Was the battery empty before you charged it?, On my AAA E01R my usb battery meter mah reading was very close to the discharge capacity on my Maha C9000, So your 725ma on an empty AA 2000mah is not even 50% charged.
I discharge the nimh to 0.9v in my maha c9000 then charged the battery in the Jetbeam till the red led turns off, Then i take out the battery and measure the voltage, I get 1.37 or 1.38v then i discharge the battery in my Maha C9000 at 100ma to see the actual capacity the Jetbeam put into the empty battery.
I have done 6 charge discharge cycles and 5 were only 50% capacity, 1 was 75% capacity of the battery capacity on my E01R AAA
So you need to do this on your AA E10R to check out the nimh charging.
The battery was empty before it began to fill.
The method is not precise, the ideal is to measure in discharge. But this gives us a rough idea. Normally, I put in my Fujitsu 1900 mA around 2200mA with this method. And now I only get 725mA, around 1/3 …
Aw IMR unprotected is really very short battery, but the E10R runs fine with it (of course I will not charge this IMR unprotected battery inside the light)