SlimyLemur56
New Member
- Joined
- Feb 20, 2020
- Messages
- 27
I have a 4S 12v 120AH battery and I have some questions about configuring my daly smart bms for the first time. I have not yet done a charge cycle through the BMS if that puts any meaningful context behind my questions.
1. About sleep timeout
I was initially concerned that it seemed the bluetooth would time out and shut itself off until I reset the BMS by pressing the button. I've seen in a few threads you can fix this by setting the sleep time to either 15300 or 65535 (seems to be anyones guess which will work so I'll try both). But I also saw someone say that it comes back on when you put a load on the battery and start drawing current. Is this true? In which case the only reason turning off the sleep timer is so bluetooth always works even when the thing is sitting in storage?
I've built my battery into a mobile case and I don't want to have to open the case and press the button every time I want to check the SOC/balance, so I would disable the sleep timer, except if bluetooth will come back on any time it's in use, that would solve the problem in itself and possibly reduce the BMS drain while resting.
2. About rated capacity
My understanding is I should do a drain test and test the capacity and set it to the results of that test rather than what it's actually nominally rated for. Is that right?
I plan to use some more gentle voltage limits like 13.4 charged and 11+v discharge limit. For (specifically) the capacity test to get the AH for the "rated capacity" setting, should I leave those settings on their "full values" like 14.6-10v? Or should I enter the capacity mesaured within the limits I intend to actually use in practice?
3. About low temperature cutoff
Much is said about not charging at extremely low temperatures. That is not an issue for me as I will never charge this outdoors and can set a "Chg low temp protect" far above 0C, even around 10-15C if I wanted and it should never become relevant.
But I'm curious about "disChg low temp protect", my understanding is that discharging in the cold is less dangerous than charging in the cold, but surely there is still some safety constraints. I would like to (very occasionally) use the battery outside in some lets say "Texas-cold" temperatures so maybe (in the most rare extreme hypothetical) around 0C or -4C. Is it safe to set the "disChg low temp protect" a few degrees below that, say -6C?
1. About sleep timeout
I was initially concerned that it seemed the bluetooth would time out and shut itself off until I reset the BMS by pressing the button. I've seen in a few threads you can fix this by setting the sleep time to either 15300 or 65535 (seems to be anyones guess which will work so I'll try both). But I also saw someone say that it comes back on when you put a load on the battery and start drawing current. Is this true? In which case the only reason turning off the sleep timer is so bluetooth always works even when the thing is sitting in storage?
I've built my battery into a mobile case and I don't want to have to open the case and press the button every time I want to check the SOC/balance, so I would disable the sleep timer, except if bluetooth will come back on any time it's in use, that would solve the problem in itself and possibly reduce the BMS drain while resting.
2. About rated capacity
My understanding is I should do a drain test and test the capacity and set it to the results of that test rather than what it's actually nominally rated for. Is that right?
I plan to use some more gentle voltage limits like 13.4 charged and 11+v discharge limit. For (specifically) the capacity test to get the AH for the "rated capacity" setting, should I leave those settings on their "full values" like 14.6-10v? Or should I enter the capacity mesaured within the limits I intend to actually use in practice?
3. About low temperature cutoff
Much is said about not charging at extremely low temperatures. That is not an issue for me as I will never charge this outdoors and can set a "Chg low temp protect" far above 0C, even around 10-15C if I wanted and it should never become relevant.
But I'm curious about "disChg low temp protect", my understanding is that discharging in the cold is less dangerous than charging in the cold, but surely there is still some safety constraints. I would like to (very occasionally) use the battery outside in some lets say "Texas-cold" temperatures so maybe (in the most rare extreme hypothetical) around 0C or -4C. Is it safe to set the "disChg low temp protect" a few degrees below that, say -6C?
