It can be that simple, just remember the Sleep mode in addition to powering down the CAN bus and devices, it also powers down the HV and LV circuits so You need to wait until the charging is done.
I had also posted how to use relays to put the Zeva automatically on sleep mode when the KSI switch is OFF and the charger AC is not plugged in.
My simple BMS does not drag down my pack voltage like that. I unplug the charger control relay cable while the cart is sitting idle. The pack voltage is 58.5V after the charger turns itself off. It takes weeks to drop one tenth of a volt when I don't use it.
When you say I would need to wait until charging is done, are you saying I would control the sleep function and not the BMS itself? Would I need to install a SPST switch inline with the ground to control this function?
Looking at the manual, it states the BMS continues to monitor cell voltage in sleep mode and will disable the BMS if cell voltages drop below minimum threshold. So, if I were to put the BMS to sleep within 10 minutes of completing a charge it wouldn't continue to shunt voltages to keep cells balanced?
The only way it can consume less power is to stop most of the processing, which includes the cell balancing function.
The BMS itself is not the power hungry device, most of it is from the display which will use about 2AH/day depending on the active screen and back lighting.
A simple on/off (SPST) switch will do for activating the "sleep" mode.
If You don't want to wait the 1 hour "balancing" period after the charging is done, you can always look at the cell voltages after the charging is done, flip the "sleep" switch ON (connect the sleep pin to negative) and later when you wake the BMS check to see if the voltages balanced.
I think I'll try it out like that (with the SPST) because my cells stay fairly close (within hundredths of a volt) and keep an eye on it and if need be I'll have to just always remember to give it an hour after charging before activating sleep.
I can't recall all of the details of hooking up the sleep mode, but I may add a simple on\off switch of the batteries when it will sit for a long period of time.
As of today.....day 4 after a full charge....then let it sit a day, I lost .3V on day one and .2V per day on day 2 & 3.
Just run a wire from the sleep terminal to a switch and from the switch to the battery negative.
Turn the switch ON so the sleep terminal is connected to negative, that is it.
It appears that my BMS & monitor drags about .1 to .2-V per day just sitting there.
I'm going to pick up a switch and connect the sleep mode as you suggest.
So I checked my voltage tonight and it was 54.1v. That's a 3.7v drop in 7 days without driving the cart.
I enabled the sleep function tonight and I'll check how much of a drop I see over the next week.