Tylt’s Energi Sliding Power Case ($100) is the first battery case we’ve seen for iPhone 6, though we have seen a previous version of Energi before, for iPhone 5. Energi comes with a simple standalone case, which can then be inserted in a larger 3200 mAh battery sleeve with a built-in Lightning connector for charging on the go — the two pieces work together as a bigger, thicker case. While the design here is similar to the previous Energi case, the battery now has a higher capacity, and the inner case offers more protection than before. The sleep/wake buttons and volume controls are now covered, as are the top and bottom of the phone. A micro-USB cable is included for charging the battery.
As in the past, we really like the design of Energi.
It’s nice that Tylt has taken an extra step to improve the coverage of the simple case — you’ll feel better using the case without the shell now, considering the added button coverage. The case slides into the shell nicely, where it docks on a Lightning plug for charging. While the iPhone’s side buttons remain a bit recessed while the case is in the shell, we didn’t find that to be much of a problem — though the ringer switch is a bit of a pain to get to while the phone is charging.
The shell itself adds some thickness, but it’s not overly bulky. Two ports in the front of the shell reroute audio from the bottom of the iPhone, and a headphone port and micro-USB port are on the bottom of the shell. Tylt does not include a headphone extender this time around due to Apple changing its specifications for headphone jacks — Tylt is reworking their headphone adapters to meet the requirements, and users can contact the company to receive an adapter.
Four LEDs on the back show users how much battery life is left, and those LEDs rest on a clicky power button that turns the battery on or off.
During the testing of Energi, however, we encountered something strange. The battery recharged an iPhone 6 very quickly, though not fully — it took 2:09 to get an iPhone 6 to 99 percent. Strangely, 99 percent is where the battery charge remained before shutting off, even though there was still some charge left in Energi. Tylt notes that Energi is designed to stop charging at 100 percent to save power, but for us, it stopped just short. After draining the iPhone’s battery again, we were able to get another 21 percent charge out of the battery, for a total charge of 120 percent.