How to interpret this parameters about Eneloop AA

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Madeeon
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How to interpret this parameters about Eneloop AA

Hi, i have the LiitoKala Lii 500 charger, *and i’m using it to charge 4 Eneloop batteries. I have the *1900mAh AA Eneloop, but i’m confusing about some parameters and what should i do.

·*What would be the minimum and maximum voltage?* 1.2 and 1.5. What would happen if i’m over or under these values.

·I see 1900mAh, but sometimes when it’s charging i see is over 2000mAh, is that normal?

·*What would be a normal value for the mR (Resistance)?* I see these values change a lot and are not always the same. For example yesterday i get 52mR for 3 batteries and 49mR the last one.

·*What would be the best current for a discharge test.* Now i’m discharging 3 batteries at 500mA. I read somewhere something like 15C or 3C but i don’t understand what it means.

·And last one. What would happen if i forget to remove the batteries from the charger?

thefreeman
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The lii-500 terminates the charge on a voltage thresold arround 1.5V, when discharging it stops arround 1V, you can’t change these parameters.

The nimh chemistry doesn’t have near 100% coulomb efficiency unlike Li-ion (>99.5%), so it takes more than the usable capacity to charge an nimh cell. The coulomb meter of the charger is also not very accurate.

The internal resistance measurements doesn’t work on the lii-500, disregard the readings.

Lii-500 review

1C means 1 x capacity/1h , for example 2C would be 3800mA. The maximum discharge rate of the lii-500 is 500 mA. Arround 0.25C. You certainly can’t draw 15C on an Eneloop, even 3C is pushing it.

Eneloop AA test

Edit : the forum can’t handle spaces in URLs…
Fixed

zoulas
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Generally speaking, if you place the batteries in the charger, they will charge up normally. A quality charger wont let you over charge them.

If course, if you go into the settings you can change a few things but most chargers will prevent you from doing something stupid.

Marc E
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thefreeman wrote:
Eneloop AA test AA BK-3MCCE 1900mAh (White) 2019 UK.html

Edit : the forum can’t handle spaces in URLs…

Technically a browser can’t either even though it might show spaces in the address bar. Spaces are represented by the code %20 which have been dropped somewhere along the way:

https://lygte-info.dk/review/batteries2012/Eneloop%20AA%20BK-3MCCE%201900mAh%20(White)%202019%20UK.html

thefreeman
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Good to know, thanks, it was my browser who removed the %20s for some reason.

Madeeon
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thefreeman wrote:
The lii-500 terminates the charge on a voltage thresold arround 1.5V, when discharging it stops arround 1V, you can’t change these parameters.

The nimh chemistry doesn’t have near 100% coulomb efficiency unlike Li-ion (>99.5%), so it takes more than the usable capacity to charge an nimh cell. The coulomb meter of the charger is also not very accurate.

The internal resistance measurements doesn’t work on the lii-500, disregard the readings.

Lii-500 review

1C means 1 x capacity/1h , for example 2C would be 3800mA. The maximum discharge rate of the lii-500 is 500 mA. Arround 0.25C. You certainly can’t draw 15C on an Eneloop, even 3C is pushing it.

Eneloop AA test

Edit : the forum can’t handle spaces in URLs…
Fixed

zoulas wrote:
Generally speaking, if you place the batteries in the charger, they will charge up normally. A quality charger wont let you over charge them.

If course, if you go into the settings you can change a few things but most chargers will prevent you from doing something stupid.

Thank you two for the answers, just want to know which current should i select. I know it’s a safe charger but i see a lot of people discharging batteries with 1000mAh (Lithium)

It’s been 7 hours discharging 3 AA Eneloops batteries with 500mA with Fast Test option and i don’t know if i’m doing the right thing. The less voltage now from one of them is 1.04v.

jon_slider
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thefreeman wrote:
The internal resistance measurements doesn’t work on the lii-500, disregard the readings.

can you suggest a better alternative charger that works properly?

thefreeman
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Most round cell chargers aren’t very precise or accurate for DCIR measurements, that said some are able to give good enough reading to be useful, HKJ tests this in his charger reviews, IIRC : zanflare C4, BT-C3100, skyrc MC3000, Xtar vp4 plus dragon, vapcell S4+, and probably a few others. Some will underestimate or overestimate the IR but still give consitent readings so they can be compared when using the same charger. (Vapcell s4+ for example)

I have a Zanflare but I think repeatability of the measurements has worsened, maybe due to oxidation of the contacts.

jon_slider
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thanks for helping me learn more about analyzing charger options Smile

seems the Vapcel S4+ could be a good option for me

Jamisonlm3
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Quote:

What would be the minimum and maximum voltage?* 1.2 and 1.5. What would happen if i’m over or under these values.
I wouldn’t worry about it. Usually, NiMH are charged to 1.45v. If the voltage is under, it just means the battery isn’t fully charged.

