I believe they can make a 60W 100Wh. The challenge will be the ergonomics of the shape and the shape's impact on weight. They once made a slab shaped product but they canned it.
The problem to solve:
- You can drive about 2A 3.7V = 7.4W per 3400mAh or 12Wh 18650 cell, so you can drive out of 8 cells 96Wh 60W. So yes, 60W output of a 26800mAh is viable from a chemical energy perspective.
- The issue is driving 8 cells together in a power bank is going to cause each cell, particularly the 4 in the middle of a 2x4 construction, to become hotter by their proximity to each other within the one powerbank. Heat leads to expansion and you increase chance of failure.
- So ironically, the bigger the total amount of energy, due to heat, the less Wattage per unit of energy. So say a 20Ah could be made to be driven to 45W but a 26800mAh to 60W is harder.
- You can reduce the thermal problem by not using 18650 cells but say Lithium Polymer, and make a thin slab like product, but then you come up against that a 18650 cylinder is stronger than a Lithium Poly rectangle so to compensate and make a strong product you must thicken up the outer packaging, then you end up with the product being heavier, i.e. a 26.8Ah is more weight than the 34% in weight than it is capacity.
This problem of in effect exponential weight with Wattage you see the Powerhouse. It is 434Wh, vs say a 26800mAh 96Wh, so is 4.5x the energy stored but is 8x the weight.
So then you hit the what is the point of a "portable charger".
I would suggest that you trade off the fact you have portable energy with being less obtuse about its use, to not so much ask for Wattage but, because it is portable, you have it with all the time anyway, you plug it in proactively, early, and accept a slower recharge. I'd prefer to lug lighter portable charger, and not be such as a fool and want a heavier one so I can carry it unplugged for longer.
Personally I would prefer a lighter smaller slower portable charger.
There is an analogy in astrophysics, smaller brown dwarf suns shine potentially for trillions of years but larger blue giants burn in millions of years.