When homes have an alarm system installed it usually contains a backup battery in case of power failure. These batteries need to be replaced every few years to ensure the system performs correctly.
The waste batteries are usually sold to scrap dealers for their lead content, but alarm installers are usually happy to give/sell them to you for an incredibly low price. We have picked up 7AH batteries for less than 50p each.
In this instructable I aim to show you how easy and cost effective it can be to "recycle" these for your own projects, such as a UPS/CCTV system.
The project was designed, tested and built by myself and Dom. We are fairly experienced with electronics and suggest that this project should only be undertaken if you have done all the appropriate research beforehand (also see safety disclaimer on step 2).
Step 1: Part 1 - Gather parts
8x 7AH Sealed Lead Acid batteries - £4 - Alarm installation company
700w modified sine wave inverter - £25 - Gumtree (classifed ads site)
Selection of wire, mostly mains flex - £0 - Had this laying about at home
2x 8 way earth block - £3.92 - Toolstation
3 pole double throw 240v relay - £4 - Ebay
2x 13A plugs - £0 - Had these laying about at home
Double gang socket - £0 - Had this laying about at home
Extras for CCTV:
Old computer (Prusabox) - £0 - Came from a family member, saved from the tip!
RCA cable - £2 - Ebay
EasyCap - £4 - Ebay
IR Night Vision CCTV Camera - £9 - Ebay
LAN Cable - £0 - Had this laying about at home
Optional: Instructables T-Shirt for optimum DIY-ness