I only drive this car on weekends, and if I have only done short journeys there is a risk of a flat battery. This happened to me two days ago, and standing on a street in the cold waiting for roadside assistance I resolved to buy a booster pack (A new battery would be a good idea too but this one is not that old, and one of these booster things would be much easier to keep charged than either taking my battery out every few months, or running a charge cable from my house to my car, which isn't usually possible to park near enough to my house)
I was looking at the "Sealey RS131 12V 900A Emergency Power Pack" on Amazon, and at least one of the question answerers said he was able to start a 3 litre merc with it. But another one said don't trust it for anything over 2.5 litres, and mentioned the "Clarke 4000 Heavy Duty Jump Start Engine Jump Starter" ("1500 amps peak output / 700 amps boost at 12v")
I don't really understand what the numbers mean. Is there a recommended minimum volts, amps for jump starting this particular 3 litre petrol engine?
(On a side note, the roadside assistance guy first tried his booster on my car - didn't work, ended up having to hook up his van at the same time as the booster to get the car started, but to be fair it was probably very flat, I had in desperation been trying it over and over again before he arrived, which probably drained it further. Add to that the fact my car is like a human having a stroke - windows wind down, alarm goes off, etc when the battery is low - all contributing to draining it further.)