Image copyrightMotorola

Motorola has announced its second generation Android Wear smartwatches.

There will be two versions of the Moto 360, one of which will have a GPS location chip to help the collection of fitness tracking data when the device is not linked to a phone.

The firm will also allow shoppers to customise the device's design when they order it - a facility it already offers for its smartphones.

But one expert said the product might struggle to stand out from rivals.

"The Moto 360 was strikingly distinctive last year because of its circular screen - it was the only leading smartwatch with that look," said Ian Fogg, from the research firm IHS Technology.

"This year virtually every smartwatch-maker has a circular device except Apple.

"The software Google provides is tightly controlled and almost identical on every Android Wear watch.

"So, the only way you can differentiate today is with hardware, and the problem is that everyone copies it."

Motorola unveiled the new devices at the Ifa tech show in Berlin. Prices will vary by design, starting at £229, when they go on sale later this month.

Earlier in the day, Huawei announced its own circular Android Wear Watch would go on sale in a fortnight starting at $349 (£228).

Samsung is also at Ifa with its forthcoming Gear S2, a circular watch that runs on Tizen rather than Android, whose price has not yet been revealed.

Only Asus bucked the circular design trend with the announcement of its square-faced ZenWatch 2. The lowest-cost version will be 149 euros ($167; £109).

'Flat tyre'

In addition to allowing customers to decide the colour, materials, bezel style and type of strap or wrap band included, Motorola now offers the devices in two sizes: 46mm (1.81in) and 42mm (1.65in) faces.

It is also hoping to distinguish its products by introducing Live Dials - a feature on the Moto 360's watch face that acts as a shortcut to the owner's favourite apps.

The company is also promising longer battery life than before - something for which the original version was criticised.

The company said the devices would now last "up to two full days of use", which would be above the norm for such wearables.

Unlike Sony's Smartwatch 3, Motorola's wearable is not classed as being waterproof, so should not be taken swimming.

However, the Moto 360 Sport edition contains a GPS chip to track vital signs, speed, distance, and pace, and features a screen that is easier to read under sunlight. The trade off is that the model is slightly bulkier and will be more expensive than the standard version.

One change Motorola was unable to make was to get rid of a black band at the bottom of its screen where the LCD display drivers and ambient light sensor are based.

Other smartwatch makers have avoided the issue by using thicker bezels and/or not including the sensor, which means their screens do not automatically adjust their brightness.

"The active area of our screen size is about 70 to 75% of the overall size of the device," Motorola executive Kouji Kodera told the BBC, explaining the design choice.

"If you compare that to the competition, they are in the range of 45 to 50%.

"So, their devices are much bigger than the screen sizes that they have, which is an important factor for a wearable device."

But Mr Fogg said the resulting "dead zone" was regrettable.

"I think the 'flat tyre' look is an irritation that damaged the clean design lines of the original Moto 360," he said.

"But I think it's more important that the firm is now offering improved battery life, a faster processor - though not one optimised for wearables - and new activity tracking features."

Brand builder

The original Moto 360 was 2014's bestselling Android Wear device, according to research firm Canalys.

However, more recent data from IDC indicates that the Apple Watch has sold in much larger numbers, and Motorola did not make its top five list of wearable tech manufacturers for either of the first two quarters of 2015.

The new Moto 360s will benefit from the fact they can be paired with iPhones, unlike the first model.

But Motorola and its rivals still have to convince smartphone users that they need such devices.

Even so, Mr Fogg suggested the two new watches should still prove valuable to the business, which is owned by China's Lenovo.

"Motorola's challenge is that its business has shrunk hugely since the heyday of the 1990s, and it takes a long time to rebuild brand awareness," he explained.

"And the Moto 360 has already helped revitalise the brand - showing that it is innovative and modern - more than any other recent Motorola product."