We already reviewed the 5.7″ Microsoft Lumia 640 XL Dual SIM and it turned out quite light on the battery and thus leading to an excellent endurance rating of 74 hours. That’s the reason we had high expectations for the smaller 5″ Lumia 640, which is based on the same Snapdragon 400 chipset. The Lumia 640 LTE has a 5″ HD display, Snapdragon 400 SoC with 1GB of RAM, and is powered by a 2,500 mAh battery. It runs on the latest available Windows Phone 8.1 with Update 2 and Lumia Denim, just like the XL model. The Lumia 640 did great on our 3G talk time call test lasting few minutes north of 23 hours. The Lumia 640 XL did about 6 and a half hours better, but it has a beefier 3,000 mAh battery. Talk time Sort by Label Sort by Value Expand Samsung Galaxy Tab Pro 10.1 LTE46:44h Apple iPhone 6 Plus23:49h LG AKA23:20h Sony Xperia Z323:13h Microsoft Lumia 640 Dual SIM23:09h Microsoft Lumia 640 LTE23:09h Microsoft Lumia 640 LTE23:09h Samsung P6200 Galaxy Tab 7.0 Plus22:42h Motorola Moto E (2nd gen)22:36h Huawei MediaPad 7 Vogue22:16h Nokia Lumia 132022:13h Samsung Galaxy Core LTE22:13h Pantech Burst4:46h The web browsing endurance turned out as impressive as on the Lumia 640 XL – the 5″ Lumia 640 battery went dead after 10 hours and 23 minutes. This meansthe screen of the Lumia 640 and its IE browser as very energy efficient. Web browsing Sort by Label Sort by Value Expand Huawei Ascend Mate2 4G16:41h Motorola Moto G 4G10:52h LG AKA10:38h Nokia Lumia 83010:36h Apple iPhone 610:29h Meizu MX4 Pro10:24h Microsoft Lumia 640 LTE10:23h Microsoft Lumia 640 Dual SIM10:23h Microsoft Lumia 640 LTE10:23h Nokia Lumia 63010:18h Microsoft Lumia 640 XL Dual SIM10:14h Microsoft Lumia 640 XL LTE10:14h Samsung Galaxy Nexus I92503:01h Spending long hours of watching movies won’t be a problem either, as the Lumia 640 is capable of sustaining almost 10 hours of non-stop playback before its battery drops down to 10%. Video playback Sort by Label Sort by Value Expand LG G Flex19:57h HTC Desire 5109:54h Nokia 808 PureView9:53h Oppo N39:49h Alcatel Hero9:49h Sony Xperia M9:49h Microsoft Lumia 640 LTE9:43h Microsoft Lumia 640 LTE Dual SIM9:43h Microsoft Lumia 640 Dual SIM9:43h Samsung I8530 Galaxy Beam9:42h Samsung Rugby Smart I8479:34h Meizu MX49:31h Nokia Lumia 7103:27h The Lumia 640 outed slightly above average standby score at 11 days, which combined with the other scores helped it achieve and excellent endurance rating of 76 hours. This means it will last three days if you do an hour each of watching videos, browsing the web and making calls each day. Note that we tested the LTE-enabled, single-SIM version. However, the Lumia 640 XL Dual SIM showed no noticeable difference in standby power draw with one or two SIM cards. Our routine also includes a standby battery draw test, which is not featured in our battery test scorecard but is calculated in the total endurance rating. Our battery testing procedure is described in detail in case you want to learn more about it.