What’s Inside pSolPack? Real-World Usable Capacity & Architecture Test

When shopping for off-grid solar storage, there is often a massive gap between nameplate capacity and real-world usable output. Spec sheets might show impressive battery ratings, but step-up conversion losses, heat dissipation, and cable resistance tell the true story once deployed in the field.

We put the pSolPack 5W Solar + 8000mAh Battery Pack through a calibrated bench test to measure its actual energy transfer efficiency. Watch the complete breakdown and efficiency test below:

YouTube Video

The Power Architecture

The pSolPack is housed in an IP-65 weatherproof enclosure, engineered specifically to provide continuous 24/7 power for security cameras, trail cams, and outdoor IoT gear.

Inside, the system relies on a 1S4P configuration of four 18650 rechargeable lithium-ion cells:

• Cell Rating: 2000mAh at 3.7V (7.4Wh per cell)

• Total Storage: 8000mAh at 3.7V

• Nameplate Capacity: 29.6 Watt-hours (Wh)

The Real-World Efficiency Test

To measure true usable capacity, we fully charged the pSolPack in full sunlight and connected a calibrated USB inline power meter. We placed a continuous dual-device load (a phone and a Chromebook) on the system to draw down the stored energy.

The Results:

• Total Usable Energy Transferred: 24.47 Wh over 7 hours

• Measured Output: Stable 3–4W delivery via standard 5V USB

• Overall Energy Efficiency: 82.7%

Achieving an 82.7% real-world efficiency rating is a strong result for a compact solar-battery system. This accounts for the internal DC-DC boost converter stepping nominal 3.7V battery power up to standard 5V USB output, as well as the minor voltage drop along the included 10-foot power cable.

Get Yours & Customization Options

• 🛒 Order on Amazon: Grab the pSolPack $25 Launch Special on Amazon (includes standard wall and ground mounting hardware).

• 🖨️ Open-Source 3D Mounts: Want to mount your pSolPack directly onto a glass window or RV side panel? Download our free, open-source 3D-printable suction mount STL files on our Open Source Projects Page.