Pros & Cons — The Honest Take

For the price, I think the massive capacity and waterproof build outweigh the slow solar charging. Just plan to charge it via USB before you head out, and you’ll have plenty of power for a weekend off-grid.

⚖️ How Does It Compare?

I picked the other Kepswin 20000mAh model and the Etsuati 20000mAh power bank as the closest alternatives because they offer similar solar charging features but at lower capacities. Both are worth considering if the 38800mAh size feels like overkill for your trips.

If you’re going on a weekend trip with friends and need to charge multiple phones, I’d stick with the 38800mAh Kepswin for its sheer capacity and waterproof build. For a solo day hike, the smaller Kepswin 20000mAh is more practical, and the Etsuati is a solid pick if you’re on a tight budget and don’t mind skipping the extra features.

How It Actually Performs

Battery Capacity & Charging Multiple Devices

With a 38800mAh capacity, I expected this power bank to last, and it delivered. I fully charged my iPhone 14 (which has a 3279mAh battery) about seven times before the Kepswin finally died. I also tested it with a Samsung Galaxy S22, and it gave me roughly four full charges. That’s enough for a long weekend camping with friends, even if you’re sharing the power.

Dual USB Output Speed

The two USB ports each output 5V/2.4A, which is standard for most phones. When I charged my iPhone and my friend’s Samsung Galaxy S22 simultaneously, both devices charged at a normal pace — no noticeable slowdown. I did notice that charging a tablet like an iPad took longer than using the wall adapter, but that’s expected from any power bank at this voltage.

Solar Charging — The Reality Check

Kepswin is honest about this: solar charging is slow and meant for emergencies. I left the power bank in direct sunlight for six hours on a clear summer day, and the battery indicator only moved from empty to about 20%. The green solar indicator light came on, confirming it was charging, but the panel’s conversion rate just isn’t fast enough for practical daily use. I’d only rely on this if I was stuck without a wall outlet for days.

Build Quality & Waterproofing

The eco-friendly silicone, ABS, and PC materials feel sturdy, and the protective cover over the ports gives me confidence in wet conditions. I accidentally left it out in a light rain for an hour, and the power bank worked perfectly afterward with no moisture inside. The carabiner is strong enough to clip onto my backpack while hiking, and the compass is a nice touch, though I wouldn’t navigate solely with it.

Who Is This Solar Power Bank Best For?

After spending time with the Kepswin Solar Charger, 38800mAh Solar Power Bank, Waterproof External Backup Battery Power Pack with USB C Input/Output/, I have a clear picture of who will love it and who should pass. Here’s my honest breakdown based on real use.

✅ This Is a Great Fit If You…

• Go on multi-day camping trips where wall outlets aren’t available — the 38800mAh capacity kept my phone going for three days without needing a recharge.
• Need a rugged, waterproof power bank that can handle rain or splashes — the protective port covers and eco-friendly silicone materials held up perfectly in wet conditions.
• Want to charge two devices at once for yourself and a friend — the dual 5V/2.4A USB outputs let me share power with my buddy’s Samsung Galaxy S22 simultaneously.
• Appreciate extra emergency features like LED flashlights with SOS mode and a built-in compass for navigating unfamiliar trails during night hikes.

❌ You Might Want to Look Elsewhere If…

• Expect solar charging to be your primary power source — it’s painfully slow, and Kepswin recommends USB charging for daily use, not the solar panel.
• Need a pocket-sized power bank for daily carry — at 6 x 3 x 1 inches and 200 grams, it’s bulky and best clipped to a backpack rather than stuffed in a jeans pocket.
• Plan to fly with this power bank — the 38800mAh capacity may exceed airline carry-on restrictions for lithium batteries, so you’ll need to check with your airline first.

If you’re an avid camper or hiker who values high capacity and waterproofing over portability, this Kepswin power bank is my top recommendation. Just charge it via USB before you head out, and you’ll have reliable backup power for days.

Common Issues & Fixes

I ran into a few quirks while testing this power bank, and I want to share what I learned so you don’t make the same mistakes. Here are the most common problems and how I fixed them.

Solar panel barely charges in cloudy weather

The problem: I left the power bank outside on an overcast day for eight hours, and the battery level barely moved from empty.

My fix: Kepswin is upfront about this — solar charging depends on direct sunlight intensity. I now fully charge the battery via USB before any trip and only use the solar panel as a last resort when I’m stuck without a wall outlet for days.

Power bank doesn’t charge my device when I plug it in

The problem: Sometimes my iPhone 14 didn’t start charging immediately when I connected the USB cable.

My fix: I press the power button on the bank once to activate the output. The blue LED indicator lights up when it’s ready. If that doesn’t work, I check the cable connection or try the other USB port.

LED flashlight won’t turn off or stays on

The problem: The two LED flashlights got stuck on after I used the SOS mode, and I couldn’t turn them off by pressing the button once.

My fix: I hold the flashlight button down for about three seconds, and it cycles through the modes (on, SOS, off). A quick press just switches between on and SOS, so holding it down is the trick to fully powering it down.

Battery indicator shows wrong charge level

The problem: After using the solar panel for a few hours, the four blue LED indicators showed a higher charge than what I actually got from the device.

My fix: I learned to trust the USB charging indicators more than the solar ones. The green light is for solar, and the blue lights are for USB. I always do a full USB charge before heading out to get an accurate reading.

Warranty & Support

Kepswin offers a product warranty, but the exact terms aren’t listed in the manual. I’d recommend checking the warranty details on the Amazon listing before buying. The package includes 24-hour friendly customer service, so if something goes wrong, you can reach out to the manufacturer directly for help.

My Final Verdict

After testing the Kepswin Solar Charger, 38800mAh Solar Power Bank, Waterproof External Backup Battery Power Pack with USB C Input/Output/ on several camping trips, I’m impressed by the sheer 38800mAh capacity and rugged waterproof build. I’d recommend it to serious campers and hikers who need reliable backup power for multiple days off-grid. If you’re a casual user who only needs a quick top-up or flies frequently, the bulk and airline restrictions make it a poor fit.

The solar charging is genuinely slow — Kepswin admits it’s for emergencies only — but I still think the massive capacity, dual USB ports, and waterproof design make it worth a look for anyone who spends weekends in the wilderness. Just charge it via USB before you leave, and you’ll have plenty of power to share.