Battery Life

I still think that when we’re reviewing a 4G LTE device that battery life is the main concern, and with a sealed internal battery this is an even more relevant point than it would be otherwise. I started the Bionic review out with a look at battery life first, and think the same approach makes sense for the RAZR. As I mentioned before, the RAZR has a 6.7 Whr internal battery which makes use of Motorola’s new higher voltage Li-Ion chemistry, just like we saw in the Bionic.

Motorola also sent us all the goodies to go along with the RAZR, including the Lapdock 100, car windshield mount, VGA adapter, and an extra external 6.9 Whr battery. More on those accessories in a moment, for now let's just talk about the battery.

Since the battery for the RAZR is sealed inside, there’s no way to go the traditional extended battery route, and thus this external battery which connects using microUSB is the only viable option to extend your electron tank. The external battery charges using a microUSB port on its side and can charge up to two devices at the same time.

One using the microUSB connector on a rubberized cable that folds into the opposite side, the other using the female USB type A connector at the top. I used the external charger to juice up the RAZR and another device at the same time to much success. Of course, using a big external battery to simultaneously charge a battery and power the RAZR incurs some overhead.

To measure how good the RAZR is at sipping juice, we turned to our standard suite of battery life tests. The first loads through a dozen or so pages over cellular data and WiFi with the display constantly on and set to a brightness of 200 nits using the stock browser.

Web Browsing (Cellular 4G WiMAX or LTE)
Web Browsing (Cellular 3G - EVDO or WCDMA)

In the cellular browsing department, the RAZR unsurprisingly performs very close to the Bionic, but comes in just behind in spite of having a slightly larger battery. It’s pretty easy to point out the sources of increased battery drain on the RAZR versus Bionic, and that’s both inclusion of AMOLED (virtually all the webpages in our testing suite have white backgrounds), and a higher CPU clock, though admittedly most of the time the CPU is in an idle state. The other parts of the equation again remain the same - the RAZR has the same cellular basebands and a similar family PMIC (power management IC).

Using the external battery gives you another 2.5 hours of charge in our LTE test, which isn’t a doubling, but still a respectable boost. As predicted, you end up losing some of that charge on the external battery to overhead, but it isn’t dramatic. I didn’t measure how much of a gain using the external battery on EVDO nets you, but you can safely bet the same 1.83 multiplier applies.

Web Browsing (WiFi)

This trend where the RAZR lags the Bionic in our battery life testing carries on to the WiFi web browsing test as well - the two include the same TI WL1285 WLAN combo chip.

Cellular Talk Time

Call testing time likewise puts the RAZR just behind the Bionic. As a reminder, calls on Verizon still happen over 1x on the MDM6600.

I’m starting to put more stock in our WiFi hotspot battery life test, which has four of our normal page loading tabs open and a 128 kbps MP3 streaming radio instance from going. This keeps the baseband and WiFi stacks up and also relies on the CPU for routing network traffic through a NAT, and the display is off.

WiFi Hotspot Battery Life (4G)
WiFi Hotspot Battery Life (3G)

Here the RAZR surprisingly ousts the Bionic (despite testing being done in the exact same location and signal characteristics) by a little over a half hour.

So in the battery department there isn’t much to talk about with respect to the RAZR except to note that it’s very comparable to the Bionic owing to - again - being based on essentially the same hardware platform. The difference we do see is largely a result of adding a Super AMOLED Advanced display and higher peak CPU clock.

If you’re not near a charger or unwilling to go for the external battery, our guidance remains much the same as it did when we first started looking closely at 4G LTE handsets - wait for 28nm SoCs and basebands in 2012. That said, it’s absolutely possible to make it through a day with the internal battery, it just depends on what your daily use patterns are.

Hardware and Physical Impressions Software - Android 2.3.5 and Blur 6.x


View All Comments

  • sjprg2 - Monday, December 19, 2011 - link

    The hands free bluetooth implementation is broken in the sense that it no longer announces whom the caller is. Every previous Motorola phone I have owned tells me who is calling.
    Califorina has a handsfree cellphone law and it is very important that I know whom is calling before I answer in the car in freeway traffic. Business calls I may answer, personal calls can wait. This is a deal breaker! I'm stuck with this until they fix it but I am damed unhappy and if I had known I would not have purchased it. It is more of a toy then a useful phone, granted an atractive toy, but still a toy.
    Does the Apple 4S bluetooth work?
  • QQBoss - Tuesday, December 20, 2011 - link

    I am living in China, and trying to purchase the 4G version of the Razr (unlocked, of course, or at least unlockable). The Chinese version is the XT912, and does not have 4G support (which makes sense, since China doesn't have a 4G network yet). I travel back to the USA periodically, so having 4G for when I am not in China is worth something to me. I have heard said that the non-USA versions of the Razr might have 4G locked off, so this worries me.

    I found an XT910 brought in by grey market here, but I noticed some things that seem off: 1) it only says Razr, not Droid Razr (so it is probably not the USA version of the phone, I think it was from Singapore) 2) No documentation indicates whether or not it supports 4G, and it doesn't ship with anything other than a basic charger (if there was an external 16 GB microSDHC, it was removed by the seller) 3) Under the different networks supported in the menus, I find one that says "other" with no explanation (could be 4G, but since China networks don't recognize it, it doesn't register?).

    I don't care about the lack of the SDHC, I will get a 32 GB class 10 anyway, and chargers are cheap here, but spending roughly US$500 and not getting the actual phone I want seems like a bad option- there are no refunds for grey market. Unfortunately, I didn't write down the baseband ID number. Anyone have a guess?
  • introiboad - Tuesday, December 20, 2011 - link

    Worth mentioning that the RAZR is the second (after the 4S) phone to include support for BLE. Instead of waiting for Google to get their act together and add a standard API to Android, Moto has bundled its own stack (provided by a third party) along with a set of APIs.
    This makes for very interesting applications such as key fobs, hear rate monitors and many others.
  • dj christian - Thursday, December 22, 2011 - link

    What is BLE? Reply
  • doobydoo - Tuesday, January 17, 2012 - link

    It says what it means in his post title, 'Bluetooth Low Energy' - basically it's Bluetooth 4.0.

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