Question to all the lii500 owners here about FULL battery detection

According to hkj review
A full AA eneloop will be detect as full in about 3 minutes only
When charging with 1000 current (because this charger use voltage termination)

Well this is not the case in my lii500
I charge my AA eneloop to full
And right after the display show END
I reinsert the battery and start to recharge again with 1000 current
It took 18 minutes to complete the charge and the display show 304 mAh put inside the battery

I then wait for about 30 minutes until the battery is cool
And put it back in my lii500 for 1000 current charge
And again it took about 20 minuts untill the charger show END
I even tried it on another slot and again same results!

During the charge i see that the voltage goes up to 1.52 and after about 4 minutes it start to drop slowly 1 volt at atime until the termination in 1.48 when the charger display END
I understand that the original review by hkj was made almost 4 years ago! So maby the new units dont use voltage termination anymore?!

my question to all the lii500 owners here
Is that happening to you as well?

gadits said:

During the charge i see that the voltage goes up to 1.52 after about 4 minutes it start to drop slowly 1 volt at atime until the termination in 1.48 when the cgarger display END

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Just to avoid confusion, I rhink you mean one hindredth of a volt (0.01v) not one volt. That's a very tiny drop in voltage, which is normal as the cell cools.
P

peter yetman said:

Just to avoid confusion, I rhink you mean one hindredth of a volt (0.01v) not one volt. That's a very tiny drop in voltage, which is normal as the cell cools.
P

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You are correct my mistake 👍

The speed depends on detection method, with voltage it can be as fast as 3 minutes, but if the battery has lower voltage* and the charger need to uses -dv/dt detection a time around 20-30 minutes is fairly normal.

*This depends on the chemistry in the battery, but can also be because the internal reference in the charger has a slightly higher voltage.

HKJ said:

The speed depends on detection method, with voltage it can be as fast as 3 minutes, but if the battery has lower voltage* and the charger need to uses -dv/dt detection a time around 20-30 minutes is fairly normal.

*This depends on the chemistry in the battery, but can also be because the internal reference in the charger has a slightly higher voltage.

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Thanks hkj
But in your review of this charger it took you only 3 minutes to detect a full AA eneloop battery with 1000 current charge
Well i use the same charger, the same battery and the same current charge, how come the results are so different?

gadits said:

Thanks hkj
But in your review of this charger it took you only 3 minutes to detect a full AA eneloop battery with 1000 current charge
Well i use the same charger, the same battery and the same current charge, how come the results are so different?

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3 possibilities:

• Internal reference in charger has a higher voltage
• Battery has slightly different chemistry (Not likely)
• Algorithms in Lii-500 has been changed.

HKJ said:

3 possibilities:

• Internal reference in charger has a higher voltage
• Battery has slightly different chemistry (Not likely)
• Algorithms in Lii-500 has been changed.

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1. I dont understand what is internal reference higer voltage in charger, can you explain?
2. I tried it with 3 different brands of battery (GP 2700, GP 2100 Recyko, sanyo 2100) and all took about 20 minutes to detect full cell
3. Do you believe liitokala change the algorithms to - dv/dt detection?

Or maby i just got a fake lii500 and not genuine!
I know its a very popular charger and many people here have it
Please people I just need an answer if that is happening in yours lii500 as well?

gadits said:

1. I dont understand what is internal reference higer voltage in charger, can you explain?

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Internal in the charger is a circuit that defines at what voltage the charger assumes the battery is full, this circuit will vary slightly between different copies of the charger.

gadits said:

2. I tried it with 3 different brands of battery (GP 2700, GP 2100 Recyko, sanyo 2100) and all took about 20 minutes to detect full cell

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None of them eneloop, then it can be the chemistry.

gadits said:

3. Do you believe liitokala change the algorithms to - dv/dt detection?

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I do not know, but manufacturers do change products without saying anything.

HKJ said:

Internal in the charger is a circuit that defines at what voltage the charger assumes the battery is full, this circuit will vary slightly between different copies of the charger.



None of them eneloop, then it can be the chemistry.



I do not know, but manufacturers do change products without saying anything.

