#1. "RE: Battery Question" In response to Reply # 0 Fri 03-Dec-10 04:35 AM by agitater
>1. Why is charging a full Li-Ion dangerous?
It's not dangerous in the slightest. Both the Nikon battery and the Nikon charger contain logic with which they communicate to determine capacity, charge state, condition and other technical details. When the battery is fully charged, the charging circuit shuts down.
>B. What's with run it flat before charging? I thought it did >not matter with Li-Ion.
It does not matter. Nikon batteries can be charged/topped-up every day if you like, no matter how much or how little the battery has been used. Or charge only when you feel the battery won't last through the next shooting session if you like.
The only issue related to running down the battery all the way before charging, is that the last of the paltry four bars in the battery meter doesn't really provide a precise idea of the actual remaining capacity. But it has little or nothing to do with the effectiveness of charging.
A few non-scientific, uncontrolled battery charge/discharge tests have correlated regular deep discharge with a need to periodically re-condition these sorts of batteries in order to regain full charge capacity. But those amateur tests haven't been duplicated in a lab anywhere to the best of my knowledge. Since most people don't run their Nikon batteries flat all the time (because there's no reason for anyone to do so unless they're just too lazy to yank the battery and charge it before it runs out of juice in the field), it's a non-issue.
#3. "RE: Battery Question" In response to Reply # 2
>You spell it out as I have understood it to date, package >insert that comes with the battery to the contrary. Maybe I >should stop reading. What do you think? Risk adverse lawyers?
Which battery brand? Nikon? Hahnel? Energizer Accu? If it's Nikon, the answer is risk-averse lawyers no doubt. If it's a third-party brand, well, you never know for sure if they're sufficiently well designed to meet full Nikon specifications.
That said, there are rare situations in which leaving a battery (any battery) in a charger (any charger) can be dangerous. Because typical chargers contain only basic input voltage trimming, a significant AC line power surge or spike can theoretically pop the charger and any battery it contains irrespective of whether or not it's fully charged. The lesson is, as soon as a battery is charged, remove the battery from the charger and remove the charger from the AC outlet (even if it happens to be surge protected). The charger isn't a storage device. Obviously though, this potential problem has nothing to do with the battery and charger per se.