LiitoKala lii-500S - New HIT or ...?

d_t_a · 2020-07-07T08:06:23.000Z

Nisei:

I’m having a problem with a protected 18650 battery in the 500S
When it’s (almost) fully charged the charger stops and displays “null” as if there’s no battery inserted.
Is this how it’s supposed to be?
I know the 500S charges up to 4.25V so could it be the battery protection circuit kicks in before that? And is it normal for a protected battery to completely shut off when this happens?

That’s a possible explanation.

What protected battery is that?

JasonWW · 2020-07-07T09:49:17.000Z

Nisei:

I’m having a problem with a protected 18650 battery in the 500S
When it’s (almost) fully charged the charger stops and displays “null” as if there’s no battery inserted.
Is this how it’s supposed to be?
I know the 500S charges up to 4.25V so could it be the battery protection circuit kicks in before that? And is it normal for a protected battery to completely shut off when this happens?

I’m surprised you havent had many responses.
It will shut off completely on the lower voltage limit, but I dont know about the upper limit. I would assume yes. Once the cell gets up to 85% or thereabouts it should shift from Constant Current to Constant Voltage and maintain a steady 4.2 volts. Have you tried checking the voltage with a multimeter? It may not have enough accuracy, but it’s worth a try.

Nisei · 2020-07-07T12:24:21.000Z

JasonWW:

Have you tried checking the voltage with a multimeter? It may not have enough accuracy, but it’s worth a try.

My meter is accurate enough to measure this.
But do you want me to measure the voltage of the battery right after this happens or do you want me to measure the voltage when it’s still in the charger just before this happens?

JasonWW · 2020-07-07T12:35:01.000Z

Nisei:

JasonWW:

Have you tried checking the voltage with a multimeter? It may not have enough accuracy, but it’s worth a try.

My meter is accurate enough to measure this.
But do you want me to measure the voltage of the battery right after this happens or do you want me to measure the voltage when it’s still in the charger just before this happens?

Still in the charger. The battery is irrelevant, we want to know if the charger is using too high a voltage.

Maybe better yet, charge a unprotected cell and measure that voltage just before it finishes.

Nisei · 2020-07-07T12:43:03.000Z

d_t_a:

That’s a possible explanation.
What protected battery is that?

Trustfire flames 18650 2400mAh

Nisei · 2020-07-07T12:46:59.000Z

JasonWW:

Still in the charger. The battery is irrelevant, we want to know if the charger is using too high a voltage.
Maybe better yet, charge a unprotected cell and measure that voltage just before it finishes.

I’ll do both (so we also know at which voltage the protected battery shuts off).

JasonWW · 2020-07-07T16:43:30.000Z

After some research, I see HKJ tested 3 different protection circuits and they all allowed up to 4.26v. Maybe that is standard? It’s possible your charger is putting out a tiny bit higher voltage or else your protection circuits are set just a little bit lower, like 4.24v.

I imagine that’s the problem. Nothing else I can think of would cause your issue.

JasonWW · 2020-07-07T13:30:18.000Z

Nisei:

d_t_a:

That’s a possible explanation. What protected battery is that?

Trustfire flames 18650 2400mAh

Oh man, those are known to be junk. Closer to 2000mah. Review here. I would recommend different cells from a better company.

Nisei · 2020-07-07T13:47:45.000Z

JasonWW:

Oh man, those are known to be junk. Closer to 2000mah. Review here. I would recommend different cells from a better company.

I normally use Sony/Murata VTC6 batteries for vaping but I had this lying around for use in a flashlight.

Nisei · 2020-07-07T20:51:59.000Z

Unprotected battery, almost finished charging (4.249 - 4.250V)

Unprotected battery right after charging has finished.

Protected battery, charging terminated by battery's protection circuit.

Note the 4.9V after the charger displays "null"

JasonWW · 2020-07-07T16:44:03.000Z

Botton line seems to be those protected cells just don’t like the extra voltage from that charger. It’s tripping the overvolt circuit. It’s probably fine to use the battery assuming it’s not being used in parallel with other batteries like in a BLF Q8 where all cell voltages need to be super close.

