Why can’t you get all of that in one battery?
Capacity and current output are a trade-off. You can have lots of one, lots of the other, a reasonable mix of both but you can’t have your cake and eat it and this is why there are so many options. The limit is in chemistry technology. There’s only so much of each material you can fit in a battery and adding more of something that is good for capacity, takes away room for another which is better for current discharge ability. Until we find or invent new “ingredients” we can use instead of the current ones, this is where the limit lies. As above, different devices/products have different needs and the choice of battery for the job is decided by how much current it needs, and how long it needs to last it for before charging. At the time of writing, 30amps is about the very best that can be achieved from a single 18650 battery. The LG HB2 and LG HB6 in our shop can provide this level of current but with only 1500mAh capacity. Likewise, the LG MJ1 has a capacity of 3500mAh, the highest commonly available capacity on the market right now but because of this, is limited to only 10A constant discharge.
There are lots of batteries being advertised on eBay, Amazon, Alibaba etc with wild figures like “50A constant discharge” and “9000mAh capacity”. These are all LIES. Do not fall for them. It is impossible to have more than 3600mAh in capacity or 30A in constant discharge. At the time of writing, these are the limits of current chemistry technology available to the market. That’s not to say new chemistries aren’t being developed (Lithium Titanate is being developed by Toshiba in their SCiB range, Lithium Sulphur/Li-S by other, privately owned and independent technology companies like Oxis Energy), just that they are currently unavailable to us or at least not in 18650 form.