NiMH's don't power camera even with sufficient voltage

[btgc]

Set of four regular Sanyo 2700 NiMh AA's couldn't power neither digital compact or IstD. Checked voltage - 1.32V. Put them into several flashes (where I mostly used them before) and they charged. Recharged cells and with 1.41V they again couldn't power up camera. They have several years behind them, but in terms of recharge cycles...probably 20 at max, as I haven't used them daily (which could be cause of issue, just like with cars sitting mostly in garage).

Can someone point out to basic electrical nuance I'm observing here? Yet do I face need for new set of batteries or for smarter charger with discharge option (though I always have charged them when voltage drops close to 1.2V).

Note my other batteries - Uniross Hybrio 2100 (probably rebrands of Eneloops as there are not many factories on planet making LSD cells, I read) at 1.3V power up AA-based cameras just fine so I figure issue is with particular set of Sanyo 2700's.

 

[Spanik]

Internal resistance has become too large. If the internal resistance is high (relative speaking) then the voltage drops when it has to deliver current. What you see is the camera powering up and drawing a large current. With those batteries the voltage drops too much and the camera doesn't even come to life.

If you measure with a voltmeter, this has a very high resistance so you won't see a voltage drop. Try measuring the voltage without load and with a 3.3 Ohm resistor over a cell.

For a flash this isn't a problem as they are designed to work from disposable batteries and their internal resistance becomes high when they discharge. So flashes are designed to be able to work from lower voltages so they can pull the last out of alkalines.