Is it safe to store an LP-E6 battery attached to the charger? Or does that discharge the battery quicker than storing it separately?

Normally I will store an extra LP-E6 on the charger in my camera bag, just as you describe.

However, I make it a point to "top off the charge" on all batts. before using the camera. So I'm not able to say anything about any slow discharge, sorry.

Another thing I do because I'm so forgetful sometimes: when I remove a batt. from the camera, I leave the camera battery access door *open* to remind me there's no battery in it.

If there's a heavy lens or other gear on the camera, sometimes it's hard for me to tell if it has a battery in it just by feeling the weight. So I leave that door open as a visual reminder to put a battery in it.

Hope this helps,

Thanks. What do you mean by "top off the charge"?

By that I mean: plug the charger into a wall outlet and charge the batteries -- which are usually fully charged after the last time I used them. But, like you, I wonder if a batt. discharges if it's mounted on a charger while stored in the bag. Therefore, I'll do a quick charge before going out for the day, to "top off the batteries," so to speak, so that I know they are completely full. Since they are already mostly fully charged anyway, it never takes very long... usually just a matter of a few minutes. Hope this helps,

I see... thanks

Having just bought some LP-E6N batteries, I charged them and then did a test. I checked the charge of two batteries by putting them in the 6D, which reported 98% charge on both of them.
I put one in the charger and set the other aside as a "control".

I periodically put them back into the camera to check the status. That action will use a little bit of power, so after checking them both about 6 times over the past 56 hours, they are now at 96%. I'll keep it going for a few more days, but so far it looks like the battery won't drain any faster on the charger.

Mark

That's most helpful to know. Many thanks, Mark!

Based on an experience where the battery pack for a cordless drill was ruined (went into a melt-down mode and warped the plastic case) by inadvertently leaving it on the charger, this isn't something I'd do. The problem with the battery actually ruined the charger, too.

Granted, most camera battery packs are smaller mAh-wise, but I'm careful to keep track of my battery charging now and when the indicator shows it has been topped-off (reached full charge) the battery is removed and the charger is turned off.

Your (battery charging) mileage may vary.

After a full week in the charger, the battery is at 94%, same as the battery that was stored out of the charger. I think it's safe to say the battery charger doesn't drain the battery.

Mark

Thanks, Mark and thanks guys.

In general, leaving a Li-Ion battery on the charger after it has reached full charge serves no useful purpose, and if the charger is plugged in wastes energy. It might actually shorten battery life a bit. And depending on the charger design might actually put some drain on the battery when not powered. Similarly long term over charging has been credited with causing some of the NiCad "memory" effect.

The usual advise for long term storage (e.g., for the winter) is to store Li-Ion discharged and then charge before use. Li-Ion technology does not self discharge quickly the way NiCad and NiMH do, so a week later you should still have a nearly full charge if stored off the charger and not in the gear.

On the other hand traditional lead-acid batteries like to be kept on a charger in "float" state.