TYLT S4 Energi Sliding Power Case Review

TYLT S4 Energi Sliding Power Case Review


The TYLT Energi Sliding Power Case for the Samsung Galaxy S4 is a case with built-in 2350mAh battery which can significantly extend your overall battery life.

On opening the Energi packaging you are presented with a standard micro-USB cable and not one case, but three. There’s a choice of two slim-line plastic cases (one coloured and one black) which have a slit along either side so they can slide securely into the third black battery case. The idea is that you only add the extra weight and bulk of the battery case when you actually need it.



Build Quality & Design

Build quality is top notch, with quality durable plastics used throughout. The inner cases cover the corners, back and sides of your phone while leaving the top and bottom edges exposed. This was obviously necessary to allow you to slide it all the way in to the outer case. With everything fitted, only the top edge, buttons (thankfully) and screen are exposed.

The battery case has an up-side down micro-USB port (compared to Samsung) at the bottom left meaning you will be unable to use it with a Samsung dock.

Looks wise I think TYLT have done a good job with the design of this case. Considering you’re adding a bulky battery to the back of your phone, the Energi looks pretty trendy – especially with the blue inner case fitted.




The S4 comes with a 2600mAh battery, so although an additional 2350mAh won’t double your capacity it does add to it considerably. The Energi delivers a quick 1A charge and in testing I found that a fully charged case would add around 70% to your S4 battery level (with screen off) in around one and a half hours.




The battery case has a button at the back which when pressed lights up red, blue or green to indicate the charge level. Holding the button down for a couple of seconds starts or stops the case delivering charge to your phone.

When plugged in to electricity the case gives priority to your phone, charging it up first before taking any current for itself. The case can also be charged separately.


In Use

Using one of the inner cases adds virtually no weight or bulk to your phone, but does give more grip and a better feel than the smooth plastic S4 back.  There is a tendency to show fingerprints as you may notice from some of the screenshots.  The compromise of the design is that the thin plastic only delivers minimal protection for your phone. It will prevent scratches and scuffs but I wouldn’t feel confident about dropping my phone, especially as the top and bottom edges are exposed.

When battery life starts to dwindle, the slim-line case slides easily into the battery case. This adds to the bulk and weight of your device, but the phone feels more solid and has even better grip than with just using the inner case. Unfortunately the menu and back keys are no longer at the very bottom of your device which can take a little getting used to, especially in the dark.




Even taking into account that you’re effectively getting 3 cases and an external battery, priced at $99.99 the Energi could not be described as a cheap solution. This is a premium product at a premium price.




Overall TYLT’s sliding power case is an elegant solution for those who need extra battery life. I’m one of those who would prefer a thicker phone if it means a larger battery, and if need be I’d be perfectly happy to carry my S4 inside this power case on a daily basis. However personally I find it difficult to kill the S4’s battery within a day, so day-to-day I’d probably choose another case due to the protection limitations. If you’re a heavy battery user then the Energi is highly recommended, but for the regular user I’d save it for situations such as travelling when you need the extra security that additional battery life affords.

Follow the link below to check out the Energi Sliding Power Case along with TYLT’s other cases for the S3, S4, S4 Mini and Moto X.



Associate Editor and part of the team of gadget reviewers at DroidHorizon. Also been known to dabble in software development to pay the bills.

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