TYLT Energi (left to right) 10K, 5K, 3K, 2K

Four batteries to fit your needs, each with solid design and performance — just be ready to pay for them.

TYLT has made name for itself as a manufacturer that puts out high-quality mobile accessories that are both functional and completely unique in their design. You can usually spot a TYLT case or battery by its sharp lines, soft-touch materials and striking palette of amazingly bright and lively colors. Its lineup of Energi external batteries are no exception, bringing some sleek style along with great functionality and performance as well.

The Energi lineup of external batteries come in a variety of sizes and are simply named to (roughly) indicate their capacity. You have an Energi 10K that is 10,400mAh capacity, followed by a 5K (5,200mAh), 3K (3,000mAh) and 2K (2,000mAh). Each has its benefits and downsides as you go through the range, but you'll hardly be disappointed with any one you pick up — read along and see the merits of the whole range of TYLT Energi battery packs.

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TYLT Energi (left to right) 10K, 5K, 3K, 2K

Looks and features

We've all seen mobile battery packs out there, and while they cover the gambit from small to large and surprisingly cheap to seemingly expensive, it's clear when you get a high-quality product in your hand that it's worth the money. The TYLT Energi line falls into that high-quality camp.

Each Energi battery pack — from the 10K down to the 2K — has a nearly identical design. Most of the battery is a solid slab of super hard black plastic, with a streak of colored soft touch material in a band across the middle. It isn't soft enough to keep the battery from sliding off a table, sadly, but makes it look nice at least. Each battery except the 10K has a single power button that starts the power flow and has an integrated LED that shows the charge status with a simple green, yellow or red light. The 10K steps it up with an array of multiple LEDs to show charge state.

The Energi 3K and 5K have integrated flip-out Micro USB cables that store nicely along two edges of the battery pack and clip into place for when they're not in use. The cables aren't horribly long at about 5-inches, but are just long enough to keep the battery from bashing up against whatever you have it plugged into. They also have a standard female USB port so you can plug in your own cable or even charge two devices at once if you so desire.

The Energi 2K and 10K are limited to using an external cable, although it should be said that TYLT includes a Micro USB cable in the box with each battery that can be used to charge the packs or flip around and charge your phones and tablets. The Energi 2K has just a single USB port, while the 10K has a power-dealing three ports.

Capacity and real-world use

When it comes to actually using the battery packs to keep my bevy of devices charged up, the TYLT Energi line do an admirable job. Let's start with the Energi 2K and work our way up.

Energi 2K: Small and super compact battery, perfect for fitting into a jacket pocket for a quick bump in charge on your phone. The downside is that this battery doesn't have an integrated cable, so you're stuck also bringing your own USB cable — one more thing to carry, reducing its functionality as a small "carry anywhere" battery pack. While using your phone regularly, the 2K will go from full to empty and provide you maybe 25 percent charge on the phone — not quite enough to make it worth it, again.

Energi 3K: This is the sweet spot of portability and power in the TYLT line. Coming in just imperceptibly larger than the 2K model, the 3K offers 50 percent more capacity than the 2K and an integrated USB cable. No carrying of a cable when you slip the battery into your pocket on the way out the door, and there's enough juice to get a good portion of your phone's battery powered back up.

Energi 5K: This pack was clearly designed to be roughly the same size as a modern, large-screened phone. Its footprint on a table is nearly identical to that of a Nexus 5, but is roughly 50 percent thicker. You can hold it in your hand just like you'd hold a phone, and that also means it'll fit anywhere you normally would slip a phone — in an empty jeans pocket, a jacket pocket, purse or bag — with ease. It packs a solid amount of charge, enough to add a quick 30 percent battery to my Nexus 7 in just over an hour, and even take it from 35 percent to full with some charge left to spare.

Energi 10K: Not everyone is going to need this kind of power. If you have the need to keep multiple phones, tablets and hotspots powered up (or you just play Ingress a lot) and don't mind carrying a brick around, then this is your savior. In some impromptu testing I was able to take a completely dead Nexus 7, Google Glass and NVIDIA Shield, plug them into the Energi 10K and give each a sizable charge. Glass topped off quickly and was removed after about an hour, the Shield made it to 40 percent, the Nexus 7 got to 65 percent before the battery pack finally drained. That's a heck of a lot of juice to pump into three devices that were completely dead and then in-use once put on the charger, and you just don't find that in a single battery pack often.

These clearly aren't the cheapest external batteries out there, but they're far higher quality than you'll be getting from those cheap batteries as well. The TYLT Energi line of batteries will keep your devices juiced up no matter the situation, and sometimes it's hard to put a price on that.

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