Optimal DoD for Li-ion cells?

[lctorana]

What is the optimal depth-of-discharge to maximise the longevity of my Li-ion cells?

Is it shallow, like SLAs?
Or should I aim to flatten them every time, like NiCads?

Or is it the inievitable somewhere in between?

 

[DM51]

If you keep them in the range 20% (3.7v resting voltage) to 90% (4.15v resting voltage) you will get the best life out of them. You can charge them at any stage without detriment - there is no 'memory effect' with Li-Ions, and shallow discharges are actually good for them.

Charge and discharge rates will also have an effect on cycle life.