I've occasionally discharged my NiMH batteries low enough that my LaCrosse charger decides it's a dead cell. But shorting the positive terminal with a working

I've occasionally discharged my NiMH batteries low enough that my LaCrosse charger decides it's a dead cell. But shorting the positive terminal with a working battery in the charger (for just a moment), or putting it in a simpler trickle charger for a while (minutes? I usually forget and leave them for hours), always works.