Hmmm.......I can find nothing about the refrigeration specifications of that particular Dometic model, it justs boasts clever electronics in the sales pitch. Its one of the units I am skeptical about.
I wouldn't be interested in its heating function unless I spent time outdoors in winter, how much hot food or soup does one man need ??... (buy a cheap thermos flask or a camping stove if you want heating! ).
The Dometic states max 27 degrees below ambient, which suggests to me either it is not a compressor unit or is so small its performance falls off in high ambient conditions rather than being adequately sized to cope.
The Halfords is specified to work down to -22 degrees so can run as a proper freezer as well as a fridge, unlike the Dometic. It runs on the latest refrigerant R1234YF so is definitely a compressor unit working on the "vapour compression cycle", which is what you want for performance.
On a (rare) 40 degree ambient day you will be drinking warm beer with that particular Dometic and proper cold beer with that Halfords. With that Dometic unit your ice blocks would melt on a warm day, as would your ice cream and your meat would defrost.
Based on a combination of price/performance/physical size/warranty I would almost certainly buy the Halfords cooler if I was in the market for one. Don't be put off that its Chinese made, they all are. (Fridge used to be all Italian stuff but they cant compete with the sheer economy of scale of Chinese production now.)
Whatever unit you decide to buy, get the biggest physical size you can fit/carry/afford as you soon fill these things up, especially with bottles and cans in hot weather. (Top Tip: try to pre-chill stuff overnight in your home fridge before loading the cool box, save it running its nuts off to cool stuff down.)
Some units use a power brick for 240V, some have a built-in transformer..... Pro's and cons to each, but an inbuilt transformer will warm the unit plus if it fails its harder to replace, unlike an external power brick. The Halfords power brick is £15 and can supply 5 amps at 12V. The Halfords Advanced coolbox is 50 Watt, so 4.2 amps at 12vdc.
Looking online, there are also some good refrigerated cool boxes from Outwell.
www.outwell.com
