2009 MacBook dies at 80%

Question

My 2009 MacBook has recently been dying at 80% charge, and I tried resetting the SMC, but nothing happened. I can't calibrate the battery because it won't go down to 0%, only 80%. Here's the information for the battery:
  Model Information:
  Serial Number:
  Manufacturer:          DP
  Device Name:          ASMB016
  Pack Lot Code:          2
  PCB Lot Code:          0
  Firmware Version:          110
  Hardware Revision:          500
  Cell Revision:          200
  Charge Information:
  Charge Remaining (mAh):          3568
  Fully Charged:          No
  Charging:          Yes
  Full Charge Capacity (mAh):          4356
  Health Information:
  Cycle Count:          72
  Condition:          Normal
  Battery Installed:          Yes
  Amperage (mA):          978
  Voltage (mV):          12235
It says the condition is normal, but earlier today I turned on my computer and it said service battery, but then I restarted my computer and it said normal again. Why? Does it need to be replaced? It only has 72 cycles.

Answer 1

Apple doesn’t make any batteries. They buy them from the same manufacturers that the third party sellers are buying from. The only difference is that Apple has their logo imprinted on the battery.
You can get a new third party battery fairly cheap on eBay. Every MacBook from 2006 through Mid 2009 except the Late 2008 Aluminum Unibody and the Late 2009 and 2010 White Unibodies use the same A1185 battery.
Black Batteries http://shop.ebay.com/i.html?_nkw=macbook+black+battery&_sacat=0&LH_BIN=1&_sop=12 &_dmpt=Laptop_Batteries&_odkw=macbook+white+battery&_osacat=0&_trksid=p3286.c0. m 270.l1313
White Batteries http://shop.ebay.com/i.html?_nkw=macbook+white+battery&_sacat=0&LH_BIN=1&_sop=12 &_dmpt=Laptop_Batteries&_odkw=macbook+black+battery&_osacat=0&_trksid=p3286.c0. m 270.l1313
Or for $129 from The Apple Store  http://store.apple.com/us/product/MA566LL/A?mco=MTY3ODQ5OTY