A sodium-ion power bank swaps the lithium in a normal power bank for sodium. The one consumer model we found, the Elecom DE-C55L-9000 from Japan, claims about 5,000 charge cycles and use down to -35°C. It’s also heavier and pricier than a lithium pack, and we found no confirmed U.S. listing. For most buyers today, a regular lithium power bank is still the practical choice.
The technology is real, and Elecom says it is the first company to sell one. But nearly everything below is the maker’s own claim. We haven’t held one or tested one, and as far as we found, no independent review of this power bank has been published.
What Is a Sodium-Ion Power Bank?
Inside every power bank are battery cells. Most use lithium-ion. A sodium-ion power bank uses cells that move sodium ions instead. Sodium is far more common than lithium, which is why makers talk about lower cost and less mining in the long run. Notebookcheck’s coverage says sodium is more abundant and easier to produce, and Elecom says sodium avoids the cobalt and lithium mining concerns.
The catch is energy density. Sodium-ion cells pack less energy into the same weight, so a sodium-ion power bank has to be bigger or heavier for the same runtime.
The One Sodium-Ion Power Bank We Could Find
Elecom announced it in March 2025 and called it the world’s first. Here is what its listing and press coverage say, next to a typical lithium power bank:
| Elecom DE-C55L-9000 (sodium-ion) | Typical 10,000 mAh lithium pack | |
|---|---|---|
| Rated capacity | 9,000 mAh | 10,000 mAh |
| Weight | 350 g | About 212 to 244 g (Anker models, per New Atlas) |
| Price | 9,980 yen, about $67 in Japan | About $16 to $24 (per New Atlas) |
| Max USB-C output | 45 W | Varies |
| Cycle life (maker’s claim) | 5,000 | 500 to 1,000 (per New Atlas) |
| Discharge temperature | -35°C to 50°C | Varies by model |
| Charging temperature | 0°C to 40°C | Varies by model |
Screenshot this table, because it shows the trade in one glance: much longer claimed life, but more weight and a much higher price.
Why 9,000 mAh Isn’t Smaller Than 10,000 mAh
This one trips people up. The capacity numbers on a power bank are measured at the cell’s voltage, and sodium-ion cells run at a lower voltage than lithium. Elecom’s spec lists the cells as 3.0V and 3,000 mAh each, three of them. Multiplying 3.0V by 9 Ah gives about 27 Wh. A typical lithium power bank rated at 10,000 mAh at 3.7V works out to about 37 Wh. That’s our own arithmetic from the listed ratings, not an Elecom figure. The takeaway is that comparing mAh across the two chemistries understates the gap, so compare watt-hours when you can. Our power bank decision guide explains the Wh math.
The Cold-Weather Claim: Read the Fine Print
Elecom says the power bank can discharge from -35°C to 50°C. That’s the number making headlines, and if true it would beat what lithium packs generally offer. But the same spec lists a charging range of 0°C to 40°C, and Notebookcheck’s coverage leaves the charging limit out. Elecom also says output may drop or stop depending on conditions.
So the real picture is: the claimed benefit is for using the power bank in the cold, not for charging it in the cold. That’s the same rule lithium packs follow. Battery University’s guide to charging at high and low temperatures says lithium-ion shouldn’t be charged below freezing. If you want a practical cold-weather routine today, our guide to using a power bank in cold weather covers what works with the lithium packs you can buy now.
A related bigger product exists: Techlicious covered Bluetti’s Pioneer Na, a 900 Wh sodium-ion portable power station that Bluetti says charges down to -15°C and discharges down to -25°C. It weighs 35 lbs, about 20 to 25 percent more than comparable lithium iron phosphate power stations, per Techlicious. That’s a camping power station, not a pocket power bank, but it shows the same trade-off at larger scale.
Safety: What’s Claimed and What Isn’t
Elecom says sodium-ion cells are “less likely to cause thermal runaway,” and lists PSE compliance (Japan’s electrical safety mark), temperature monitoring, and five protection functions. Those are the maker’s statements. We found no independent safety testing of this power bank. And “less likely” isn’t “can’t.” If you’re worried about any power bank you own, our guide to checking whether your power bank is recalled works for every chemistry.
Can You Buy One in the U.S.?
We found no confirmed U.S. listing. Notebookcheck and New Atlas both describe sales through Elecom’s own Japanese online shop, and the coverage we read didn’t mention Amazon or other regions. We can’t see current stock or shipping from here, so check Elecom’s site yourself. If you import one, you’d be relying on a Japan-market product with a one-year warranty that may not cover you abroad. That last point is our caution, not Elecom’s statement.
Is a Sodium-Ion Power Bank Worth Waiting For?
It depends on what you want from a power bank.
| If you want… | Our take |
|---|---|
| The lowest price and lightest weight | Buy lithium. Sodium-ion loses on both for now |
| A pack that lasts for years of daily use | Sodium-ion’s claimed 5,000 cycles are interesting, but unproven. A cheap lithium pack replaced every few years may cost less |
| Reliable use in freezing weather | Still keep it warm and charge it indoors. The charging limit stays at 0°C |
| To follow new tech | Watch for independent reviews and a U.S. release before paying import prices |
The cost math is worth doing. At about $67 versus $16 to $24, the sodium-ion pack would need to last roughly three to four lithium packs before it breaks even. That’s our simple arithmetic, and it only holds if the 5,000-cycle claim survives real use.
What to Buy Today
A normal lithium power bank from a brand with a published recall page is still the safer, cheaper bet. Look at the rated Wh, the USB-C output, and the maker’s recall history. If you’re shopping for a specific use, we’ve covered power banks for a heated vest and for a router.
👉 Browse 10,000mAh USB-C Power Banks | Browse 20,000mAh Power Banks
Frequently Asked Questions
What is a sodium-ion power bank? It’s a portable charger that uses sodium-ion battery cells instead of lithium-ion. Sodium is more abundant, but the cells hold less energy for their weight, so the pack is heavier for the same runtime.
Can you buy a sodium-ion power bank? Elecom sells one in Japan, the DE-C55L-9000, through its own online shop. We found no confirmed U.S. listing, so check availability before you plan around it.
Does a sodium-ion power bank work in the cold? Elecom says it discharges from -35°C to 50°C but charges only from 0°C to 40°C. That’s a maker’s claim we haven’t tested, and it means you still shouldn’t charge it below freezing.
Are sodium-ion power banks safer than lithium? Elecom says its cells are less likely to cause thermal runaway. We found no independent safety testing, so treat it as a claim, not a guarantee.
How long does a sodium-ion power bank last? Elecom rates it at 5,000 charge cycles, versus 500 to 1,000 that New Atlas gives for lithium-ion. That’s a rating, not a measured result.
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Sources: Notebookcheck — Elecom launches world’s first sodium-ion mobile power bank | New Atlas — World’s first long-life sodium-ion power bank launched | PCWorld — Elecom Na-ion power bank has 10x more charging cycles | Offgrid Technology — New sodium-ion power bank from Elecom | Techlicious — Bluetti Pioneer Na sodium-ion power station | Battery University — BU-410 Charging at High and Low Temperatures