@SergeiF
As you've noted, LiPo uses a different chemistry inside (LiFePo4 etc,).
Phil
Phil, a bit of correction there: LiPo battery now (not originally) specifies polymer packaging (not chemistry). There could be LiPo Li-ion lithium cobalt oxide , or LiPo LiFePO4, or LiPo lithium manganese oxide or lithium nickel manganese cobalt oxide chemistry variants (very rare). Most of commercial LiPo batteries (rectangular pouches) are of cobalt type, second most common type is LiFePO4.
LiPo never means it is only LiFePO4.
Originally there was development of organic based electrolyte, thus "polymer" in the name, but due to marketing, now any battery in plastic (polymer) case (without metal rigid can/cell) is called LiPo.
In anyway, regular high density Li-Ion cobalt based chemistry is the explosive type. This type of LiPo is more dangerous than the metal can (or other Li-ion chemistries).
The reason why Cobalt based chemistry is so prevalent is simply due to higher (>30%) energy density.
In my opinion LiFePO4 is more superior technology due to simple fact that it can take more abuse.
While going back to miliamp hour ratings vs watt hours, it is a bit of misleading to simply calculate the Whr rating by multiplying amp hour by nominal voltage. One must look at the discharge graph and the area under it to determine actual Whr rating (or experimentally).
For example:
A battery that starts off with 1.5V with capacity of 1Ah, which drops off to 1.2V at 85% charge will have less watt hour than the battery that start with 1.5V with same 1Ah capacity which drops off to 1.2V at 50% capacity. Even if both have nominal 1.5V voltage and 1Ah capacity.
Li-ion (Cobalt) have nominal voltage of 3.6-3.7V but are starting off at ~4.2V, and safe low cut-off is at around 3.2V with relatively steep drop off (with 90% capacity used).
Li-ion (Iron) have nominal voltage of 3.2V, but are starting off at ~3.6V, and can safely be discharged as low as 2.7-2.5V with very flat discharge curve (more area under the curve).
Here is the graph I blatantly lifted off via the google image search that will explain why you would have different watt hour figure that the simple multiplication would show:
