Boost Case Plus

The Boost Case Plus provides the best insurance against running out of power during an intense day of smartphone usage. The case has the largest capacity battery of any of the iPhone battery cases reviewed in this roundup. At 2200 mAh, the Boost Case Plus's battery easily kept my iPhone 4s running for more than a day, even under heavy usage. The Boost Case Plus isn't svelte, but it is barely heavier and bulkier than its 1700 mAh sibling, the Boost Case and the uNu and RichardSolo cases.

The front and sides of the Boost Case Plus are a smooth matte silver plastic while the back is basic black. A perfectionist may object to the faint wrinkling of the plastic around the various cutouts for the volume controls, headphones and so forth, but it will be barely noticeable to most people. On the back of the case are a power button and four status LEDs. Tap the button to see how much capacity is left. Hold down the button for a couple of seconds to toggle the battery on and off.

Like many of the other cases that we looked at, the Boost Case Plus consists of a large bottom portion that contains the battery, 30-pin connector and microUSB socket and then a small connecting cover for the top of the phone. All of the iPhone's controls were easily accessible through the case. I was able to plug in the standard iPhone headphones without a problem but I couldn't plug in my other 3.5mm connectors without removing the case’s top plate.

I put the Boost Case Plus through a fairly grueling test, using my iPhone 4s with the (free and excellent) Waze GPS application to navigate me down I-95 over the Thanksgiving holiday weekend while streaming Pandora the whole way. When I wasn't in my car, I was doing my usual constant emailing and surfing. By the end of the evening the Boost Case Plus' battery had run out, but I had enough juice left in the iPhone to make it through to the next morning. When my wife used the case with her iPhone 4 she still had 47% battery left in her iPhone at the end of two days of light smartphone usage.

If you don't have a problem with a case that adds some bulk to your iPhone, the Boost Case Plus is worthy of serious consideration. The large capacity battery is a fair tradeoff for the negligibly negligible increase in size and weight over the 1700 mAh battery cases.

Name: Boost Case Plus

The Boost Case Plus has the biggest, longest-lasting battery we tested. Despite some bulkiness, it's the case of choice for those whose top priority is to maximize battery life.

Price: $79.95
Capacity: 2200 mAh
Pros:

• Big, long-lasting battery

Cons:

• Bulky
• Case edges show imperfection
• Some peripherals can't connect with case on

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