USB Charger

[MicciMan]

I've found that the Nebula USB charger signals that the battery is fully charged when it's not. If I take a charged battery off the USB charger after the charger light has gone blue (3ish hrs for a drained battery), and then put the battery on my AC charger, it immediately begins charging.

So far I've tried this w/ 2 batteries. Each one will sit on the AC charger for about an hour before they are truly fully charged.

I don't suspect this is defective gear, but perhaps something with the circuitry in the USB charger measures charge differently?

 

[PhiHalcyon]

The over-charge cut-off voltage on the USB charger must be slightly less than on the AC charger. But, since the last hour of charging accomplishes far less than the first, and it only takes an hour on your AC charger to reach the maximum over-charge voltage, I suspect that the voltage differences between your USB and AC charged batteries is probably rather small. For example, rather than over-charging your 3.7 volt battery to the maximum 4.2 volts, your USB charger may be over-charging to something like only 4.0 volts.

Since I rarely take my batteries to the point that they flash for a recharge, I would probably never notice the difference; but if you tend to use your batteries as long as you can before changing them, then the only difference will be that your AC charged batteries will last for more puffs than your USB charged batteries.