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Thank you hkj
About answer no 2 - I tried this brands after i tried with Eneloop

I have Lii500 bought 2.5-3 years ago. Well, I charged two eneloops I have here at 1A, both half empty before the test, both not used for quite some time (several months). One is manufactured in 2010 (eneloop ver. 2), the other 2015 (Panasonic eneloop version). After fully charged, took them out and recharged at 1A. Ver 2 took 66mAh (4 min), panasonic took 293mAh (18 min). Also both charges ended at 1.54V. I have seen other charges end at 1.56V. So there isn't a fixed end voltage, mostly this looks like a -dV/dt termination.
I know the charger works fine, so it seems the case is battery condition related, perhaps the battery produces somehow different charge characteristics maybe related to age and construction, who knows. Not sure of the reason however. For the record, ver 2 indicated with 25mR and Panasonic eneloop with 38mR (the impedance shown by Lii500), all other typical NiMH I have (non eneloop) are registered as 45mR.

I'll recharge and post any further results, I'll also swap the bays used.

UPDATE: swapped the bays used, ver 2 took 37mAh (2 min), panasonic took 54mAh (3 min). So this sort of verify the case is battery related. Bays work fine. Furthermore this possibly indicate the initial 1A charge on some batteries does not result in a full charge.

apagogeas said:

I have Lii500 bought 2.5-3 years ago. Well, I charged two eneloops I have here at 1A, both half empty before the test, both not used for quite some time (several months). One is manufactured in 2010 (eneloop ver. 2), the other 2015 (Panasonic eneloop version). After fully charged, took them out and recharged at 1A. Ver 2 took 66mAh (4 min), panasonic took 293mAh (18 min). Also both charges ended at 1.54V. I have seen other charges end at 1.56V. So there isn't a fixed end voltage, mostly this looks like a -dV/dt termination.
I know the charger works fine, so it seems the case is battery condition related, perhaps the battery produces somehow different charge characteristics maybe related to age and construction, who knows. Not sure of the reason however. For the record, ver 2 indicated with 25mR and Panasonic eneloop with 38mR (the impedance shown by Lii500), all other typical NiMH I have (non eneloop) are registered as 45mR.

I'll recharge and post any further results, I'll also swap the bays used.

UPDATE: swapped the bays used, ver 2 took 37mAh (2 min), panasonic took 54mAh (3 min). So this sort of verify the case is battery related. Bays work fine. Furthermore this possibly indicate the initial 1A charge on some batteries does not result in a full charge.

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Wow thank you apagogeas
I dont understand how you say the bays is ok
When in one bay the panasonic took 18 minutes to detect full cell, and the same battery in the other bay took only 2 minutes?!

Another thing i dont understand is you think your charger use - dv/dt termination insted of voltage termination, i thought this kind of termination is supposed to be more slow at detecting full cell? and your chrger detect it fast

One last thing, you said you bougt this charger 3 years ago
And i bought my charger 1 month ago, so maybe like hkj said the newer chargers from liitokala use different algorithm

Is there anyone here with lii500 that he bought lately that can do this full battery detection test?

gadits said:

Wow thank you apagogeas
I dont understand how you say the bays is ok
When in one bay the panasonic took 18 minutes to detect full cell, and the same battery in the other bay took only 2 minutes?!

Another thing i dont understand is you think your charger use - dv/dt termination insted of voltage termination, i thought this kind of termination is supposed to be more slow at detecting full cell? and your chrger detect it fast

One last thing, you said you bougt this charger 3 years ago
And i bought my charger 1 month ago, so maybe like hkj said the newer chargers from liitokala use different algorithm

Is there anyone here with lii500 that he bought lately that can do this full battery detection test?

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I have one that is a couple of months old. IIRC, when I charge fully-charged Eneloops, they usually do take a few minutes to be detected as full. I haven't measured how long, but it does vary a bit. I think it's because the -dV/dt detection does take a few minutes to occur. The voltage limit probably only kicks in if the cell is very freshly charged and still reading 1.5v or more.

Next time I use it, I'll try it again and measure it.

But it doesn't sound like there's anything wrong with your charger.

gadits said:

Wow thank you apagogeas
I dont understand how you say the bays is ok
When in one bay the panasonic took 18 minutes to detect full cell, and the same battery in the other bay took only 2 minutes?!

Another thing i dont understand is you think your charger use - dv/dt termination insted of voltage termination, i thought this kind of termination is supposed to be more slow at detecting full cell? and your chrger detect it fast

One last thing, you said you bougt this charger 3 years ago
And i bought my charger 1 month ago, so maybe like hkj said the newer chargers from liitokala use different algorithm

Is there anyone here with lii500 that he bought lately that can do this full battery detection test?

