As I said in post #12, I'm aware of issues regarding lithium batteries.

I can find no blanket prohibition on batteries in general.

As for Australia Post here is what they say about lithium batteries.

QUOTE:
You'll find lithium batteries or cells in portable electronics. They're a dangerous good and present a fire and safety risk if transported incorrectly. Australia Post limits how lithium batteries can be sent, and you're required to send these items in compliance with Australian and international regulations.

What types of lithium batteries can be sent?

Regardless of what domestic or international mail service you use, Australia Post can only carry the following types of lithium batteries:

* Lithium ion (rechargeable) - 20 watt-hour per cell or 100 watt-hour per battery
* Lithium metal (non-rechargeable) - one gram per cell or two grams per battery

Lithium batteries can only be sent internationally (air or sea), or domestically by air if the battery or cell (maximum of two batteries or four individual cells) are installed in the device and meet all the packaging requirements.

Recalled, damaged or non-conforming cells or batteries are also prohibited from being sent by Australia Post.

How to package lithium batteries

Make sure that the electronic device you're sending can't be turned on accidentally, and you have used strong internal and external packaging. Under no circumstances should lithium batteries be packed by themselves, or alongside a device. To find out more on how to package your batteries correctly refer to the Dangerous and Prohibited Goods and Packaging Guide (776kb).

Sending lithium batteries overseas

Shipments of electronic items containing lithium cells and batteries are prohibited when sent using the International Courier product.

You cannot send lithium batteries to Germany, Italy, Laos or Macao. If you do, your item will be refused or returned to sender.

Check our International Post Guide for any local restrictions in place before sending Lithium batteries overseas.

Lithium batteries can catch fire (example: samsung smartphones). They have also caused aeroplane crashes.

http://www.flyingmag.com/news/ups-747-crash-highlights-lithium-battery-danger

Obviously batteries get into Australia somehow, so there must be safe ways to transport them.

I see no issue using a bunch of 9 volt batteries other than it's not original. They, at least, will not be catching fire or leaking all over the place.