Canon 40D Battery Care

Trapshooter

I have heard that you should allow rechargeable batteries to completely drain prior to recharging so they do not develop a memory (shorter charge). I currently have two batteries that I am using in my Canon 40D battery grip. Unfortunately, I am not exhausting that batteries during a single soccer game (on one day) and I do not think they will last long enough for the next game (different day). I do not want to ruin my batteries and have not had the chance to buy more batteries.

So, how many of you let your camera battery completely drain prior to recharging? If you do allow the batteries to drain, how do you drain the battery prior to recharging other than leaving the camera on?

Thanks for the help.

Richard

While full discharge was recommended for NiCad batteries, I don't believe it applies to the 40D's lithium-ion. Leaving the camera on will not drain the batteries as long as you have it configured to sleep after a set time. Personally, I just use batteries till they run dry, but out of laziness, not concern about "memory" factors. I don't think you need to be concerned about recharging before each event, if you're shooting thousands of frames.

SimpsonBrothers

I have 6 batteries that I rotate through. Use until they die then recharge as needed.

hgernhardtjr

Lithium-Ion cells are totally unlike NiCd cells. Forget what you learned about NiCd when it comes to lithium cells (li-ion, li-po, etc.).

Li-ion should never be discharged too low and most equipment prevents that by simply shutting down.

Moreover, li-ion batteries cannot absorb overcharge, so be sure to use the correct charger (i.e. the battery charger that comes with the camera) for your battery which prevents even a trickle charge. Improperly designed (or the wrong) chargers that do not shut down once full charge is reached can cause lithium batteries to swell and even burst into flame.

I trust my Canon (and Sony) camera battery chargers as being well designed, and generally charge my Canon/Sony li-ion batteries just before a shoot, no matter the state of charge.

Bottom line: li-ion batteries never take a memory and really can be safely charged anytime in the "middle" as long as you use Canon's (or any manufacturer's) battery-specific chargers.

NeilL

hgernhardtjr wrote: »

Lithium-Ion cells are totally unlike NiCd cells. Forget what you learned about NiCd when it comes to lithium cells (li-ion, li-po, etc.).

Li-ion should never be discharged too low and most equipment prevents that by simply shutting down.

Moreover, li-ion batteries cannot absorb overcharge, so be sure to use the correct charger (i.e. the battery charger that comes with the camera) for your battery which prevents even a trickle charge. Improperly designed (or the wrong) chargers that do not shut down once full charge is reached can cause lithium batteries to swell and even burst into flame.

I trust my Canon (and Sony) camera battery chargers as being well designed, and generally charge my Canon/Sony li-ion batteries just before a shoot, no matter the state of charge.

Bottom line: li-ion batteries never take a memory and really can be safely charged anytime in the "middle" as long as you use Canon's (or any manufacturer's) battery-specific chargers.

Excellent reply, thanks!

And excellent question, Trapshooter! I also have the 40D with grip, and 3 batteries. That same question has been on my mind. I usually recharge after a big shoot and before another big shoot. The battery charger is often blinking one or two when I start recharging. I have never run my batteries down to where the camera switches off. My batteries have been performing brilliantly. I have never needed the spare, and it holds its charge for months on end.

Neil