Repair mode on LiitoKala Lii-600 charger

Just picked up a Lii-600 charger from AliExpress. I wanted something to test the capacity on all my old rechargeables. This feature works perfectly.

What doesn’t seem to work is Repair mode which sits at 0% and stays there (it’s been several days) and looks like:

Is taking this long normal behaviour?

What does the repair mode try to repair? Is it a type of break in where the battery is charged, discharged, then charged again?

Thanks for the reply. It states in the manual:

Under auto mode the repair process for NiMH is that the system will automatically charge with 250mA current, then discharge with corresponding current, and then charge again. After several times, until the repair capacity is full.

Thing is it’s been stuck like the above for days now with 500mAh as the discharge current, 0.72V and everything else at 0.

ok, thats a break in. This normally takes 4-5 hrs but not days. I would say try another battery.

None of the channels are working or just #4? If .72V is what #4 is at try using a fully or partial charged battery. I’ve had issues with some chargers not recognizing NiMh batteries that were discharged below whatever voltage the charger recognized.

Also did you try just charging the batteries to see if that works? If it or they don’t charge then they’re probably too low and need to be brought up to a higher voltage.

Thanks yeah none of the channels are working. The charger did start working fine with channel 1 but after a while it ended up at 0% and 0.7v as well.

I haven’t tried charging them up - will try that and see what happens. :+1:

This is just a guess.

But that 794mOhms reading indicates the battery is likely in a very poor condition already.
It probably cannot properly handle 250mA charge or discharge current, which is why the voltage stays low.

Have you first tried charging the battery using normal charging mode on the Lii-600? Use the lowest charging current and see if the voltage goes up.
If the NiMh battery voltage does go up (should go to 1.4-1.5v) and becomes full, can you re-try the Repair mode to see what happens?

Oops, thanks - I didn’t even notice the internal resistance figure on the charger.

A quick bit of reading suggests that internal resistance on a health NiMH could be anywhere between 50mOhms to 150mOhms - and rises sharply when the battery hits its end of life?

I tried running a repair on the battery but the charger just showed 0% and wouldn’t budge. I did have it on auto charge but I can experiment - tbh time wise it might be better to just recycle the battery at this point.

Can NiMH batteries this old (10 years) be kept going after multiple charge/repair cycles?

I noticed that all your batteries are Duracell’s. My experience with 12 Duracell batteries was not good at all. After less than 2 years and maybe 5 charges their IR jumped to > 2000mOhm. Couldn’t be charged on most of my chargers and I tossed all but 2 of them since those still charge on a dumb charger and can be used in my low current draw tv remote control.

Edited to say that I have Eneloops from 2011 that still test out as well as Eneloops I bought in 2018, so yes 10 year old batteries can still work well depending on who makes them.

Regarding resistance reading, just sharing something, may not be exactly related…

My very first AA Eneloops (1st-gen), I think were probably from around 2006-2007), I didn’t know how to take proper care of NiMh batteries back then, and I purchased a “quick charger” (2-hour charger) thinking that I can charge them fast. (I use those batteries fairly often back when I use them in a digicam of that time). But after I don’t use that old digicam anymore, the batteries are just rarely used. Now, I just got into flashlights a few years ago, and now have various chargers including some more advanced ones like the MC3000.

Out of those 4 AA Eneloops, 2 of them have >2000+ mOhms reading (when I test using SkyRC MC3000), while one is still in the low hundred, and the other one is around 150+ or so mOhms. The “hundreds” mOhms resistance Eneloop can still be tested for capacity (I use –0.25A discharge rate) and the better one still has 1600-1700+ mAh, while the other has still around 1400 or so mAh. The 2 “thousand mOhms” Eneloops will immediately drop too low when discharging at 0.25A discharge rate. (so the discharged capacity test will show something like a few mAh only since it immediately drops to below the cut-off voltage).

(But since the SkyRC MC3000 can have user-configurable discharge current, I recall testing them at something like –0.10A or less (the lowest discharge current that the MC3000 can be configured for is –0.05A). Then those 2 Eneloops can still have a capacity reading. I don’t use these 2 batteries for anything useful, but just keep them for various “test” purposes — when used on AA flashlights, they can still power low brightness levels, but medium brightness will not be bright anymore, and High level would be similar to the “Medium” brightness (which isn’t bright)…

But for the other 2 Eneloops that have a few hundred mOhms, although when used on AA flashlights, Medium mode is still OK, but High mode won’t be that bright compared to a new battery…

Just an update - this charger is deeply unreliable in repair or test mode.

Here’s a seemingly healthy Eneloop battery which is 2 years old:

The charger gets stuck at 0% constantly, 3 of the 4 batteries here were stuck here at 0% despite giving the charger days to sort itself out.

Power cycling it causes it to recognize the battery’s actual charge, here it is after power cycling:

It then gets stuck again after a few hours.

Would recommend folks avoid this charger until they sort out its issues.

side comment: the second picture is the exact same one as the first pic, probably linked incorrectly.

Anyway, I’ve not used Repair mode much (it takes long, and maybe it can affect cycle life since it does several cycles), but I’ll try again the Test mode on the Li-600 with NiMh batteries to see if I get the same issue (I’ve tried Test mode on Li-Ion batteries on the Lii-600 and so far it seems to work fine).

My experience with the Lii-600 has also been that it handles Li-ion batteries fine in Test mode.
But now I’ve popped in a bunch of NiMH batteries in Test mode to see if I can observe the same issues too. Fingers crossed that it isn’t too bad!

I have problems with this too. Same issue.

To use Repair Mode, the battery must not be 00% charged and voltage lower than 0.2-0.3V. The device cannot correctly identify the battery parameters. When this happens I give a small charge using a common charger. When returning the battery to the Liitokala 600 the Repair Mode works normally.
You can briefly use Liitokala Charger Mode. Sometimes it works, it depends on how worn out the battery is.
Hope this helps.

See the Repair mode warning on the Liitokala website: “http://liito-kala.com/page92?product_id=23”