# How to drain a camera battery?



## Overread

Without clicks 
Got a trip comming up and I want to fully drain my batteries and charge them up fresh before the trip since don't want them to die on me when I get there. However I don't think I will get a chance to do any serious shooting beforehand = so I need tips on draining my 400D batteries - without shooting and without destroying them of course 

(of course doing it this way means they are probably near fully charged anyway )


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## clarinetJWD

Digital?  Leave the display on, or go into bulb speed and leave the sensor charged until it can do so no more!


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## lostprophet

Get a brick and tie it to the batteries and throw them in a river, oh wait thats drowning batteries


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## Overread

you offering to bring me fresh new batteries with you then LP 
cause once they are in the Thames there is no getting them back (might get a fish for lunch though if it gets too close to the contacts!)


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## lostprophet

400D..... that'll be those little 2L things hmmmm might have a few 2nd hand spare ones around at work I could bring


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## Overread

seriously?


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## Big Mike

I don't think these lithium batteries have a 'memory'...so you should be able to just charge them up (without draining them first) and that should be all you need to do.


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## Overread

but won't that affect their overall lifespan - one event probably won't but repeated recharging without discharge?


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## Big Mike

I'm not sure.  I think I've read that it won't...but I think they say that about other types of rechargables and I'm pretty sure that it does (with NiMH for example).  
When I recharge my AA NiMH batteries, I almost always set the charger to drain them first, then recharge.  None of my lithium battery chargers have that option, so I would assume that it's not needed.  

Either way, I use cheap off-brand batteries in my camera...so if it does shorten the life span, it's no big deal.  I'd be more worried about using the camera to drain them, shortening the life of my cameras.


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## kundalini

FYI

http://www.zimbio.com/The+DIY+Handyman/articles/8/How+Prolong+Life+Batteryhttp://www.zimbio.com/The+DIY+Handyman/articles/8/How+Prolong+Life+Battery




> 3. Charge your battery correctly, in accordance with its type. Most newer cell phones have lithium-ion batteries, while older ones generally have nickel-based batteries. Read the label on the back of the battery or in the technical specifications in the manual to determine which yours is.
> 
> *Nickel-based batteries (either NiCd or NiMH) suffer from a phenomenon known as the "memory effect." If you charge the battery partially enough times, eventually the battery "forgets" that it can charge fully. A nickel-based battery suffering from memory effect can be reconditioned, which requires the battery to be completely discharged, then completely recharged (sometimes several times). The appropriate length of time between reconditionings varies. A good rule to follow for nickel-battery cell-phones is to discharge them completely once every two to three weeks, and only when you have a charger available.
> 
> * Lithium ion batteries, on the other hand, do not suffer from the same memory effect. However, many devices that use lithium batteries have a battery meter, showing the user how much charge the battery has left. Starting with a battery's manufacture at the factory, lithium ions oxidize in the battery, shortening its life. After a certain amount of time, the battery exhibits slightly different electronic properties, which the device can only detect when the battery is discharged. This type of problem is known as a "virtual memory effect" and occurs when your battery meter can show a high charge, then suddenly drop to low charge when the battery is almost dead. Every thirty cumulative cycles, you should discharge lithium ion batteries until the phone gives a low battery warning, then recharge it. If you discharge lithium ion batteries to zero voltage, the internal safety circuit may open. In that case, a normal charger will be inadequate. Reconditioning ensures that the battery meter on a lithium ion cellphone is accurate (although it will not affect actual battery capacity).
> 
> *Regardless of the battery type, use only a charger rated for your battery, and discontinue use of a charger that causes the battery to heat up excessively.


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## Overread

interseting!
least it puts me at ease about recharging the batteries!


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## Warren_G

Some other advice, dont pack your batteries in your luggage if you are flying. My camcorder batteries were killed totally on a flight to Mexico this year due to freezing them. One of them never came back, it would not take a charge at all. Keep them at room temp for as much of their life as you can.


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## clarinetJWD

I should have mentioned that.  Li-Ion batteries do better with frequent small charges than complete drainiage/recharge cycles unlike Ni-Cd ones, so you should be good


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## kundalini

clarinetJWD said:


> ... Li-Ion batteries do better with frequent small charges than complete drainiage/recharge cycles ...


 I've read that as well, but can't find the source ATM.


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## Overread

you know now you mention it I think I have heard that before as well - though chances are my source is a forum source.


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## clarinetJWD

You can thank Corry for sending me a link the other day 

http://en.wikipedia.org/wiki/Lithium-ion_battery#Guidelines_for_prolonging_Li-ion_battery_life


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## Overread

!!
if I were not in student housing mine would be in the fridge after reading that!
I dare not risk it currently - the others might try eating or selling them


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## ferny

They used to say NiMH never had a memory...


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## Hawaii Five-O

well why can't you just leave them charged and then charge them again to give them a boost before you leave.

Dosen't make much sense to go to all that work to drain battery for no reason and then recharge it.


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## Overread

Hawaii Five-O said:


> well why can't you just leave them charged and then charge them again to give them a boost before you leave.
> 
> Dosen't make much sense to go to all that work to drain battery for no reason and then recharge it.


 
it was a question of the battery memory - essentially many rechargable batteries state that you should fully drain before recharging - recharging inbetween would lead to significant reduction in battery charge time --
of course if they don't suffer from the memory problem then there is no worry


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## pez

I would challenge what that site says about NiMH memory, as I do not believe they have a problem with charge memory. Also, NiCd batteries steadily improved on that count to the point that the NiCd packs used in R/C basically had no charge memory problem, as of a few years ago. Of course, then we went to Li-poly...


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