.....Its not specifically an Omega Part related so it shouldn't really go in that section.
Cut a long story short, went to see an old contact of mine today (Police Bits and Bobs), anyway He's got a box of ProMax Battery Savers, these are New but not in there original packaging, they basicly connect onto the + Batt Terminal, and monitor the Battery Voltage, should the voltage fall below a preset condition they automatically disconnect and isolate the Battery from the Vehicle meaning the Battery is then left on its own for a Priority Vehicle Start.
These are a big thing in the States and are fitted to a lot of Emergency Vehicles to ensure there ready to priority start rather than a flat Battery syndrome, you get the idea.
They go for around $100 in the States, He's looking for around the £35 mark each and has 9 of them, I wouldn't mind 2 or 3 for myself, handy if you've got a second car parked up thats not being used on a regular basis, I reckon if I put an offer in for the lot I can probably get them for 20 to 25 each, so if anyone is interested in one and I can make up the numbers for all of them give me a shout (PM)
Pic here - and some more info here -
http://www.galls.com/priority-start-promax-battery-protection-system#.U_DWNMVdWSp