When an battery case adds only just over half of the phone's capacity while nearly doubling the thickness of the package, it's time to rethink the utility of the solution.
Over the years, I have purchased a few Mophie Juice Pack battery cases in airports around the country as I deployed to remote locations to get work done. For most phones, battery life has improved the last couple of years, but I think Samsung is a bit gun shy after its Note 7 fiasco, and we are not seeing stellar battery life from its latest smartphone.
While I think the Samsung Galaxy S9 Plus (see my full review) is one of the best Android phones available today, after using it for more than a month, it is clear to me the battery is just barely acceptable for a flagship. When I compare the Huawei P20 Pro (see our full review) that gets me through almost two full days of moderate to heavy use, running out of battery on the S9 Plus mid-evening is a terrible experience that actually adds a bit of stress to my day as I watch the battery drain without a power source in sight.
Mophie's new S9 Plus Juice Pack can help make sure you get through that one full day, but it can't do much more than that. The Galaxy S9 Plus has an integrated 3,500mAh battery that may get some through a full day, but not if you are actively using it and also taking photos and video. The Mophie S9 Plus Juice Pack only adds another 2,070mAh, so you are likely not going to get through that second full day with this $99.95 accessory.
The retail package includes the two pieces of the Mophie Juice Pack, a USB-C cable, and a pass-through headset adapter. The USB-C port on the case is designed so that just about any current cable you have should work, but the headphone jack is recessed quite a bit at the bottom of the case, so it is unlikely your default wired headphones will work. Unlike Juice Packs of the past, there is no dongle for the 3.5mm headset jack, so you may have to resort to only using Bluetooth wireless headphones while using the Juice Pack.
While wireless charging may not be that important to the masses, it's a convenience I have come to embrace in my life with wireless charging stations on my nightstand, on my home office desk, and at my engineering office desk. I love that I can just drop a Samsung Galaxy phone down on a charger to top it off without worrying about connecting a cable. Mophie integrated wireless charging into the Juice Pack, so even when your S9 Plus is mounted inside, you can set the Mophie package down and charge it up without wires. You can also charge up the Mophie Juice Pack wirelessly without the S9 Plus being positioned inside the case. The case supports the Qi wireless technology that is the standard for most all smartphones now.
When plugged in or set down on a wireless charger, the Mophie Juice Pack will top off your S9 Plus first and then charge up the case so that your phone is prioritized for use without the case. There is a button and four bright white LED indicator lights on the back to provide you with the battery pack status. Press and hold the status button for two seconds to begin charging your phone. There are buttons on the side for volume and power and an ample camera and flash opening so that the quality of your photos is not impacted.
The Mophie Juice Pack is a two-piece solution. Slide your S9 Plus down onto the embedded USB-C fitting at the bottom of the case and then snap on the top frame piece to secure your S9 Plus in place. The Mophie Juice Pack is designed to provide some protection from drops, too, which is important when you have a phone with a glass back. The case curves down along the edges so you still get full edge functionality with the appealing design aspects present as well.
The opening for the dual cameras, flash, sensors, and fingerprint scanner is very large and actually pretty deep. You may have to adjust how you touch the fingerprint scanner to accurately and quickly unlock your phone.
The Mophie Juice Pack adds bulk to the S9 Plus device and weighs in at 96.4g. It is curved on the back to make holding it more comfortable, but it is still a thick package in your hand. I would be willing to accept this if it had at least a 3,500mAh battery inside, but it is almost just half of that capacity.
The case is also covered in matte, soft touch black material so it makes it easy to grip and hold onto your S9 Plus. Unlike some people who always carry their phones in a Mophie, I would only use it during time when I plan to be away from a charger because the added bulk just isn't worth it to me.
While the Galaxy S9 Plus is water resistant, the Mophie Juice Pack is not so be careful using this case solution in the rain or other wet environments.
I would prefer to see a Juice Pack with a battery capacity that matches that of the phone, so you could trust you will have power for a full long day out in the field. There is quite a bit of bulk added by the Juice Pack, and at just 59 percent of the capacity of the integrated battery, I have a tough time justifying a $100 accessory like this.
If you really need to provide a solution for additional battery life on the Galaxy S9 Plus, then look to spend the same $100 on the 12,000 mAh Powerstation Plus XL or a bit more on the 19,500 mAh Powerstation USB-C XXL. I carry these types of batteries when I travel and know I will not have access to a power source.
The Charge Force cases are also a better solution than the Juice Pack since you get a nice slim leather case and can then simply slap on a higher capacity battery for mobile usage. You can get a 3,000mAh Powerstation mini battery for $49.95. Unfortunately, there is not yet a Charge Force case for the Galaxy S9 Plus.