Hi,
In general the ASA does not have any limit to the number of ACL's limit. You can configure as many ACL's based on the available memory on the device. Whenever you apply an object-group, the ASA would internally expand those ACL's into multiple ACE's, so the expanded ACL is the original count. It depends on the platform and the memory installed. On some higher platforms like it might go higher than 2 million.
If you want to check the number of ACE's in your config, try:
show access-list | in elements
Hope this helps.
Thanks,
Varun
Thanks,
Varun Rao