TechnologyTell Review: Juno Power Nova Blox battery

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After having had a few metal-body external battery packs to test out, I’m really starting to dig them. Sure, there are some plastic batteries, be it hard or soft, that are quite fetching. But there’s just something about the look and feel of metal. Like the device is more expensive than it really is, especially when it’s smaller and cuter. Like the Nova Blox from Juno Power.


I’m pretty sure I’ve said it a number of times before, but I’m a sucker when it comes to brushed metal exteriors. And the Juno Power Nova Blox battery is no exception. There are only three pieces of plastic you can touch: the power button, and the top and bottom where the USB connectors are. The plastic on the ends are secured with teeny screws. The rest of the Nova Blox is pure, satiny, machined aluminum.

Juno Power Nova Blox battery box

Simple box, simple battery.

It’s a little odd to find the input and output USB ports on opposite sides. Typically the business end of an external battery pack is all together. Maybe the design team felt this style to be a little more intuitive for anyone wanted to employ the Nova Blox’s passthrough charging. It’s possible. When passthrough charging, very little (if any) energy gets stored in the Nova Blox until the connected device fills up first.

This is about as standard as you get for an external battery pack. The single power button engages charging and toggles the ‘flashlight’ on and off (press-hold). There is no auto-detect output for the Nova Blox, but it does turn itself off after 10 or so seconds of not sending any power out.

Four blue LEDs shine through pinholes on the front of the battery – front has the logo and rear shows the input/output stats. It’s the basic means of estimating the amount of battery power left, with each LED indicating a 25 percent threshold.

It’s a very, very rough estimate for most battery packs, the Nova Blox included. Thankfully, the LEDs glow while the battery is charging out, making it easy to tell when charging is done with just a quick glance.

Juno Power Nova Blox battery port

Single port, not too bulky of a body.

The built-in flashlight is basic, similar to the output you might get from a standard keychain flashlight. Normally I find this feature a waste when it comes to battery packs, since the majority of them are so physically big. But the compact, portable size of the Juno Power Nova Blox makes it work. It’s small enough to hold in the hand without feeling ridiculous. The light output versus overall size feels appropriate.

Although the Nova Blox can charge out up to 2.1A, you won’t get that benefit the with included cable. The cable is your basic 5V/1A kind. Those who want to charge either the Nova Blox and/or other devices faster are going to have to use one of their own, better cables. It’s kind of a bummer when the included cable can’t keep up with the device, but this is a pretty common practice.

Battery Performance

Now I’m not entirely sure if I received a lemon or not, but the actual input and output rates haven’t gone as high as I’ve been expecting. I use a PLX Devices Legion Meter as my measurement tool. The Juno Power Nova Blox listed input is 1.5A, however the functional rate rarely peaks over 480mA. That’s about as good as trying to charge from a laptop’s USB port. I even tried the cable that came with the battery, as well as my own fast-charge cables, and it didn’t make a difference.

Juno Power Nova Blox battery light


The USB output rate is supposed to reach up to 2.1A. But the actual rate also falls short of what I would expect to see from devices I’m charging. Instead of an expected 1.5A (roughly) to my Galaxy Note 4 battery, I’m getting between 800mA and 1.03A. And the rate is constantly changing – more than I’m used to seeing from a battery pack.

I don’t think that it’s too big a deal. The 4000mAh Nova Blox battery capacity is small enough where charging it fully doesn’t take too long. Either way, it knows to shut off automatically when the connected device is full, and the heat generated is kept to a nice minimum.

Note: Most external battery packs I’ve ever purchased and used came only partially charged, so I’ve always made it a habit to fully charge them before use. I tend to fully charge and discharge a new battery a few times, just so I can level out the charge states of the individual cells. It helps to maximize the battery’s manufacturer-listed potential.

Juno Power Nova Blox battery palm 2

Definitely compact and great-looking

The standard efficiency rating of external battery packs currently on the market is 70 percent. This means that 30 percent of the battery’s listed capacity is consumed while charging up devices. So, for example, a basic 1000mAh battery would effectively deliver 700mAh of energy.

Right out of the box, the Juno Power Nova Blox was able to deliver a total of 82 percent charge, or 2640mAh of usable energy, to my Samsung Galaxy Note 4 battery (3220mAh). That’s equivalent to 66.0 percent efficiency, which is ok. I’ve seen much worse. However, additional charge cycles brought up the values to a peak of 73.2 percent and an average value of 71.7 percent. That average is equivalent to 2868mAh of usable energy.

So what can you do with 2868mAh of battery energy? That’s good for 0.89 full charges to a Samsung Galaxy Note 4 (3220mAh), or 1.5 full charges to an Apple iPhone 6 (1810mAh), or 0.63 full charges to a 7″ Kindle Fire HDX (4500mAh). Not too bad a performance for such a compact thing.


If you’re looking for a basic external battery pack that is compact to carry, even in pants pockets, you can’t go wrong with the Juno Power Nova Blox. Although it’s simple with its single USB output, the 4000mAh capacity and slightly-above-average efficiency should be enough for most users.

And if we assume that my review unit wasn’t performing at its best (a lemon), then the faster charge rates of the Nova Blox definitely push it ahead of some peers. A lot of new mobile devices are coming out with faster charge rates (e.g. smartphones, speakers, etc), and it never hurts to take advantage of having a shortened charging time.

Besides, it’s metal. That trumps plastic any day, all day, in my book. So if you want a highly-portable external battery that you can coordinate with your other gear, the Nova Blox comes in gray, gold, and silver. Go check it out!


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