So I have a 18700 Xtar that is a little over a year old that while sitting on a shelf will self-discharge roughly .2 volts in about 30 days. I have several cheaper batteries that hold up better than this.
Does this amount of discharge sound a bit excessive? It charges just fine on my WP2 right up to 4.12v, no extra heat or anything
If the protection circuit was draining that fast, there is something wrong with it. They should have a parasitic drain of under 10uA. A 2600mA cell would take almost 30 years to drain. In fact a good cell itself would self drain faster than that.
My concern would not be capacity; rather if the circuit is self-draining like that, is it still actively ‘protecting’ the cell?