REVIEW – The SolidSafe BMX portable battery is a Kickstarter project that features a normal looking charger device with secret sauce inside. The company claims a nail through the battery won’t affect its operation. Where’s my hammer? This ‘all or nothing’ project is open until September 15, 2025, but they’re already way over their funding goal. Come see what all the excitement is about.
⬇︎ Jump to summary (pros/cons)
Price: $63 Early bird pledge for the 5000 mAh unit. $75 for the 10000 mAh unit.
Where to buy: Kickstarter
What is it?
The SolidSafe BMX is a 5000 mAh or 10000 mAh battery pack containing a new, non-flammable energy storage and delivery chemistry.
What’s included?
- SolidSafe BMX power pack
- 5 ⅞” USB-C to USB-C cable lanyard
Tech specs
- USB-C input / output jack
- 5000 or 10000 mAh units will be available
- SolidSafe, non-flammable chemistry inside
- 1000 charge cycles estimated
- Multi-unit charger available
Design and features
SolidSafe sent two BMX batteries, the gold one and the black one. I gave the gold one to my wife to test. She likes the color. It matches her Fitbit.
The BMX battery comes with a short USB-C to USB-C cable which also serves as a lanyard. The cable connectors stay snapped into the lanyard’s plastic holder securely enough to use the lanyard confidently. I would not recommend snapping the charger to the outside of a backpack in case it got snagged and dropped, or pilfered.
The BMX is so thin that it is very comfortably pocketable.
About the safer power supply technology in the BMX chargers, the Kickstarter description says, “Traditional Lithium-ion batteries push charge through a flammable liquid. We’ve swapped almost all of that liquid for a solid oxide layer—about 97.5% solid, 2.5 % liquid, so there’s far less to leak or ignite. Paired with advanced cathode and anode materials, the pack stores roughly twice the energy of typical safer chemistries while staying cool even if punctured or crushed.”
They claim you can drive a nail through this battery and it’ll still work safely. They can do that to theirs, but it’s a comforting thought.
A question in the FAQ asks for an explanation of how SolidSafe batteries work, without using high-tech jargon.
“Picture a layered sandwich:
• Cathode (NMC sulfide) on one side stores energy.
• Anode (nanoporous silicon-carbide) on the other stores more energy.
• A solid oxide electrolyte sits between them and lets lithium ions shuttle back and forth during charge and discharge.
Because the electrolyte is nearly solid, even if the pack is punctured the heat can’t pool enough to ignite, yet the ions still move fast enough for stable 2 C charging and discharging.”
The company plans to implement Qi2, 15 W charging. The FAQ says “We’re building the power bank to meet the full Qi2 15 W magnetic charging spec. Our hardware already hits those electrical requirements, but the official Qi2 certification process is still underway. Until that paperwork is complete, you’ll see us describe the feature as 15 W magnetic wireless charging. Barring any last-minute hiccups in testing, the units that ship to backers will carry the Qi2 logo.”
Any phone that supports Qi or Qi2 and can hold a MagSafe-style ring will attach and charge. Otherwise USB-C to USB-C cable charging will work with the BMX.
The BMX charger supports ‘pass-through charging’. You can charge a device while the BMX is being charged.
The company reports that cycle-life tests show the pack holds 80% of its original capacity after about 1000 full charge cycles, which they equate to roughly three years of daily use.
So, if you back this project, when will you receive your SolidSafe BMX charger? “The SolidSafe Lineup is expected to ship in September. Depending on your location, you’ll get them sometime between September – Early October. Please note that this is an estimate, as you’re pre-ordering the product and production delays could arise.”
Setup
The power pack arrived displaying about 43% capacity, so I fully charged it and put it to use charging my primary phone.
Performance
I tested two 5000 mAh prototypes. I wondered about the large display area at the bottom of the unit, and found this: “The engineering samples only had a simple segmented display so we could validate charging logic. Final production units will ship with the full-color LCD that shows remaining capacity, live wattage in/out, and charging status.”
While the BMX has a power on/off button, it always came on when attached to a device we wanted to charge. It also powered itself off when unplugged from charging a device. But the power button is there if you prefer to turn the unit off manually. The power button is useful to check the power level of the BMX as turning it on activates its display.
During charging with the SolidSafe BMX battery, my phone shows a display that reads ‘Fast charging’. The AccuBattery app indicates the BMX charged my phone at over 3000 mA each time I used it.
My wife experienced a fair amount of heat coming from the BMX when she used it for MagSafe charging on her iPhone 14. I noted warming of the unit during corded charging as well. Neither of us would call it annoying heat, but there is some heat produced. The unit gets moderately warm but not hot, in our opinion. This charging behavior seems in line with some similar devices.
I saw no information on optimal charger wattage for charging the BMX, and it may not matter. As long as you’re using a modern charger with enough output power, they usually deliver the maximum power required by the device being charged. I used a 25 W phone charger and a 100 W charger to resupply the BMX.
With the 25 W phone charger it took 63 minutes to charge the BMX from 50% to 100% capacity.
With both chargers, it took 2 hours to charge the BMX from 0% to full.
Charging my Samsung phone’s 5000 mAh battery from 50% to 85% (which is where I usually start and stop phone charging) took the BMX about 30 minutes. The BMX dropped from full to 40-45% capacity during that phone charging cycle. This performance stayed the same over several cycles. Thanks to heat, resistance, and other factors, battery charging is not a 1-1 relationship between charger and device.
Final thoughts
You can find cheaper backup batteries than the SolidSafe BMX but may not find safer ones if the company is right about the chemistry inside these units. Act soon if you want the introductory prices on the BMX as it appears they will be shipping in October.
What I like about the SolidSafe BMX battery
- Thin, lightweight size
- The USB-C jack is input and output
- Simple operation
- Does fast phone charging
What needs to be improved?
- The battery is billed as, ‘for iPhone and more’. They may not want to overlook saying ‘Android’.
Price: 5000 mAh Early bird: $63. 10000 mAh Early bird $75. Other options, configurations and bundles are available.
Where to buy: Kickstarter
Source: The sample of this product was provided for free by SolidSafe. SolidSafe did not have a final say on the review and did not preview the review before it was published.
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$34.90 (as of September 1, 2025 02:09 GMT -04:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
