280AH free shipping aliexpress DIANKAISHOU Battery Supply Store) and they all pulled 293 or so amp hours, top balanced them, put it all together and balance was maybe off by 2 mil-volts occasionally, most of the time delta 000. Did full charge to OVP cut off of 3.61, then did a full discharge to 2.55. Did volts and AH calibrations at various times and my SOC is spot on. SOC is so good right now I think I might not run a separate shunt and use the 4 inch screen inside the rv. I know it will drift but I do get full charges kind of regularly with a lithium charger/converter in the rv. Now the questions....

Since it's an RV can I used the JK BMS on and off switch (long press to turn off) to turn off the battery when in storage? Since I went to lithium (100ah now) I usually only plug it in the day before I go and always come back with it down about 20 to 30 percent from full in preperation for it sitting idle. The chassis battery is plugged into a different lead acid charger.

If I decide to use this switch to turn it off, will it loose any settings, calibrations, and most important my highly coveted SOC perfection?

I have a 2000 watt Renogy inverter hooked up to it with a separate automatic transfer switch so I can watch movies on tv with the Rapsberry PI (165 watts), run an automatic drip coffee maker (700 watts). and presto skillet for making bacon on the outside plug (1500 watts). Not all at the same time of course. I did torture test it with a constant 1800 watts for 45 minutes before I put the battery in its case, connections, crimps, bus bars stayed cool and only topped out at about 5 degrees above room temp. Full pack pulled 289 AH.

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Since it's an RV can I used the JK BMS on and off switch (long press to turn off) to turn off the battery when in storage?
Yes, this is fine. Turn loads off first, preferably.
If I decide to use this switch to turn it off, will it loose any settings, calibrations, and most important my highly coveted SOC perfection?
You won’t lose any settings. I’m unsure about the SoC, but I believe it defaults back to whatever it was before the battery was turned off. But this shouldn’t be an issue if you’re going to plug in to recharge before you leave for a trip. If you get to 100% it’ll be correct.
 
Thanks I think I will run it like that and not mess with a master switch I have.
 
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