CMOS battery drain

I have an AOpen MK77 board that arrived with the CMOS battery flat. Brought a new one, and everything was fine until it died 35 days later.

So how can you test for how much power is being taken from the battery? And what is the normal level of power usage from the battery?

Could any of the hardware be responsible for the drain, or purely a fault with the board BIOS?

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  1. You would have to check the spec on the battery and then open the circuit and do a load current check with a multimeter on amps or more appropriately milliamps. If the battery is failing that often the batteries may have been weak. Checking the shelf life of the battery on the package is advisable. I would try one more battery and see what happens. If it goes bad I would then call support.
    There is nothing that can drain the battery on the motherboard unless a board run shorts in the CMOS related circuitry (thus putting a drain on the battery).
    This is, of course, highly unlikely.

    en Xristos
  2. i had the same problem with an asus p5n e sli motherboard and i solved the problem by using an old mp3 player that had a rechargable 3.3 v li-ion battery and connected it instead of the original battery using the mp3 to charge it connected to the 5v usb on the mobo when the computer is on
    so no more problem since then almost an year now :)
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