20D Battery question

[gabrioladude]

this is probably one of those "no brainer" questions for the techies out there but I suspect there are a number of other non-techies, like me, who are also curious.

in the "olden days" it was important to "run down" your nickel cadmium rechargable batteries because if you didn't they acquired a "memory" and you would then not have the benefit of a full charge once you recharged the battery.

is there a similar problem with the new lithium ion batteries that the 20D uses?

in other words is it prudent to "run down" the battery totally or is is safe to recharge it when it is partially down

thx

[Eagle]

By what I've read and heard lithiums don't need to be run down, actually they like to be recharged frequently.

[WaveRider57]

That's not an issue anymore. Ni cad batteries don't have 'memory' problems.
I just charge mine when it indicates less than 50% or before I head our for a day of shooting. I'm very impressed with the 20D battery life!

[Tom Skoropad]

Lithiums do not suffer from the memory effect that other batteries do. In short it doesn't matter when you recharge.
In fact lithium batteries can be damaged by discharging to too low of a voltage. Not to worry though, most devices that use lithium batteries won't allow the battery to reach that point.
Just remember lithium batteries do of course have a lifespan. At some point later in their life you will start to see reduced capacity and no amount of discharging or chargiing will bring that back.

Cheers,
Tom

[JMHPhotography]

According to the documentation, the lithiums do not suffer the memory problem.. but if you're worried, buy an additional battery and keep it charged. When your camera indicates that it's time to recharge(and it will) pull it out, pop in the spare, and recharge the one you popped out.

[gabrioladude]

thanks for the answers
that is what I had also heard
but wanted to confirm with the experts here

[Marshall]

That's not an issue anymore. Ni cad batteries don't have 'memory' problems.
I just charge mine when it indicates less than 50% or before I head our for a day of shooting. I'm very impressed with the 20D battery life!

Where did Nicad come into the equation ? 20D batteries are Lion with no memory, Nicad
HAVE a memory so need discharching fully before re-charge, Nmah have no memory however some chargers for them recondition the batteries by dischargeing then before re-chargeing. The slower the chargeing the better it is for longevity, & chargers that top off with a trickle charge usually achieve maximum capacity, usually good for 1.000 charge re-charge cycles.

[Mitcon]

As others have said, no need to worry about your lithium Ion batteries being flat before charging. It is true that it's better for them in fact and that most equipment wont draw the battery to total loss of energy as this will damage life span. In reality even most Nicads shouldn't be drawn completely flat either as you may get cell reversal and again damage the battery.

Older batteries were best being used untill they could no longer power what they were being used in (but still having some tiny amount of power in them). They did benefit from deep cycling, new batteries such as Lithium Ion/ Lithium Polymer have no such need. Also never store a battery for extended periods of time when it's already flat as they will still self-discharge at a slow rate and may also become totally flat/depleated given enough time.

Ever wondered why when you buy a battery it has power already, I'm also not certain slower charging is better for the battery. This used to be the case because of heat generated during the charging process which is the most damaging factor to a battery (heat) but these days I thought the fast chargers were better for a battery if anything because of reduced crystalline formation. I also think the life-span of cobolt based Lithium Ion batteries was around 300-500 cycles (though capacity will go down from there you get many more before the battery is useless normally)

The reason for charging a battery when first bought or after long storage is to bring all the cells levels up to be equal as the self-discharge rate is different in every individual cell inside the battery. Lithium batteries don't get trickle charged either because they are unable to absorb overcharging so no point leaving them on after the light goes green hoping for it to top up to full, they already are.

Hope this helps everyone a little bit, and always remember to ONLY use the correct charger for Lithium batteries as it is a different charing process for these from the Nickel based batteries. And avoid excessive heat for any battery but even more so for cobolt based Lithium Ion batteries as they are able to go into thermal runaway (burn at temps upto 800 degrees c) but look after them in a normal and good fashion and they are very safe and will last you a much greater time.

[tim]

Have a read of http://www.batteryuniversity.com