There are a ton of in-car devices chargers on the market, some of them great, some not so. But we particularly likes ones which add a little bit extra functionality to the mix, to deliver better value for your buck.

This Cup Holder Battery Tester Power Station fits into any standard car cup holder block, and offers twin USB sockets to charge up your phones and/or tablet computers. So far so normal. But the extra coolness comes in the form of a bank of indicator lights which tell you what the state of your car battery is at any one time.

This means that you can keep tabs on your vehicle’s battery while you’re charging up your gadgets, especially useful if you’ve got the engine off (at which point your battery is rather vulnerable to too much drain). It’s a simple thing, but useful. Priced at $14.95.