Nisei · 2020-07-07T15:09:36.000Z

JasonWW:

Not to confuse resolution with accuracy/tolerance.
So just keep this in mind when trying to get these precise voltage measurements

See my post #132 in this thread

Nisei · 2020-07-07T16:04:02.000Z

JasonWW:

Botton line seems to be those protected cells just don’t like the extra voltage from that charger. It’s tripping the overvolt circuit. It’s probably fine to use the battery assuming it’s not being used in parallel with other batteries like in a BLF Q8 where all cell voltages need to be super close.

Indeed.
I just wish Liitokala would have programmed it to terminate 0.05V lower than it does now.

JasonWW · 2020-07-07T16:45:18.000Z

Nisei:

Then you should do the maths right.
0.1% of 4.254 = 0.004 plus or minus 2 counts.
So 4.254 on my meter is between 4.248 and 4.260

My bad, I was thinking 1% for some reason. :person_facepalming:

Ps, it’s not minus 2 counts, it’s only plus 2 counts.

JasonWW · 2020-07-07T16:42:49.000Z

Nisei:

JasonWW:

Not to confuse resolution with accuracy/tolerance.
So just keep this in mind when trying to get these precise voltage measurements

See my post #132 in this thread

I vaguely remember this thread. I spread myself too thin. Lol

I’ll just delete all the DMM stuff since it’s already been talked about in this thread.

Nisei · 2020-07-07T20:48:36.000Z

JasonWW:

I’ll just delete all the DMM stuff since it’s already been talked about in this thread.

Oh no not necessary. It can’t be said enough.
Too many people are thinking they can rely on what they see on their meter’s display whithout having a clue about resolution and accuracy.
But I’ve deleted some responses too.
I don’t want you to feel I was disagreeing with you, on the contrary, I want people to know about accurate readings as well (or more importantly: how they CAN’T blindly trust their meter).

Nisei · 2020-07-07T17:01:06.000Z

JasonWW:

Ps, it’s not minus 2 counts, it’s only plus 2 counts.

What I mean is:
Lowest tolerance is [displayed reading] - (0.1% of [displayed reading]) - 2 counts
Highest tolerance is [displayed reading] + (0.1% of [displayed reading]) + 2 counts
This is the same as [displayed reading] + or - (0.1% of [displayed reading] + 2 counts)

aeroden · 2020-10-28T12:25:25.000Z

My Lii-500s story: Got two of them from Bangood. On the first, the power adapter only lasted 10 seconds - refund. Got another one - this one works, but doesn’t beep (the first one does and I like beeps) - refund. Both overcharge to 4.23-4.25v as verified right after the charging finishes using MC3000, eevblog BM235, and Uni-T UT216C.

I’m quite concerned about this overcharging - a real bummer for the charger that I like a lot otherwise: the interface is really slick and the screen itself is gorgeous - much better than that of both MC3000 and Nitecore UMS2.

Both the UMS2 and tiny Xtar ANT-MC1 Plus terminate correctly between 4.20 <= V < 4.21 (and with MC3000 of course you can be as good or a bad to your batteries as you like

Does anyone know if Lii-500s can be easily modded to adjust termination voltage to 4.20?

Nisei · 2020-10-28T17:17:18.000Z

aeroden:

Both overcharge to 4.23-4.25V

That’s within tolerance specs.

aeroden:

Does anyone know if Lii-500s can be easily modded to adjust termination voltage to 4.20?

Yeah, I’ve been asking that as well but no reply so far
You’re lucky to have a spare unit unit so feel free to dissect it and see if anything can be changed

Nisei · 2020-10-28T17:22:44.000Z

aeroden:

My Lii-500s story: Got two of them from Bangood. On the first, the power adapter only lasted 10 seconds - refund. Got another one - this one works, but doesn’t beep (the first one does and I like beeps) - refund.

Wait…
So the first one only had a faulty power supply and you got a refund.
Then you got a second one that didn’t beep.
So you could have used the power supply of that unit with the first one you received right?
But you asked for a refund again? So now you have 2 units (one that’s 100% working and one that doesn’t beep and needs a power supply) for free?