Recommendation for batteries

hey guys
I using a load that uses 250mAh current (that includes arduino, sensor and wireless communication) any recommendation for rechargeable batteries that supply 9 to 12V DC power and can last for 8 to 10 hr..
Basically this is outdoor project so there wont be outlet near by, therefore any suggestion for rechargeable batteries..

Do you mean 250mA? (250mAh is a measure of capacity, not current).

To last 8 hours you need (theoretically) a 2 Ah battery. NiMH batteries can usually be easily found in this voltage and energy storage range:

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The Gadget Shield: accelerometer, RGB LED, IR transmit/receive, light sensor, potentiometers, pushbuttons