Quote:
I see 1900mAh, but sometimes when it’s charging i see is over 2000mAh, is that normal?
I also wouldn’t worry about this. As long as it’s not going a ways beyond 2000mAh. Besides, don’t rely on charging mAh to tell you how much capacity a battery has. A discharge test is better for that.

Quote:
What would be a normal value for the mR (Resistance)?* I see these values change a lot and are not always the same. For example yesterday i get 52mR for 3 batteries and 49mR the last one.
I’d completly ignore the IR reading on any charger. These are known for being inaccurate and unreliable. There are better ways to measure it.

Quote:
What would be the best current for a discharge test.* Now i’m discharging 3 batteries at 500mA. I read somewhere something like 15C or 3C but i don’t understand what it means.
I usually do a discharge test of either 500mA or 1A. I wouldn’t worry about anything higher.

Quote:
And last one. What would happen if i forget to remove the batteries from the charger?
I think most chargers will trickle charge the batteries. I’m not sure what this one will do. I might charge them until they are ful and then just stop only to start to charge them again when they’ve self dicharge enough. Either way, it shouldn’t hurt them as long as you don’t leave them on too long. Eneloops are great batteries. Once charged, just take them off and store them. Leaving them on the charger over night shouldn’t hurt them.
[/quote]
d_t_a
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Quote:
Hi, i have the LiitoKala Lii 500 charger, *and i’m using it to charge 4 Eneloop batteries. I have the *1900mAh AA Eneloop, but i’m confusing about some parameters and what should i do.

·*What would be the minimum and maximum voltage?* 1.2 and 1.5. What would happen if i’m over or under these values.

·I see 1900mAh, but sometimes when it’s charging i see is over 2000mAh, is that normal?

I’m not an expert, but have done some readings here and other sites (in case something I state is not 100% correct)

Charging NiMh is sort of different than charging Li-Ion.

Assuming a battery is an empty bucket or like a sponge. (this is a very rough analogy, for illustrative purpose)

When charging a Li-Ion, it’s probably more like just a bucket – you fill in how much water to how much is the capacity of the bucket – if the water is filled to the brim, then it’s full.

When charging NiMh, it’s more like a sponge, it’s harder to estimate how “filled with water’ is the sponge, so one needs to fill more water to the sponge, and if the sponge cannot hold more water (it’s over-filled), then it’s considered “full” — one has to fill more capacity than what the container (sponge) can accommodate, to be able to find out if the container (NiMh battery) is already “full”. So, the charged capacity is higher than the capacity of the NiMh battery.

Quote:
·*What would be the best current for a discharge test.* Now i’m discharging 3 batteries at 500mA. I read somewhere something like 15C or 3C but i don’t understand what it means.

“C” is the capacity, so 1900mAh would be 1900mA (1.9Amp). I think usual discharge testing is done at around 0.2C (1/5th), so capacity test at 1900/5 = 380mA. However, different batteries/manufacturers may test in slightly different ways (depending on the manufacturer spec sheet that should mention how it tested their “capacity” rating. I think for AA NiMh, using 0.5A would be good for testing capacity.

Quote:
·And last one. What would happen if i forget to remove the batteries from the charger?

With a good charger, the battery should just stay in full condition (with slightly voltage drop, that may be normal for the battery. Although going by HKJ’s charger reviews, some chargers will have a timed trickle charge current for NiMh, while some chargers do not have a specific termination current (it continues charging but at a very low charge current, which may still not be good for NiMh batteries, but this is only if leaving them for a really long amount of time), while other chargers will completely stop charging, and some may have a tiny amount of draining the battery (HKJ’s charger reviews will generally mention this if it’s high enough to have an effect on the battery.

But otherwise, I think leaving batteries for a few or several hours (after finish charging) in most chargers shouldn’t grossly affect the battery life (again, unless HKJ mentions something abnormal after end-of-charge)