I think you meant two AAA's. Measure each cell.
When unbalanced, one cell will rapidly become the weak link.
ALL batteries have memory or dual-layer capacitance, each with different series resistance, ESR.
The ESR is the part that gets hot, capacitance is like "Super-Ultracap" or is that an "ultra-Supercap" with a much higher density.
But the 2nd cap also has a higher ESR resistance and higher capacitance enough to restore the battery voltage from short term short circuits or heavy loads.
But it cannot deliver the same short circuit current and takes a longer time to recover while it can usually power a small LED as can a thin lithium coin cell which has a very high ESR so it naturally limits the current.
When a primary or secondary cell depletes most of its charge or becomes "dead" as they say, the chemistry raises the ESR significantly and also reduces the capacitance significantly.
This is why good Lithium smart chargers will start charging slowly until some 5 or 10% State of Charge (SOC) and then the impedance drops so a rise in current does not result in a measured significant rise in voltage and the ESR is thus that ratio \$\Delta V / \Delta I= ESR\$
So Alkaline cells do not have a built-in fuse but the depleted charge off the low ESR side builds up some oxide layer that raises its ESR so that it cannot accept as high a charge or deliver the same as when it was "fresh" or new. This is also the same effect on e-Caps at end of life unless damaged by over-current or reverse polarity charge.