Having so many digital devices means you would need lots of rechargeable batteries. Since rechargeable battery can be expensive so I would try to maintain and extend the battery life as much as possible. Sometimes it was just too bad the battery has reached the end of their lifecycle when my battery charger was blinking which indicate a dead battery.
Once a rechargeable battery is dead there was no way to revive it. Somehow some battery brands seemed to last very long while others seem to go to the grave much faster. Well, how long a battery last will depends on how often it was used, how deep the charge, how great the drain when using it on your devices.
My rechargeable batteries were mostly to be used with my digital cameras. However, I’m not always romping around taking lots of photos. Occasional travels and special occasion once in a while meant that the batteries are not being constantly used. And when it is used, the digital cameras and related photography equipment are high drain devices. So it is good to keep the batteries charged up on standby for any photographic opportunity.
I read somewhere that a normal battery loses its power about 10% per year. While a rechargeable battery after it was fully charge will lose anywhere from 15% to 25% of its charge in a year, though the newer NiMH ones could retain their charge longer than the standard NiMH types. As for the Lithium Ions, their self discharge rate is rather minimal, the only problem with them was the aging issue, even while not in use, the battery would spoil after a year or two. Though I do get a good lifespan out from them for my mobile phones which on most time last me about 2 to 3 years before needing a replacement.
Lithium Ions are more expensive than the conventional AA/AAA NiMH batteries. But in the end I found that once you started using the rechargeable battery it is best to use it frequently, because in the end the battery would lose its ability to keep its charge due to its aging issue.
I also noticed that if I were to use the battery until it was totally drained of energy, it would spoil the battery. I’m not sure if my observation is correct or whether the AA/AAA rechargeable battery has reached the end of its rechargeable cycle, but 500 times is quite a lot, I don’t think I have ever hit even the 100 charge cycle for my batteries!
So a few days ago, I started recharging some of my batteries which I have not recharged them after using them on my digital cameras after my trips and travels. It was an overly fully drained battery for my Panasonic Lumix TZ7 digital camera. This was a compatible Li-Ion battery, not the original as it was cheaper. But the charger just kept blinking indicating the battery was dead. Fortunately it was still within its one year warranty, so I could get a new set.
I also recharged my UNIROSS AA batteries which were left empty in my battery case that I forgot to charge up, and they too were dead battery as my charger just kept blinking. Same goes for my GP AAA rechargeable battery, they were drained and were left uncharged for a long period, and when I tried to charge it up, blinky lights ensued.
Oh, well, there goes the batteries, I hardly used them and they were now knocked out! So based on the above observation, I suppose even if I were not using them, I should charge them up and keep them away. However I should think for those rechargeable AA/AAA batteries, it would be better not to just store them, but to find some use for them in any devices or electrical equipment or even children toys!
For specialized Li-Ion batteries for digital cameras, you just have to use it regularly and check on it, while the AA/AAA rechargeable, use them in flashlights (which are not really high drain unless prolonged usage), or use them on children toys (some of which are rather high drain, just make sure your spouse didn’t throw them away after the power has been depleted!).
So to avoid blinking lights in the charger which means dead battery, best to use them often and charge them up regularly once you’ve bought them from the store!