Odd Question

[thomascanty]

Can the LCD screen on a 10D get a ghost image burned into it from keeping it displayed too long?

Last week when I was in Northern California, my 10D started doing something strange. With two freshly charged batteries in the grip it would show a low battery warning as soon as I turned it on. However, I could still take hundreds of pictures on these supposedly nearly depleted batteries.

Through some experimenting, I discovered that two of my six batteries didn't make the camera do this. Those also happen to be the two batteries I use most, which means they get depleted more often. So, I thought maybe I'm charging the backups too often without discharging them completely.

The best way I can think of to discharge them is to turn the "auto off" function off and leave camera on with the LCD turned on at the menu until they just die. But now I'm wondering if this can cause a burn-in problem...

Or can someone suggest a better way to completely discharge a battery?

[tommykjensen]

Yes an image can burn into a LCD screen. But it will take a long time to do.

I would guess that You can discharge the batteries faster by just using the camera, keeping preview on, use flash and let the lens focus a lot and shoot a lot of photos.

[pradeep1]

You should be able to find one of those rapid chargers that has the ability to deplete your battery before recharging again. I think it is called a "conditioning" charger.

Maybe something like this: http://www.atbatt.com/getItem.cfm?ItemID=4751

I am not sure though if Lithium Ion batteries need to be completely discharged a recharged like NiCd or NiMH. Hmmm....Anyone else have any good ideas?

[Headcase650]

Ive read that you should NEVER fulley discharge a lithium Ion Battery.

[stoneylonesome]

The lithum batteries do not retain a memory so you do not have to complitely discharge them, same goes for the Nimh, only the old Nicad would have to be completely discharged, The batteries do wear out over time they are however usually rated for 500 or so of charges.
this link might help, even though they are discussing the RC cars

http://www.batteryuniversity.com/parttwo-34.htm

[thomascanty]

The lithum batteries do not retain a memory so you do not have to complitely discharge them, same goes for the Nimh, only the old Nicad would have to be completely discharged, The batteries do wear out over time they are however usually rated for 500 or so of charges.
this link might help, even though they are discussing the RC cars

http://www.batteryuniversity.com/parttwo-34.htm

Thanks for that link. This quote from the page confirms my suspicions.

Short discharges with subsequent recharges do not provide the periodic calibration needed to synchronize the fuel gauge with the battery's state-of-charge. A deliberate full discharge and recharge every 30 charges corrects this problem. Letting the battery run down to the cut-off point in the equipment will do this. If ignored, the fuel gauge will become increasingly less accurate.

Two of the batteries that aren't giving me a correct status are about 1.5 years old. They don't have anywhere near 500 charges on them, but they probably are nearing the end of their life. The other two are only a couple months old, though.

Thanks for the link to that charger, pradeep1. I'll look into that.

[stoneylonesome]

This is the charger that I picked up back when I got my G3, little more expensive than the one paradeep linked to, but the give you different adapters for different batteries.
Fits 7.2V -7.4V Sony, Canon, Panasonic, JVC and RCA Li-Ion camcorder batteries plus you can buy others.

http://www.thomas-distributing.com/lm-msc1.htm