Give me some tips about rechargeable pencil battery.?

Question

I keem them in the battery chamber untill they get fully discharged.

Answer 1

Normal alkaline batteries just don't do it for digital cameras because of the high instantaneous current required to run a digital camera. (This includes all batteries such as "Duracell" and "Super Heavy Duty" etc) These types of batteries will appear to the camera to be flat even when they aren't because they just don't have the capacity to give the camera what it wants.

Some places still sell rechargeable Nickel Cadmium Batteries (NiCd), and these batteries cannot cut it for digital cameras. There are also rechargeable alkaline batteries and these aren't great either.

The only type of rechargeable to get is Nickel Metal Hydride (NiMH), and the higher capacity the better. This capacity is typically rated in milliamp hours. A medium capacity battery for a camera will have say 1600 MAH whereas a high capacity battery will have more than 2000 MAH. Some even go as high as 2600 MAH. Get the highest that you can.

One downside is that NiMH batteries go flat in the camera if you do not use them. In a camera that uses 2 batteries, this can happen in as little as a week.

My advice is get a couple of sets of high capacity NiMH rechargeable batteries (2000 MAH or higher) and use these as much as possible. Also however buy one or two sets of Lithium batteries (non rechargeable) these last a long time but are wickedly expensive. Have one set of lithiums for backup in case you need the shot but the rechargeables are all flat. Soon as you can put freshly recharged batteries in and again keep the lithiums in reserve. Unused lithium batteries will last for years.

Many cameras have a menu setting which can flatten the batteries for you prior to recharging. ONLY IF you are using NiMH batteries is this a good idea. Vendors tell you that NiMH are not prone to "memory effect" and therefore do not need to be totally flat before being recharged, but this is not true. NiMH bateries should be discharged before being recharged. If the camera can't automatically discharge them, then keep using the camera until it won't go anymore, then recharge them.

Hope this helps.

Answer 2

Just to add on to what has been said earlier by teef_au (good explanation)...

There are now rechargeable NiMH batteries in the market that have a very low self discharge rate. In other words, these batteries do not die in a month or so if not in use. Instead these can be on the shelf for more than a six months (or more) and lose only about 10% of their charge.
I do own some of these batteries and they are great for appliances that are not used regularly (clocks, flashlight, calculator etc). These batteries come in a lesser mAh rating than regular NiMH batteries. Regular NiMH go upto 2700mAh where as these max out at 2100 mAh.
Examples of these batteries are:

Sanyo Eneloop ( http://www.eneloop.info/ ) - $12.00 for 4 AA
Rayovac Hybrid ( http://www.rayovac.com/recharge/index.shtml ) - $8.99 for 4AA at Walmart stores
Unicross Hybrio ( http://www.batterylogic.co.uk/hybrio.htm ) - $9.99 for 4AA at Fry's Electronics