Why do we stop discharge of 18650s at 3.3 volts? I’ve been looking at spec sheets and it shows the cut off voltage to be 2.5. Is there a reason why we don’t let them go below 3.3v? I’m specifically talking about the 30q.
People usually set cuoff at 3v a cell.
3.3v people usually recommend for lipo’s
I like to set my pack cutoff for 2.8v a cell, 28v for a 10s pack.
Take a look here on how the voltage behaves in respect to the capacity
https://lygte-info.dk/review/batteries2012/Samsung%20INR18650-30Q%203000mAh%20(Pink)%20UK.html
3.3 V you are leaving energy unused and will notice more current limit as it approach that value
If yourself it to start at 3 V and end at 2.9 V, even at full current you will get most of the energy out and only feel the power reduction at the really bottom of the capacity
Every cell is different, you have to look at the discharge diagrams and find good values from there
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So realistically I could drain 30q batteries to 2.5v but it would be pointless to drain it that low. If that’s true o guess that extra .5v gives a good cushion for cells that discharge unevenly
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Yeah, there is almost no capacity, and small differences in capacity from cell to cell become apparent at that low voltage, if you using a BMS just for charging, one cell could go down well bellow 2.5 V
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