NBN Battery Replacement for NBN™ for Sale EnerSys is the NBN battery replacement supplier for NBN™ Power Supply Units. If you chose to have a Power Supply Unit with Battery Backup included with your NBN™ installation, you will have an existing EnerSys NP7-12TFR battery. The NBN battery replacement is cost-effective. EnerSys offers NBN batteries for sale at a great price whilst providing a high quality, NBN approved product thus assuring a long service life of the replacement battery. You may hear your NBN battery beeping every 15 minutes, or your Power Supply Unit will show a red light next to the ‘REPLACE BATTERY’ symbol. This indicates that your battery has lost its charge and you will need to replace it with a new one. If this increases to 4 beeps per minute, less than 50% of the NBN battery life is remaining. With our replacement service, we offer a 12-months warranty and shipping all across Australia. That way, you can feel secure in your replacement and get the most from our low NBN battery cost.