My Google-fu is failing me. I just bought a 4.5Ah Bioenno pack to run the KX3, but I'd like some way of determining state of charge so I know when to shut off before damaging the battery. I know that voltage measurement alone doesn't help much with these, as the discharge curve is very flat, but maybe something that plugs into the charge port? Or one of those in-line LCD wattmeters that would count total discharge?

Much thanks...