So I have loved this battery. I got it as a giveaway at a business event. It would give me 30-40 percent extra charge on my iPhone 14 Pro. Which was great. Just enough to get me through days I had used the phone a lot. But now about 9 months after I got it, the battery has failed and the device has started to swell. I would be hesitant to buy another one or buy it for someone else if I am going to be replacing it every 6-12 months.

This is my fifth Dark Energy product. That includes the model I bought when the company was a Kickstarter campaign. Worth noting, that battery still works to a degree (charge a phone to full once, at least), but how old is it? I doubt other batteries last that long (lifespan) or suffer that much abuse. That's why I purchased four more.

However, the Nano is a disappointment.

First, the good. The size, weight, fit & finish are great. Second, the fact that it includes cordless charging can be a lifesaver, especialy if you don't have a cable.

However, the whole "top off the phone" idea might have made sense in the product planning meetings, but here is why it's substandard in the field. A) A phone with an older battery would be the target market, but on my wife's iPhone 14, she only gets a max of 20% refill. On my newer model I get about 50%. So the more you need a Nano, the less likely it is to meet your needs. B) at half-the price of the Poseidon, it only has 20 to 25% of the charging capability. I understand build quality and size constraints are at play here, but had I tested it as soon as I got it, I would have been looking into a return. C) They're (slightly) better now, but the original adverts and pages for the Nano were not exactly leading with 'this is a top-off band aid for total emergencies.' I'm sorry, but I can get a ratchet 'stick-some-AAs-in-this-chinesium-case-and-keep-your-phone-alive' products for a fraction of the cost of Nano. Bottom Line: if you know you need something for this specific task, want it small, has mag-safe charging, and want to feel good knowing it's well built, then Nano is for you. Otherwise buy a Poseidon. Full stop.

Gambled on the Nano for backpacking power along with the solar charger for simple watch and phone charging, and I lost the bet! Barely charges my phone about 15 to 20 percent before depleting. Lite and tough design, but hugely disappointed. Not worth the investment. Recommend sticking with proven quality brands you’ve come to trust.

It is not worth the money as I can’t even get a full charge out of it. It will only charge my phone to about 50% at best. But I guess that’s better than it going dead.

The Nano would only charge about 30% of my iPhone 17 on a single charge. I would have expected it to charge my phone more. It felt very large for such a small 3,000 MAH battery. At a minimal this charger is too small to be effective at anything I own. Wish I would have know about the 40% thermal loss as this makes such a small charger ineffective.