For many of us, the most important characteristic of our phone is its battery life. After all, what's the use of the latest and greatest features if your phone stops working in the middle of something important?
More processor cores and camera megapixels are great, but unless you're planning on investing in - and regularly charging - battery packs, you might want to pay some attention to the battery life too. There are some new phones that really embody this concept, such as the Wickedleak Wammy Titan 4, with a 5,330mAh battery, which launched a few weeks ago.
The Lava Iris Fuel 20 also launched just before that, and comes with what is possibly the biggest battery in the sub-Rs. 6,000 range. We haven't reviewed those two yet, but if you want a phone with great battery life, there are plenty of other options we've already tested.
Here are our best performing phones with the best battery life across different price bands.
Under Rs. 5,000
The Nokia Asha 502 is probably the best phone you'll get under Rs. 5,000 and its 1010mAh battery keeps going for really long. It isn't taxed by high-end components; it has only a 3-inch 240x320 display and just 64MB of RAM, but its design is good and if you're looking for a basic device then this is not a bad option.
Under Rs. 5,000, you could also check out the Maxx Mobile MX200 (Review). We can't honestly recommend that phone as anyone's primary device, since the only good thing about it is its 5200mAh battery. You could think of this phone as a portable battery that lets you make calls.
Under Rs. 10,000
There are more options in this price bracket, but in the end, we'd recommend the Lava Iris Fuel 60 (Review | Pictures), which you can get for just under Rs. 9,000. This 5-inch phone has a large 4,000mAh battery that keeps it running for a long time. The 720x1280 display, powered by a 1.3GHz processor alongside 1GB RAM is nothing special, but the performance is not bad, and the software loaded on it is relatively free of bloat. The camera could be better, but again, we're not complaining at this price level.
If you want to spend a little less and are willing to compromise on the camera as well as the Android app ecosystem, then the Windows Phone-based Nokia Lumia 630 Dual SIM (Review | Pictures) is an alternative. It costs less than Rs. 7,000, and has good build quality. Its relatively small 1830mAh battery nonetheless kept the phone running for 11 hours in our non-stop video playback test.
Under Rs. 15,000
Lots of competition in the Rs. 10,000 to Rs. 15,000 range in terms of long-lasting batteries in phones, but in the end, our winner is the Nokia Lumia 730 Dual SIM (Review | Pictures). Its good design, display and camera along with excellent battery life make this the right choice if you're not set on getting an Android phone. The phone went on for 12 hours and 44 minutes in our video loop test, which is excellent, and if you're not strongly entrenched in Android then this is a good option for the price, even setting aside battery life.
If you absolutely need an Android phone then all the different options out there come with some compromise at this price point. We would go with the slightly more affordable Micromax Canvas Nitro (Review | Pictures). The phone comes preloaded with lots of unnecessary software and the camera is quite disappointing, but the display and performance are not bad, and the battery kept going for 16 hours and 9 minutes in our video loop test.
Under Rs. 20,000
Between Rs. 15,000 and Rs. 20,000, the best phone to go with if you need a long battery life is the Sony Xperia C3 Dual (Review | Pictures) - this 5.5-inch phone has a 720p display, a 1.2GHz processor and 1GB of RAM. It also has an 8-megapixel rear camera. Its display, and camera both do good jobs. There's nothing that really stands out, but it consistently delivers a good experience, and the 2,500mAh battery keeps it going for nearly 14 hours when looping video.
The Lenovo P780 (Review | Pictures) could well be credited with starting the trend of extra long battery life in smartphones, and with price cuts, it is now a little cheaper than the Sony Xperia C3. Its 4,000mAh battery lasted 16-17 hours with medium to heavy usage. However, it falls a little short in terms of design, display and camera, which is why we would recommend you go with the Sony.
Under Rs. 30,000
Over Rs. 20,000, you see more phones that have great batteries without too many compromises. Our pick is easy - the Sony Xperia Z1 Compact (Review | Pictures) - this phone scored very well in all our review categories except for the camera, which still got a 7 on 10. Solid battery life is matched by a sleek design, display and performance.
The less expensive Samsung Galaxy Neo is an option if you are trying to keep the price down, but the camera is mediocre and graphics performance is poor, so don't plan on this phone for gaming sessions. The S-Pen and long battery life do potentially make it a good choice for workaholics though.
Under Rs. 40,000
Between Rs. 30,000 and Rs. 40,000, the choice is really between the Sony Xperia Z3 Compact (Review | Pictures) which is nearly Rs. 40,000, and the Samsung Galaxy S5 (Review | Pictures) which is selling at just over Rs. 30,000. The Samsung has the edge in its display, camera and performance in our review, but the Sony edges it out on battery life, running 3 hours longer on our looped video test.
A mention has to go to the LG G Flex (Review | Pictures) - the curved phone was launched for nearly Rs. 70,000, and is now available for approximately Rs. 35,000. Its display and camera both rated poorly, which is why we would prefer the other two phones instead, but if you really want a curved phone, the new price is tempting.
Over Rs. 40,000
Once you cross Rs. 40,000, choices narrow again. We think that the only phone you should seriously consider if battery life is the prime concern, is the Samsung Galaxy Note 4 (Review | Pictures). Launched with an MRP of Rs. 61,500, the Note 4 is now available for just over Rs. 50,000, and while its gaming performance is a little below what you might expect, it has a fantastic screen, powerful general performance, outstanding battery life, and the S-Pen adds a lot of functionality.
Otherwise, you can consider the BlackBerry Passport (Review | Pictures) but some will find it awkward to hold, and Android app support is not guaranteed. The iPhone 6 Plus (Review | Pictures) offers better battery life than its smaller counterpart, making it an option as well. If you want the latest and greatest, then the Samsung Galaxy Note Edge (Review | Pictures), which costs nearly Rs. 65,000 is the phone to buy, but it doesn't feel like as much value for money as its non-curved counterpart. If you're buying a phone that will keep working while you're working around the clock, then the Samsung Galaxy Note 4 is the one we would pick.
Are you going to pick one of these phones for yourself? How do you plan to use that battery life? Tell us via the comments.