i came back from a photoshoot today. I realise that my D40 battery pack(holding 2 original batteries) only managed to shoot about 300+ photos.... these batteries lasted for one week since the last charge...but 2 batteries should add up to about 2k shots....this whle week i only took about 1k.

my questions:
Could it be due to discharge?
Does frequent discharging shorten your battery lifespan?
How to maximise your battery lifespan? charge it when it is 20% and below or what?

all sifu who knows about it please share. i think everyone would wanna know too

thanks

that's really bad lifespan u got there.
are u using genuine batteries?

yup both genuine... could it be due to discharge? coz i took quite a number of shots using the built in flash...

First impression is faked battery...

I found my 30D/40D battery still full after one to two months left unused. But my 2 years old 3rd party batteries suffer discharged... but still can at least doing 1k shots over 2 month.

My guess you got faked or kong battery.

Where did you get your camera? Shashinki that kind?

li-ion/polymer :

charge it often, dun discharge it completely if possible,
if keep unused, dun let it drop lower that 40%
Keep it at a cool and dry place, hot sunlight is a killer.

But Shashinki gives very good products and I bought quite a number of stuff from them and they are still working very well. Unfortunately those things that I bought not from Shashinki gave me problems instead (my D200 in the shop getting new PCBs hehehe)

But in regards to being able to shoot 300+ photos with a battery pack is a little short. Are you sure that the batteries were fully charged?

erm..i took about 1k shots the whole week...and took 300+ TODAY alone is that normal?which means my whole 2 batteries charge i took bout 1k+ shots

anyways...this is my batteries... looks 100% ori to me

Made in China.. ya, both are genuine

hm...so just dont lets your battery become empty thats it? always keep it above 40%?

For battery care, do not over charge, do not over discharge. If you think that you would be using your camera for more than 2 weeks, just take the battery out from your camera. Even if you're storing your battery, it's better to leave at least 50% charge into your battery before storing.

Although some claimed that Li-Poly and Li-ion doesn't have any memory effect, but it's always better to practice the above mentioned ways of battery care so they'll last longer.

Yep, that's what they say here: http://www.batteryuniversity.com/

No matter it's a laptop, PDA or camera battery... As long as it's not NiMH (Li-Ion/Li-Poly), the "don't drain it" rule applies... But then again, batteries - like everything else (especially Tamron lenses... ) - have sample variations, some batteries (even of the same kind) die faster just because they were made that way...

AND, they say overcharging is fine, although the HEAT generated by doing this = kills batteries...

thanks dude..

using your flash alot reduces the no of shots that can be taken as well.

If you were using on-camera flash, you answered your own question. Battery life will drop drastically on the D40 if flash is used.

Other than that, the general rule of batteries:
- don't drain it till 0% (I top up once I reach home) to increase its lifespan
- performance will be bad if it is too cold/hot (but this is temp)
- after a few hundred/thousand cycles of charge/discharge, battery will need replacing (they do have a lifespan you know?)

I kindly worry of this too. It's better you get your self 2 batts. Charge only when no power. This is what i did.