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I just want to make sure before I destroy my arduino.. Is it okay if I power my Arduino Mega from a high current 7.2v battery pack? The battery I'm planning to use is this :

http://www.ebay.com/itm/7-4-V-30C-5200mAH-2S-Lipo-Li-Po-Lipoly-Battery-for-RC-Car-Boat-/261351067166?pt=Radio_Control_Parts_Accessories&hash=item3cd9bcce1e

The voltage is within the recommended 7-9V and it's a 5.2A pack, and the arduino will only draw as much current as it needs, so I don't need to worry about current, do I?

Note: I will be connecting GPS/GSM module, and some other sensors. I won't use any motors for cars or boats. I need this because I want the arduino to live as long as possible!

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It should be OK but be aware that the voltage regulator device on the arduino may not regulate when the battery voltage drops below 7V because, from memory it is a 7805 device and it, for proper operation needs a minimum of 7V to ensure the output remains regulated.

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    \$\begingroup\$ You are right about 7805 but I guess it depends on the specific implementation, not all board use it. For example I checked a couple of Arduino UNO and they were using MC33269 and LM1117, both low dropout regulators that only require about 1.2v higher input. In any case the OP should check the requirements of the regulator used in his specific board. \$\endgroup\$ – alexan_e Jan 6 '14 at 12:12
  • \$\begingroup\$ Thanks Andy and @alexan_e Any suggestions to solve the voltage drop issue? Other than using a higher voltage battery. \$\endgroup\$ – Adel Bibi Jan 6 '14 at 13:16
  • \$\begingroup\$ @AdelBibi you could use a boost voltage converter to guarantee (say) 7V5 output even if the battery dropped to maybe 6V. The alternative is to swap out the 7805 on the arduino board with a low-drop-out regulator. \$\endgroup\$ – Andy aka Jan 6 '14 at 13:26
  • \$\begingroup\$ @AdelBibi A boost converter that will be converted back to 5v will lower the efficiency, I think a low dropout regulator like LM2940-5 with a typical voltage drop of 0.5v at 1A (1v max) and much lower at lower currents (typical 0.11v at 100mA) would suite your application. \$\endgroup\$ – alexan_e Jan 6 '14 at 14:35

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