Can be changed in settings.xml.
<General>
<AutoRecoveryExtension>.auto.tmp</AutoRecoveryExtension>
<AutoRecoveryDelay>30</AutoRecoveryDelay>
</General>
AutoRecoveryExtension - default extension for Auto Recovery files
AutoRecoveryDelay - controls how often, recovery information should be changed. Here 30 == 30 seconds.
#xml_option