Click to expand...

Well, given after the swap of the bays it did terminate much sooner, then it is not an issue of the bays - testing that was the primary reason for swapping the bays. If the bay/circuit was faulty or something, I would expect the same bay to always delay that much to terminate. I was obsverving voltages during all the charges and the panasonic which was detected after 18 minutes, was a slow increase of voltage. So really no reason for the charger to stop charging it. This is battery related - as voltage is only a function of the battery's state - and I leave room of 1% error the charger to actually didn't deliver 1A but something drastically lower like 300-500mA even if I set it to 1A which would result in such a delay. However the battery got relatively hot, similar to what I get when I charge at 1A so I can easily assume the battery for whatever reason whilst fed 1A slowly increased its voltage - a battery condition related outcome.
I believe the charger uses both termination methods and which one depends on the battery. Eneloops have lower IR compared to most other NiMH so whilst charging their voltage is lower, thus the charger terminates on -dV/dt since it never reaches 1.56V which is the voltage cut-off as I understand it. I have seen several other batteries, non-eneloop terminate at 1.56V. If it was only voltage terminated, it would always have to reach that 1.56V limit. It didn't happen in this case here.
And finally, of course they could have changed something at the charger's logic, however I have tested mine with the example above, it resulted in something similar to your situation and my conclusion is it is not faulty. The charger expects some signal from the battery, it could be the -dV/dt it expects to detect or a maximum voltage threshold. If the battery for whatever reason delay to produce enough voltage drop for the charger to detect that signal is not a fault of the charger; it is the battery's condition. At least in this case here I can conclude -dV/dt did kick in.

Not to derail this, but I had an 18650 battery with 4.01v and a few hours later I noticed (it was charging at 1 amp), it was super hot and only had 4.1v on it. I took it out and let it cool a day. The next day I put the battery back in and it read 4.07v and 6 hours later approximately the same 4.1v and it was super hot. Just for yuks, I put 3 more batteries in, plugged it in out side on the porch and the next day, they were all charged but one, they were all hot

The battery could be faulty. The charger cannot feed 1A constantly and have the voltage stay the same as voltage is a property of the battery, if you charge it voltage goes up. If the battery develops internal short-circuits, it is possible to charge it at 1A and also have a voltage reading staying the same all the time, all the charge put in gets consumed at the short circuit which also makes the battery very hot too. Now if the charger is faulty and the voltage it assumes it reads got stuck, that's another issue but in the discussion above we don't have a stuck voltage reading anyway, so very unlikely the OPs system to be faulty too.

With the same eneloop battery i did 2 NOR test
One with 500 current discharge and one with 250 current discharge, and here are the results
500 current - show the battery have 2127 mAh
250 current - show the battery have 1973 mAh only
Which test is more accurate?

gadits said:

...
500 current - show the battery have 2127 mAh
250 current - show the battery have 1973 mAh only
Which test is more accurate?

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I'd always suggest to use the 500mA discharge capacity for AA (700mA setting to keep heat during charge lower) which reveals if a battery can sustain a more worthy current so the value you get is more relevant to moderate-high drain devices. I'd use 250mA discharge (300mA setting for the same heat issues) for AAA batteries however. Recall that NOR is not a scientific measurement test. I use it to compare the quality of the battery over time and to match batteries, so if it degrades from older NOR tests I can downgrade the battery to other services. I'd typically use break-in from maha mc9000 for a more accurate capacity but it takes too long so I use NOR over the last 2 years. Works pretty well in my battery data.

The reason you may see a 500mA return more capacity is because the battery got heated more during discharge (including more heat from charge if set to 1A) and this results in lower IR. If I was to design NOR, I'd let the battery cool off after the initial charge to remove this lower IR effect from charging. Low drain applications don't care for IR but in the case of eneloops, this looks strange in my eyes. I expect older batteries to behave like that, with somehow elevated internal resistance. If you want the best possible NOR measurement, charge the battery beforehand, let it cool off and then start the NOR test. This will produce the lowest heat from the initial charge of NOR. It will get warm but not as much as doing a partial/full charge as part of NOR right before the discharge takes place. Finally, don't rule out a contact quirk. Try to clean the terminals just to rule out this situation and when you insert any battery, rotate it slightly, it will help make the best contact.