Flash Battery Power

[samsim]

I have a Canon speedlite 580ExII and I use Sony's CycleEnergy rechargeable (typ.2500mah) batterys , which take roughly 14hours to fully charge . My question is if i charge it for 14hrs fully charged and I dont use it for over a week and then use it does the charge remain at 100 percent during the period of non use or i would have to put them in for charging all over again just before I use them. Thanks in advance

Samsim

 

[Overread]

From what I can tell the CycleEnergy batteries made by Sony are the kind that will retain their charge even when left inside a unit. So after a week the amount of energy loss would be negligible; even after a year they would still hold a good portion of the charge. So you should be free to use them as and when you need them without having to recharge just before use unless you've already drained them out fully previously

 

[tirediron]

I'm not familiar with those particular batteries, but most rechargable dry cells do lose power just sitting on the shelf. That said, I wouldn't expect the loss over a week to be significant. Do a test; charge a set fully, and then see how many times you can trip your flash before the recycle time becomes egregious, and then recharge them, let them sit a week, and see how many times you can trip them before the recycle time gets to the same point as before.

 

[Braineack]

...let them sit a week, and see how many times you can trip them before the recycle time gets to the same point as before.

or measure the voltage before and after a week of storage; less counting.

 

[KmH]

Sony's Cycle Energy rechargeable

http://www.adorama.com/BYSOCE2AA4.html
Pre-charged and ready to use right out of the package, these economical, environmentally-friendly Nickel-Metal Hydride (NiMH) batteries can be recharged up to 1,000 times. Additionally, each battery maintains 75% of the charge after one year and features an automatic charge cut-off timer.

 

[Derrel]

I have heard 3% to 1.5% per day as normal power loss in "regular" rechargeable modern batteries. But the Sanyo Eneloops and the Sony Cycle Energy batteries do not have that power loss problem; 75% power after a YEAR sitting idle means that at a week later date, the batteries are basically just a tiny decimal fraction less than 100%, so for all intents, they are FULLY charged.

 

[samsim]

Thank you all for the responses and suggestion.....
I shall manually test it as well as suggested to be 100% sure . Thanks once again

 

[TCampbell]

I have heard 3% to 1.5% per day as normal power loss in "regular" rechargeable modern batteries. But the Sanyo Eneloops and the Sony Cycle Energy batteries do not have that power loss problem; 75% power after a YEAR sitting idle means that at a week later date, the batteries are basically just a tiny decimal fraction less than 100%, so for all intents, they are FULLY charged.

Panasonic acquired Sanyo -- consequently you can now find "Panasonic Eneloop" batteries on the market. I had thought that implied there would be no more Sanyo Eneloops... but a check of the website leaves me with the impression that they may be selling the batteries under both brands.

 

[Overread]

Aye that either means they are still running older stock through the system or that they are simply keeping both names and running different markets with the brand identities.