Cordless vacuum cleaners are great aren't they?! The only drawback is that they charge for quite a while, but only last for around 15 minutes or so. This is fine if you live in a small home, but a larger home would probably benefit from a normal vacuum cleaner - perhaps a lightweight one. Vacuum cleaners tend to be the worst part of house cleaning, because they weigh so much, particularly if you're going up and down stairs!
I use a Vax U91MAB, which I found using a comparison website specifically for lightweight vacuum cleaners: www.lightweightvacuumcleanershub.co.uk
I've had it for 6 months and it's been bliss. There are also some Dyson models that are very light, BUT they are hugely expensive!
You could buy a cordless/hand held vacuum cleaner for those little spills or to spruce up the place before visitors arrive, but I wouldn't use one for cleaning your home top to bottom as the machine probably won't last that long.