Gadgets to get better battery-level readouts

Current devices suffer from misleading battery energy readouts because they typically measure only voltage. But batteries' output voltage drops when more load is put on them, which is the reason for the sudden plunge on taking calls - even though, in fact, it's unlikely that energy is being depleted so fast.

Furthermore, the voltage behaviour of a battery changes as it ages, which can lead power-management software to erroneously decide that there is no power available much too soon. In many cases, devices shut down well before they need to, and batteries with useful service life remaining get discarded.

"You can lose 30 percent of the energy in a battery simply because the device shuts itself down too early," according to Texas Instruments' engineers.

But the TI battery boffins reckon they've got the answer. The firm has produced a new battery-monitoring chip that measures impedance as well as voltage, allowing a more accurate assessment. The TI designers reckon their kit can tell within 1% just how much energy remains, perhaps allowing an increase in useable capacity of 50 or even 100% - dependant on power-management configuration, of course. The chip can be put in a device such as a smartphone, or in the battery pack itself.

According to TI, their new gear would allow a phone to tell users exactly how much talk or standby time was left, perhaps down to the minute.