Hello,
I want to test some NiMHs, also older ones, in a discharge test.
Are the discharge currents of 1A with AA and 0,5A with AAA realistic or is it to high because consumer devices with these kinds of batteries don´t use such currents?
I saw some of my older/cheaper cells have problems with 1A discharge currents and deliver lower currents, maybe because of high internal resistance
It depends.
1A seems too high for cells of that size, you would need to step up to C or D cells, but even then the usable life would be short.
It will be a trade off between how much current your device needs versus how long you need it to last.
Generally 1/10 of the capacity might be a good test current, e.g. if the capacity is 800mAh, then a discharge current of 80mA would give you plenty of data over a 10 hour test.
For hotrod flashlights then the 1 C rating discharge current might be more suitable, e.g. test a 800mAh cell at 800mA.
Hi Kennybobby,
Thank you for your answer.
I use rechargable AAA/AA-cells in many different devices, from Remote Controls to things like Flashlights, Floorlamps with Motion Sensors, so the differences are huge.
I think 1A with AA and 0,5A with AAA is a bit higher than in everyday use but otherwise I think if the cells don´t collapse or get to hot and show high voltage decrease while discharging the cells seem to be good 
And TBH, a discharge test with many cells and low current will be very time-intensive
1A for nimh aa should be perfectly fine for healthy cells , i run eneloops at 2-3A load all the time, no issues,
The ‘standard’ is 1/20 C.
A ‘good’ AA should handle 1A easily, and AAA 0.5A.
What you use depends on what results you want and what equipment you have.
In my case I have a dedicated discharger that I can ‘tune’ at 0.1v increments and change the termination if I wish. Analyzing chargers mostly constrain you to a few pre-set currents.
If my old AA can’t handle 0.5A, and AAA 0.3A, I recycle them.
The discharger also measures IR accurately and reliably. Poor cells all have high>very high resistance.
Yeah, it takes a looooong time. Nice thing about the discharger is simply set it and let it run. It stops where it’s set, and retains the capacity until it’s disconnected or reset.
Note - the cell will show it’s capability if I try to discharge it more than it can handle. I get an error code. I keep lowering the current until it starts. That’s the ‘best’ it can handle, and that usually isn’t for long. At that point if it doesn’t meet ‘grade’ it’s done, and will be recycled.
Thank you alpg88 and flydiver 
My experience is the most of my cells can handle these currents, only a few cheap/old cells have problems in this case.
I´m not sure if I can trust my Vapcell S4+ in this case because it shows full discharge speed at 1A with weak AA, The Skyrc NC1500 (max. 650mA) also always shows the selected speed,
My Opus BT-C3100 (which is limited to 700mA) shows lower currents with these weak cells and also lower current shortly before the cell reach ~ 0,90V
I think it´s more realistic but if Vapcell and Skyrc show at the end the correct discharge capacity it´s OK for me
These are the 3 chargers I use mostly for capacity tests, I don´t have such a luxurious charger like flydiver 
Not luxurious, not even terribly expensive. I have decent middle of the road analyzing chargers like the Opus and Liitokala 500, which I originally used. I got frustrated with the limitations.
Then I got one of these suggested by a BLF member.
ZH-YU ZB106+
And a holder:” 4-wire Test Stand Battery Holder “:4-wire Test Stand Battery Holder for, AA, AAA, Button Battery 5A | eBay
There are numerous similar units once you know they exist and understand what they can do. What I like about this is the flexibility and range of current discharge, the ability to do numerous kind of cells, the accuracy and reliability, and the ability to do 4-wire resistance measurements.
I find this feature compelling, which contributes to the accuracy:
[Instead of using a fixed ohm load, this type of tester uses a semiconductor to drain the battery. The fine grained control means that if you specify a 1A draw, it draws 1A, regardless of the state of battery charge. The heat is dissipated in the semiconductor, which has a large heatsink attached to it.]
In addition to ‘can’ cells I’ve cobbled together a few holders that allow me to do capacity testing on camera and phone batteries. I have found that a significant value.
Spoiler alert- pretty much ALL after market/proprietary/inexpensive camera batteries are usually significantly less than they claim (sometimes outrageous claims like poor 18650). They are seldom better, when new, than 3/4 the capacity of the original battery, often worse than the original (old) battery I was trying to replace. They generally age poorly to boot. OTOH, they are very cheap compared to true original batteries……IF you can get them. IF you CAN, those are often old stock and sometimes so poorly stored they fare no better. It’s a frustrating situation.