Since no one with experience with the DGT2010 has answered, I'm going to hazard a guess and say that your experience with battery life is not typical, but is probably due to a faulty individual clock. I own the DGT North American, which I think has almost identical hardware to the DGT2010, and have never experienced the battery drain you are talking about.
I see that your question is almost 5 months old, so you have probably already resolved it one way or the other. So I'd like to hear what you found out.
I'm currently looking for a chess clock and a sports store in Dublin gave me a loan of a DGT2010 for a few days. Apparently a couple of people have already purchased it and returned it as it "eats the batteries", despite the fact that the manual claims it should run for up to 10 years on one set. So I had a very basic look at the problem:
It runs best on AA alkaline batteries, but all AA alkalines that I know of are slightly thicker than the zinc chloride ones. On zinc chloride batteries the battery life is immediately displayed as low, even though the batteries are new.
On alkalines (I put in a new pair of Duracell) the clock starts fine but shorts after a couple of minutes, or if it's knocked, as if the slightly wider batteries don't make a secure contact. I have the zinc chloride ones back in now and currently have the clock running to see how long it takes for the "low battery" warning to run to empty.
In the meantime, has anyone had an experience like this with the DGT2010? Is it likely that the specific one sitting beside me now is simply faulty? And what clock would you guys recommend? I don't NEED the FIDE approved clock - it's all the store had - but at the same time I don't want a shitty looking clock, like the plastic analog ones. I'd actually prefer a digital clock, and preferably a sturdy one!