FrozenBlue

Both the EOS-1D Mark III and the full-frame EOS-1Ds Mark III use an entirely new lightweight, powerful lithium-ion rechargeable battery system. The LCD monitor provides an accurate reading of power percentage remaining, shots taken since last charge, and whether the battery should be reconditioned. This takes much of the guesswork out of battery management.                                
Not only is the new battery significantly smaller and lighter than the Ni-MH battery previously used in the EOS-1D series bodies, but it actually powers the camera for more shots on a single charge. One of the most interesting aspects though is the new battery management system.  Users can now see precise read-outs right on the camera’s menu screen for a variety of functions. 
We explore the details in this document.                            

The new LP-E4 Lithium-Ion battery pack: The new LP-E4 battery pack is exclusively for Canon’s EOS-1D Mark III and EOS-1Ds Mark III, and cannot be used in earlier EOS models. When installed, the either camera is about ½ lb. (approx. 220g) lighter than its predecessor.

Memory Chip                            

A memory chip in the battery pack provides comprehensive information to the user via the camera’s menu. It’s also the reason why the camera has a six-stage battery check icon in the viewfinder and on the top LCD panel, which are constantly visible.

CIPA Industry Test Standards                            

At 73°F (20°C), a fully-charged battery can power the camera for up to 2,200 images (about 1,800 with the full-frame EOS-1Ds Mark III). Even at the freezing point (32°F, 0°C), the LP-E4 battery is good for up to 1,700 images with the EOS-1D Mark III (about 1,400 with the EOS-1Ds Mark III).

Charging the battery:                            

Both Mark III cameras ship with a dedicated LC-E4 battery charger, which is for exclusive use with the new LP-E4 battery packs.  One or two batteries can be attached and charged;  if two packs are connected, the charger fully charges one battery first, and then the next.  Full charging takes about two hours per battery pack.
Unlike the previous-generation battery charger, LEDs clearly indicate the LP-E4 battery’s state of charge, with clear indicators printed on the charger to alert the user when a battery is fully charged.  The battery charger can also be used to Calibrate LP-E4 battery packs – more on that in a moment.  Like virtually all Canon chargers, the LP-E4 is a multi-voltage charger than can travel almost anywhere, needing only a plug adapter.  AC voltage from 100v to 240v are automatically sensed, and no voltage converter is needed.

Battery Info on the camera’s menu:                            

This is really new. Both Mark III models are the first Canon cameras to be able to comprehensively communicate between battery and camera, and report precise information to the user. For users who want to quickly be able to check the status of their LP-E4 battery, one suggestion is to add Battery Info to the six available choices from within the “My Menu” setting which allows a user to set and access their favorite or most commonly-used settings quickly and easily.

Now, once a user selects Battery Info, the following screen will appear (Please note: The battery calibration display only appears at select intervals (usually after 20 or so battery charges):

Here’s what the Battery Info tells the photographer, from top to bottom:

Power Source:  Reports whether the Canon LP-E4 battery pack is in use, or the (included) AC Adapter Kit ACK-E4 is being used.  If a third-party battery is being used instead of a Canon-brand battery, this can be reported as well.
Remaining Capacity:  Shows both the six-step icon, but also reports remaining percentage of battery charge in 1% increments.  This provides an extremely precise read-out to help the photographer stay on top of battery usage.
Shutter count:  Reports the number of exposures taken since this battery was last charged.  No, this does not report the total number of shutter actuations by the entire camera!
Recharge Performance:  Reports in three steps how well the battery retains its power.  Three green squares mean a full-functioning battery.  When it’s down to only one red square, the camera is telling you that the battery is past its useful life, is no longer holding a charge effectively, and should be discarded and replaced with a new one.  Simply recharging, or calibrating, won’t help the battery regain full performance potential at this point.
Calibration recommended:  After charging the LP-E4 battery about 20 times, you’ll see an additional line of text at the bottom of the Battery Info display suggesting it’s time to calibrate the battery.  This intentional discharging and subsequent re-charging of the battery pack is done in the standard LC-E4 battery charger. 

Calibrating the battery:                            

Please note: the Lithium-Ion battery has extremely good “memory” characteristics and periodic discharging and re-charging of the battery – sometimes called “refreshing” – is not needed to keep the battery’s power level strong.  Users can freely charge the battery at any time, regardless of whether it’s nearly depleted or has only been briefly used since its last charging.  There is no problem with topping-off the battery by charging it, even if it’s close to fully charged beforehand.
The Calibration procedure here is strictly to keep the Battery Info calibrated, so that the display remains accurate.  Here’s why:  as the battery is repeatedly used, charged up, and used again, there can be a gradual change in the information being provided to the camera vs. what’s actually going on in the battery.  The menu’s display of percentage of charge, in particular, can sometimes drift from accurate readings.  The Calibration procedure basically brings the Battery Info back in-line with what the camera is reporting.
The important thing here is that users do NOT need to fully discharge the LP-E4 batteries for the cameras before charging them up, even if there’s an important shoot the next morning.  Simply charge the batteries, until the camera recommends the Calibration procedure in the Battery Info display.  Calibration (which can also be recommended by a blinking red “Cal/Charge” LED on the charger, when a battery is inserted) takes about 10 hours to fully discharge each fresh battery pack, followed by the normal two hours to charge each back up.  For maximum battery life, we recommend users wait to perform Calibration until the camera or charger recommend it, and that users avoid the old habit of refreshing batteries prior to charging “just to be safe.”

Summary:                            

The new battery system in the EOS-1D and 1Ds Mark III cameras is an outstanding leap forward in virtually every aspect.  It’s a lot lighter, it performs even better, and it’s got a comprehensive method of reporting battery status back to the photographer.  An understanding of what each Battery Info item is explaining, along with the details of the Calibration procedure,  goes a long way toward getting the most out of this new system.

The CDLC contributors are compensated spokespersons and actual users of the Canon products that they promote.

reference : http://learn.usa.canon.com