Yep access, good idea to check the antifreeze properly but the voltmeters to check the state of the battery don't tell the whole story. Most good battery sellers should have a "Drop Tester" which does a more reliable test on the battery and shows how it is likely to stand up to the greater drain on it's resources during the winter season.
By the way, for anybody buying a replacement battery for a car they intend keeping for 5 years or more during which you would probably exchange your battery twice, there is a replacement called an Optima battery (red top for normal car/SUV use) They throw out far more cranking power to start the vehicle and seem to have a life expectancy of on average 8 years even in hot climates which destroy batteries much quicker than the UK's temperatures. Optima do cost more but save on breakdown times and costs. (no, I am not an agent for Optima guys!)