Motorola DROID RAZR HD MAXX ad says "Long Live the Battery!"
with just a small bump in girth. The result was a LTE connected Android phone that could last all day on a single charge. The official word was 21 hours of talk time was possible with the Motorola DROID RAZR MAXX and the device became so popular that some analysts checking sales data said it was outselling the Apple iPhone 4S at Verizon earlier in the year.
But things appeared to be different with the Motorola DROID RAZR HD. Considering the high capacity 2530mAh battery on the device, it was somewhat surprising that a "MAXX" version was considered to be necessary. But as Android users have discovered, every additional second of battery life that can be added to a model running LTE must be embraced. Thus, the Motorola DROID RAZR MAXX HD was born.
source: Motorola via Phandroid