
I think you may well find that a cordless vac may not be up to the job of cleaning after very hairy dogs, especially when they moult (I have a golden retriever and know all about moulting

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We have a Dyson cordless which I use at the static. We don't have mains electrics at the static, having solar panel, battery's and an inverter to obtain 240v, but not enough to run a mains vacuum. I found the Dyson cordless good, but not that good on the carpet. Goldie hair seems to weave its way in and I needed to go round with a rubber headed brush to bring the hair out of the carpet then Hoover it up. So, having had enough last year, got the carpet taken out and now have a good quality vinyl down. Not so warm underfoot, but it saved my sanity.
I've had Dysons for years and recently got a Dyson animal which I find really good. I did consider changing and the Meile is often recommended.