If there’s one thing our smartphones need more of, it’s battery power. On a recent trip I exhausted my iPhone 5s’s battery by noon. It was partially due to my hotel having poor WiFi and needing to use my phone as a hot spot. But with all the new things we’re doing with our phones — playing games, browsing the Internet, reading books and watching videos — there’s rarely enough battery power to get through the day, particularly with iPhones.

I’ve been trying several products to help alleviate the problem: a power case with a built-in battery and separate battery packs.

Mophie Space Pack: The best solution for those who need lots of power all the time is a battery or power case, such as those produced by Mophie. They come in several sizes and colors, mostly for the iPhone, and a few for Samsung and HTC phones. Their big disadvantage is that they add bulk and mask the sleek appearance of the phone.

I’ve had mixed feelings about power cases for years, disliking them for their added bulk, but appreciating them for eliminating the need to recharge my phone during the day. I’m now at a point where I can’t go without it; I leave it on all the time and no longer worry about my battery running low. They also offer the advantage of not needing to carry anything extra and charging multiple devices.

Mophie’s newest power case, Space Pack, makes it even more useful; it addresses two of the iPhone’s limitations in one product: battery and memory. The Space Pack looks similar to other Mophie battery cases, but is a bit longer and contains 16GB or 32GB of built-in memory. It can store thousands of photos, videos, and tunes, as well as all kinds of files. Think of it as a built-in solid-state drive. I’ve been using it to store important documents that I want to have ready access to, such as presentations, spreadsheets and Word documents.

Mophie Space Pack addresses two of the iPhone’s limitations in one product: battery and memory. Courtesy photo

To use the memory, download the free Space app from the iTunes store. Open the app and press the button on the back of the case and you’ll see six folders with icons labeled Photos, Videos, Music, Documents, Other and All.

You can add content to the folders using email attachments, synching with other apps or plugging into your computer where the memory will appear as a hard drive, allowing you to drag documents from the desktop to the Mophie.

I found the extra storage really came in handy because it addresses one of iOS7’s limitations: the lack of a file system and a way to store documents on the phone. Instead, the iPhone is designed to store documents on the cloud using apps such as Dropbox. Note that the memory in the Space Pack is not integrated with the iPhone’s own memory, but is accessed separately.

The pack’s battery is 1700mAh that nearly doubles your iPhone’s battery capacity. You charge both phone and case batteries with a single microUSB cable and use the on/off switch on the back of the case to allow the case’s battery to charge the iPhone. A row of LEDs tells you the amount of battery remaining in the pack.

The Space Pack costs $150 for a 16GB case, and $180 for a 32GB case. It comes in matte black finish or a glossy white finish. A similar Mophie case without memory and the same size battery, the Juice Pack Air, costs $100.

Ventev battery packs: Separate power packs are another solution. They are basically a large battery in a rectangular box that you charge and then plug into the phone to recharge your phone’s battery. Some packs can double or triple your phone’s battery life offering triple the battery life of the Mophie Space Pack. They can also be used to charge other devices such as Bluetooth headphones, a second phone, and tablets. The downside is they are a bit large to carry around all the time, and it’s another device you need to keep charged.

I’ve been trying out Ventev’s new Powercell 5000 and Powercell 6000+ battery packs, somewhat thicker than a smart phone with a similar footprint. Each has enough power to charge a smartphone almost three times or a typical tablet to about three-fourths capacity. And each has two charging ports, one that provides 1 amp for phones and the other 2 amps for iPads.

The Powercell 5000 is charged using your own USB charger. The larger 6000+ model has built-in folding prongs that plug into an outlet for charging and works as a charger for your devices as well. Each product is handsomely styled and displays their charge level. They’re available for about $45 and $65 respectively at discount. (ventev.com).

If you constantly need more battery power to get through the day, the Mophie power case is your best solution. If you need the extra power occasionally or want to charge multiple devices, then the battery packs may be your best choice.