There are many things I’ve learnt to distrust over the years. PRs who start a conversation with the phrase “have you got 30 seconds?”, my Dad’s woefully optimistic assessment of the carnage he’s unleashed on his PC, and West Ham’s back four, for instance. But none more so than the battery indicator on mobile phones.

They are pathological liars. They’ll spend two days displaying five full bars of battery goodness, only to chomp their way through the remaining bars in six-and-a-half minutes. I’ll never buy a Sony Ericsson phone again after the time I left the house with the full five bars of battery, only to end up on the motorway hard shoulder a couple of hours later, barking instructions to my girlfriend in a demented verbal shorthand, because the battery had inexplicably drained down to the last sodding bar.

And what does the phone do when it’s approaching battery Armageddon? Does it go into Apollo 13 mode and start shutting down every last unnecessary amp of power? No, it starts twittering out “battery low” warnings like a budgie on Speed, serving only to chip another few seconds off your remaining talktime in the process.

That is until the Nokia E71 arrived. You may be aware of others, but this is genuinely the first phone I’ve ever owned where the battery indicator actually indicates how much battery life is left. This became gloriously apparent on Friday night, when my train decided to take an unscheduled stop somewhere between Three Bridges and Haywards Heath. For an hour-and-a-chuffing-half.

The train driver is probably right now being head-hunted by the SAS, because if this chap was dropped behind enemy lines and taken prisoner, there’s no amount of nipple-tweaking torture that could persuade him to start talking. Thus, I headed over to the BBC Travel website to find out what the problem was, and then sent a succession of SMS progress reports to my girlfriend, all with my battery indicator dangling on a single precarious bar.

I even managed to fire up the GPS and find out exactly where I was marooned, and read a few angry comments on Twitter from fellow commuters. Indeed, the phone was still perky when I arrived home some three hours later.

So battery indiciators have stopped lying to us. Perhaps, Microsoft can headhunt the person responsible and set them to work on Windows’ progress bars? 

My esteemed editor recently handed me the Nokia E71 he’d been testing. Because he’s a stickler for reviewing kit properly, it was stuffed full of his personal data, including his Exchange email, text messages and contacts.

Once I’d sent an email to our publisher with Tim’s recommendation of a huge pay rise for the hard-working, irreplaceable, online editor, I set about trying to wipe the data.  First, I formatted the memory card, but it seems all Tim’s personal files were stored on the phone’s internal memory and, oddly, there was no obvious way to format that.

So I dug out the manual and hard reset the phone to factory settings, but incredibly that wasn’t enough to shift the data either.   Which means either Nokia is pre-installing the personal data of PC Pro staff on all of its handsets or the hard reset is about as hard as The Sun crossword.

In the end, I resorted to deleting the data manually from each of the relevant folders. And it seems I’m not the only one who has trouble scrubbing data from Nokia devices. “It has taken us over a year to get talks going with Nokia that now allows us to wipe their phones,” said John Godfrey, from mobile recycling service, Sims Lifecycle Services, talking to The Guardian.  “To wipe it, you have to be able to access all the memory – and manufacturers don’t want you to do that for all sorts of commercial reasons.”

That’s plainly not good enough. Mobile phones are probably more recycle-worthy than any other gadget, because the networks tempt customers to upgrade long before the phone ceases functioning. But there’s no way consumers, and especially businesses, will send their phones to be reused if there’s any chance their sensitive data will go with it. Even my manual delete wouldn’t prevent a determined hacker from retrieving infromation from the phone’s memory. 

Instead of adding barcode readers, novelty wallpapers or all manner of other useless gubbins on our handsets, the phone makers should be working on a simple way to erase user data. It can’t be that difficult – Windows does it without even trying!