[adifrank]

With laptops I've been told that it is a good idea to completely drain the battery and then charge it up to full again every month or two. As I've understood, if you don't do this the battery's capacity slowly diminishes.



With a miniDV video camera I once had I got similar advice and in fact the battery charger had a feature where I could select to either (a) just charge the battery OR (<img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/cool.gif' class='bbc_emoticon' alt='B)' /> discharge and then automatically recharge the battery.



I was curious if there are tips such as these, that I should know about regarding the battery used with the Canon 5D mark ii.



The only instructions I've come across so far (in the camera manual) say to remove battery from camera when camera is not in use; and that its best to charge battery before use, regardless if you haven't used it since charging it last. Apparently the battery drains a a bit when not in use and even more so when in the camera.



Is there more advice I should keep in mind - battery-wise? THX <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/cool.gif' class='bbc_emoticon' alt='B)' />

[Rainer]

[quote name='adifrank' date='20 July 2010 - 09:29 PM' timestamp='1279654153' post='1173']

With laptops I've been told that it is a good idea to completely drain the battery and then charge it up to full

again every month or two. As I've understood, if you don't do this the battery's capacity slowly diminishes.

[/quote]



This advise comes (very likely) from times when NiCd batteries were used

much more. It completely applies to them and to my knowledge even metalhydrate

batteries do last longer with this practice (albeit they do not have the memory-effect

like NiCds) Lithium-Ion batteries can be recharged often, even if they are not drained

out (in fact they live longer if you recharge earlier) ... important thing is, not to overcharge

them (but this applies to all sorts of batteries). On the other side, 3rd party batteries

are quite affordable, and I wouldn't use original batteries in my camera, so I usually

use a battery until the camera says it's empty, then recharge it.

[scottburgess]

[quote name='adifrank' date='20 July 2010 - 12:29 PM' timestamp='1279654153' post='1173']

With laptops I've been told that it is a good idea to completely drain the battery and then charge it up to full again every month or two. As I've understood, if you don't do this the battery's capacity slowly diminishes.

[/quote]



I'm not well versed in battery technologies, and we don't yet own the 5DII, but from what I have read most of the memory effects are from impurities in the batteries. And today the "highest-quality" LiIon suffer very little from this apparently. With our Canon batteries (different models from yours), we've really not seen this effect in several years of use, even when changing the batteries before they're dead. Our LiIons will hold a charge for months without use. But when our batteries finally drain they do so very quickly, so the warning indicators on our cameras are close to silly.



[Note: NiMH batteries are a totally different beast designed to give high bursts of power but suffering from rapid draw-down. NiMH are great for flash units, but can't hold a charge over time and also lose a charge quickly if cooled. You wouldn't want that behavior in a camera body battery. Sanyo's development of Eneloop batteries was a response to their shortcomings and intended as a replacement for NiMH technology.]



We carry spares with us always (and chargers!). We have an accessory plug/extension cord setup that allows us to recharge them in the car via the cigarette lighter, which is handy for longer trips. But as I recall, when we shopped to buy the spares, many folks on Amazon and elsewhere were warning about memory effects in the off-brand replacements. Consequently, we bought only Canon batteries. We're happy with them.



My experience with an Canon accessory grip that takes two of the Canon LiIon batteries is that I get about 60-70% more shooting time than with a single battery, but that's a very rough guestimate. How much you dither at the controls will affect things considerably. I'm more of a ditherer than my wife is partly because I do a lot of macro work.



Lastly, I don't know how critical it is to remove the battery when the camera is not in use. I would find that annoying when I am hurrying to grab a shot of some cool bug. ;-) The only Canon item we have that drains its batteries if they are left in is the Macro Ring Flash MR-14EX, and that vampire will suck AA's dry overnight! We wonder if the flash has a manufacturer's flaw, so note that your camera could vary from the experiences of others.



Hope this helps...



Scott

[popo]

Sanyo Eneloops are still NiMH fundamentally. They're just optimised for low self discharge.



Personally I have only bought off-brand batteries for compacts, and they have performed as well as the original in that case. But that is usually more due to the original manufacturer battery costing a ridiculous proportion of the whole camera cost, up to half! With DSLRs the battery cost in comparison to the body is much less significant.



As for removing from the camera when not in use, I can only assume that is a safety precaution for the paranoid. I never take LiIon batteries out until they need charging, and for normal use I can't say I really notice any significant discharge when not in use.



I do echo the comment about the flash though. I have the Sigma ringflash, and that seems to suck batteries dry even when off. So I do take batteries out of flash units if I'm not using them for any long period.

[wim]

Removing the main battery from a camera is not a good idea at all. I t means that the backup battery, which also keeps the internal clock going, gets drained much faster, and that is both harder to change as harder to obtain, and is not rechargeable.



With PDAs/cell phones this battery gets drained well within three days, generally speaking, when the things is not in use, so I would not risk this from happening.



I have similar experiences with ring/macro flashes, with regards to the battery drainage, including those with in-built Li-Ion batteries, with the exception of my old Cokin Creative Flash set. That is the only one that doesn't do that, and is by far the cheapest I ever got (50 euros used <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='B)' />). The hot shoe flashes (430, 580) don't drain batteries, fortunately, when switched off <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='B)' />.



Kind regards, Wim