LF Battery discharger AA and/or AAA that ONLY discharges.


I have multiple Opus and Lii chargers, along with some older LaCrosse 700 chargers, but I am looking for something that JUSTs dischargers the batteries so that I can then run them through the “normal test” mode on my Lii-500 to determine capacity.

I ended up buying a NightCore EA81 so that I could quickly drain AA batteries (fits 6xAA), but would prefer something that drains them individually to a safe, low voltage.

I did find this for AAA batteries: Muchmore AAA discharger

But I couldn’t find any reviews on it or how it works, and I was unable to find a similar type of option for AA batteries.

I haven’t fully reviewed all the charger manuals, but it seems that the discharge mode on most of them drains then re-charges the battery—which is not desired.

Anyone aware of other options out there?

s. I also found a 6xAAA flashlight that states 800lumens, but I am not expecting this to really drain AAA batteries properly.

I am not following you. The “nor test” on Lii-500 already does the discharging for you - that is how it measures capacity.

Why is it not desired?

FYI, my Opus C2400 will do a discharge only,if that is really what you want.


thanks for the reply. I’ll check my Opus manuals for that function. I have 2x C3400 chargers and one Ambient Weather BC-2000 charger. I don’t have the Opus 2400 charger—does the discharge option on that unit allow different Discharge only settings?

Basically, I would buy a set of AA or AAA NiMH batteries from Amazon and do a “Normal test” on them 2-3 times, either on the Lii-500 or Opus C3400 to get a mAH rating. So, when they are tested the first time, then they are fully charged when finished. The normal tests do a charge/discharge/re-charge(measure), so i need a way to discharge the batteries reasonably fast so that I could then test them again, to make sure i’m getting consistent numbers on the batteries.

What settings are you looking for?

You are mistaken on this. The measurement is done during the discharge cycle, which is the correct way to do it. At least that is how Lii-500 does it and how my Opus does it.

Ah, thanks for the clarification on battery measurement for those chargers.

For the Opus 2400, what are the options for the discharge mode? are they per slot? Also, if it does not recharge the batteries, what is the cut-off voltage, or when does it stop discharging?

I found the manual for the 2400 online, it states that the default discharge current is 200 mA (100, 200, 300, 400, 500 for NiMH/NiCd)— which seems like a good setting for AAA batteries, I also found that the C3400 has a discharge function—not sure how i missed it— similar to the 2400 where the default discharge setting is 500 mA (200, 300, 500, or 700 for NiMH/NiCd) — which is a better fit for AA batteries.

I still don’t understand why you want to discharge the cell in another charger before letting lii500 run nor test.

As for discharge voltage termination, I believe it’s 0.9V, but I would have to double check. HKJ’s review might have that info.

The new Lii-500S now has a Discharge mode, that does not re-charge after Discharge is finished, selectable 250mA and 500mA, works on Li-Ion and NiMh.
On Li-Ion, it appears to discharge to 2.80v, not yet sure what’s the threshold for NiMh discharging.

On the new Lii-500S, the Test mode will do a Charge-Discharge (only 500mA I think), then Charge again to full. It will show both the Discharged capacity and Charged capacity with the Test mode of the Lii-500S.

With the Opus BT-C3100, selecting not the Test but the Discharge mode only will just do as termed, Discharge it then stop. (no other activity after that), .9v with nimh and 2.8v with lilo, IIRC.


Rather than placing a fully charged battery into the Lii-500, then proceeding w/normal test mode, I was hoping that by “running” it for some time, or discharging it fully, that I would get more consistent results and measurements from the batteries. If not, would it be ok to run a normal test on 4xAA in the Li-500, complete, then start another normal test w/the same “full” batteries? I wanted to test new batteries at least twice, so that if I found any that were under their stated mAH, i could return them w/in the 30 day window.

thanks for the update on the Lii-500s, i wasn’t aware of a new model. At this point, would the “upgraded” C4-12 (dual button) be considered a more advanced charger for generally charging NiMH and Li-ion due to its’ ability to change current after testing for resistance during the charge?

thanks for the update on the BT-C3100, i’m still not sure why i thought that none of these had a discharge only mode.