1) Make sure that the battery3.dll, battery4.dll, etc. is located in VST folder scan path.
Mine work fine.
2) Test using a simple plug-in host like savihost or FL Studio's MiniHost and verify that the plugin works i.e. isn't corrupted.
Native Access just checks to see if the plugin is installed not that it's working.
3) if 1 & 2 are OK - rename the DLL extension to WasDLL or something else. And then rescan your VSTS.
If Battery formerly failed a scan it may be marked as a bad plugin - if the scan can't find it, it will get deleted from the plugin database.
Then rename extension back to DLL and rescan your VSTs again.
Good luck.