Hp Mini 311 cmos checksum is invalid ???

I have a hp mini 311 1000nr, i was upgrading the hdd so i had it open upside-down next to the window on my dresser. the window was open and i didn't know it was raining and it got soaked so i immediately removed the battery and cmos, completely disassembled it and began to blow dry it, about 12 hrs later i power it up and it gave me a "cmos checksome is invalid" error but i still got it to boot, i set the time and configed everything but as soon as i reboot the time is reset to when it was made. "aug 16 2009".

I also noticed that the bios update i had done was erased, i tried to check the battery with an led but it wouldn't light up, idk if the led was good or not and i don't have a voltage tester.

I have also tried updating the bios but when i had it shut down for a while the update was erased again. i need to fix this because the old bios is not very good and does not utilize the hdd correctly, it lags on videos when the hdd is not active.

Just a side note the stock hdd used to also do this but when i updated the bios it stopped, so i know it does not have anything to do with the new hdd.

Any help would be greatly appreciated.