A 10,000mAh power bank does not always mean 38.5Wh output energy.

One thing I often discuss with customers:

“Why is the actual output energy lower than the battery energy?”

For example, a battery cell may be:

• 3.85V
• 10,000mAh
• 38.5Wh

But the energy delivered from the power bank output is not exactly 38.5Wh.

Why?

Because there are losses in the whole system:

• Power conversion efficiency
• PCB consumption
• Protection circuit loss
• Cable and connector loss

The battery cell is only one part of the product.

When evaluating a power solution, the more important question is not only:

“How many mAh does the battery have?”

but also:

“How much usable energy can the complete system deliver?”

A good battery solution is always about the balance between the cell, electronics and real application.