Only the Dizaul has worked well for me. I charged it from home, then put it on my pack to solar recharge between uses. My phone Samsung Galaxy S7 has a 3000mah battery So only one charge came from home

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Solar Charger,Dizaul 5000mAh Portable Solar Power Bank Waterproof/Shockproof/Dustproof Dual USB Battery Bank for cell phone,iPhone,Samsung,Android phones,Windows phones,GoPro Camera,GPS and More