May work on a battery just below the charge needed to start a RR but a completely flat/dead battery then no chance. (IMHO)

Mr Tee wrote:

Sorely tempted, got another electrical drain, due to leave the car at the airport, either this or one of the solar chargers from Maplin. Car was completely dead in November after 1 week, battery has been replaced within the last 1.5 years, the joy continues.

left mine 2 weeks in august manchester airport ,solar charger plugged in was so dead could only unlock the drivers door , also AA mans jump starter wouldn't do it had to be jumped off his van after about 10 mins charge ,
just can't see that little battery jumping a FFRR.

If you were to fit a battery isolating switch to your car you could leave it as long as you like at an airport etc and the battery would be fully charged when you came back.
Providing of course there was no internal fault in the battery causing a drain.... highly unlikely.
After switching the battery off, the car could be locked and unlocked using a key, the old fashioned way.
The car wouldn't be alarmed whilst locked but you have to chose a functioning alarm or a dead battery on return.
This obviously means your car has to have a key operated drivers door lock and that it works reliably every the time.
Isolating the battery means that should the worst happen and your door lock fails you would have no means of getting into the car unless of course you arranged to fit the battery isolating switch in an accessible position.
Although most battery isolating switches tend to incorporate a fused bye-pass circuit to allow the alarm to operate whilst the battery is isolated, this would have to be disconnected otherwise any battery drain on the car would simply carry on resulting in a flat battery as usual.
An alternative would be to carry a spare fully charged 110AH battery and a set of jump leads in the car when doing the airport thing.

I got one of these for Xmas from my Grandfather after he'd seen them advertised in a Sunday paper supplement.
I'll keep it in the car just in case!!

Boxes of Snake Oil if you ask me.
And if you dont ask me I will tell you anyway.

Adrian VW Amarok 2014 Highline auto

I bought one of these mainly as a long life power supply for my laptop and phone.

I went out to my old tractor the other day and it wouldn't start, It would turn as far as compression but not past. I decided to try the little boost pack on it before trudging round the farm looking for the jump leads and much to my surprise it started up no problem. the cables from the pack got pretty hot though.

All in all im impressed with it. Oh and just incase your thinking it was a little petrol fergie, the tractor in question is a County 1174 fitted with a Ford 6.6L dieasl.

Stew

they work then....

Saw this video on YouTube starting a car with capacitors. Maybe it is the same science behind it.

 Tom

Current Drive
2011 4.4 TDV8 Autobiography - Santorini Black - Ivory Leather

Previous Drives
2004 Model Vogue Td6 (Touchscreen) - Java Black - Parchment Leather
1994 RR Classic 3.9 V8 Soft dash - Niagara Grey - Grey Leather
1972 Series III SWB Safari - Green (Hand Painted) - Black Plastic