Batteries - Charge them every time or let them run down then charge?

So I have been having this dilemma:

1. Charge your batteries each time before you go out on a shoot to full capacity even if they have only been run down for an hour or so. ( LP-E6 Camera and AA batteries ) So they are 100% fresh each time.

-or-

2. Let the batteries sit and just keep them using them for each gig until it runs down, then pop in a charged battery and then recharge the other one that is dead back to full capacity?

This might seem like a silly question but I am wondering about Battery life vs. always having 100% charge each time I go out to shoot. Now I have always thought its cheaper just to go buy a new battery if I wear down the life charging it everytime before a shoot even if its at 90% rather than just let it die down naturally 3 or so shoots I might have in a row. Any thoughts on this subject?

thanks!
JTP

I always top off my batteries the night before. Why leave the house with an unknown and possibly weak battery to start the day? At home, when the camera is not being used too much but is ready for any unexpected shots of my kid, I just let the batteries run until the camera tells me they're low.

The only times I tend to fully recharge them is if I expect to be using them a lot.
Posts #9 & 10 in this 2005 thread might be helpful general info: https://photography-on-the.net …/showthread.php​?t=117548&

I always let the battery run down to under 20% before charging. If I have my camera bag with me, then I have a spare battery that's fully charged in it. If not, then I make sure I have enough power to last through what I'm doing. My batteries last quite a while though, and this works well for me.

Always let them run down, they'll have a longer lifetime.

Keep spares in your pocket, they're small. It takes 20 seconds to change a battery.

Let them run down.

Yep let them run right down and fully charge them, makes them last a little longer.

Depends on the camera and type of battery. The Canon 5D mark II uses the lithium-ion LP-E6 battery.
The battery does not have the memory effect. Because of this I prefer keeping them charged.

Do some reading on Lithium-Ion (LP-E6) batteries: http://batteryuniversi​ty.com …ing_lithium_ion​_batteries

Lithium ion batteries should NOT be run all the way down. You run the risk of plating-related shorts which can result in a fire when the battery is put back on charge if the internal protection circuit fails to detect it.

There is no particular problem with recharging a Li battery at any time, but they should not ever be "floated" with charge current running. Commercial chargers are designed not to do that ever as it is also a safety problem in that metallic lithium will plate out if it does happen, and if the cell then is physically damaged (e.g. it gasses and bursts) you get a fire that is almost impossible to extinguish.

The biggest risk with "fully" charging a LiIon battery is that the charger is poorly designed and overcharges the pack. This is quite dangerous but fortunately most chargers are smart enough to avoid doing it. Lithium cells are very efficient in both accepting charges and discharging and thus do not normally (under non-abusive loads or charge rates -- RC folks can ignore this as they abuse these packs all the time and occasionally pay for it!) get materially warm. A lithium battery should NOT get more than slightly warm while charging; if it does it's defective or damaged or the charger is malfunctioning. Figure out which and discard the offending device before you have a catastrophe.

I run mine down to about 30% before recharging most of the time. If there is a important shoot coming up then I will charge the batteries no matter what their level is showing. Guess the poll should have a the option for "C" all of the above.

Calicajun wrote in post #15564477
I run mine down to about 30% before recharging most of the time. If there is a important shoot coming up then I will charge the batteries no matter what their level is showing. Guess the poll should have a the option for "C" all of the above.

This.

Lithium batteries last a lot longer if you drain, then charge instead of just "topping off". I come from a background of high end R/C cars. (I'm talking about $2k+, 60mph, 4HP) I used lithium batteries in mine. The batteries were very expensive and they lasted the longest when properly cycled.


Now if you have something important coming up, then I'd top off anyways.

NEVER discharge a multi-cell battery all the way. The reason is that all of the cells are never identical and when the battery gets nearly fully discharged once cell will be totally flat before the rest. That cell will then be reverse-charged by the rest when you continue to discharge the battery. This will ruin an otherwise good battery.

A very bad thing to do to a Li-ion battery is to run it out completely all the time. Full discharges put a lot of strain on the battery. It is better to do shallow discharges to no lower than 20 percent. Li-ion batteries actually count charge cycles based on a 100 percent discharge even when it's summed over multiple sessions. For example, if you discharge a battery to 50 percent one day, charge it back to 100 percent, then discharge it 50 percent again the next day, that is counted as one "cycle" of the battery. So shallow discharges, in all these regards, are ideal for a Li-ion battery.