Relationship between capacity loss and Inability to push original amp output.

Can anybody explain in a simple way the relationship and ratio if possible, of capacity loss and a batteries inability to push amps as it once did?

Here’s the reason why.

My modified TN42 with CFT 90.2 needs more than 10 amps to run on max output. It proved that when I first got it and MJ1’s and GA’s would step down within 10 seconds upon turning the light on. So I got high drains. P26A and 30Q. They worked fine for close to 2 years. With no step down in the beginning and only stepped down due to battery depletion.

When both of those batteries got to be close to 2 years old they would do the same thing as the 10 amp batteries I mentioned above. They lost capacity as expected, in addition, it appears it has also lost the ability to push the original amount of amps. They would start stepping down Within 5 Seconds or so of turning the light on. The 30Q’s are in there now and it’s been doing that for close to 2 months.

What eventually happens with the 30Q, after five, six or seven step Downs from turn on, it will eventually lock into Turbo.

I don’t get that?:thinking:

To confirm that it was the batteries, I put brand new VTC5D and 25S and used it on the trail and they worked fine. No step-downs until battery depletion.

Just to reiterate my two questions.

  1. Why would older High drain batteries step down 5,6,or 7 times from turn on and then lock into Turbo?

  2. The relationship and ratio if possible, of capacity loss and a batteries inability to push its original amps?

Thx

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Li-Ion cells have a limited lifespan, typically measured in recharge cycles. This is normally numbered in the 500 times range. Full recharge cycles are the ideology. Small depletions and recharged add up to a full cycle, and so on.

There is damage done, as I understand it. Akin to us smoking. Incremental breakdown of the transfer structure and crystalline growth can also occur which blocks energy transfer. Oftentimes this crystalline growth will burst a cell or battery pack.

I’ve had quite a few cells refuse to register on the charger, after a decade of using Li-Ion in hard use scenarios I’m up to about 12 that have expired, one even while in use! Out of over 300 that I’ve bought.

I like to rotate in new cells for my most in-demand lights annually and rotate those year old cells down into less demanding units. Married cells in a multi-cell light get dispersed into lower demand lights. Ultimately, of course, they will all get replaced. That said, I still have usable 18650’s from 2014.

Hope that helps, I realize my comparatively low knowledge ( or retention) of how Li-Ion cells work leaves a lot to be desired.

Accounting 101, depreciative value estimation. Buy the best so they can be repurposed when diminished. Buy lesser to start and the value is soon too low to use at all. :wink:

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^^^

Thanks.

I’m hoping to get my two questions answered. The first one maybe the more difficult one.

Second question is probably also a tough one. I don’t think there’s any doubt that the ability to push amps declines as the battery ages. I just wonder how that’s related to the capacity loss?

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Internal resistance goes up over time. More resistance, less amps.

Take a look at BU-808b: What Causes Li-ion to Die? - Battery University
and BU-808: How to Prolong Lithium-based Batteries - Battery University

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Thanks. That makes sense. I forgot about internal resistance.

Does capacity loss and inability to push amps decline at the same rate?

I will check the links.

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Minding Your mAhs Ep028 – What causes a Li-Ion battery to suddenly fail?

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I did internal resistance test on my Opus and my Vapcell.

I don’t think they’re that accurate. The numbers between the two of them are a lot different.

Vapcell. Two tests . 25 month old 30Q.

Test one. 54, 56, 62 and 71.

Test Two. 60, 60, 71 and 90.

OPUS. Same batteries.

Test one. 86, 114, 119 and 120.

Test Two. 86 ,118, 127, and 137.

Out of the two I’m not sure which one is more accurate.

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Yeah, internal resistance testing on a cheap charger is notoriously unreliable … just good enough to see a trend.

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Take a multimeter, set it on Ω - resistance and check the internal resistance of the battery !

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This man knows very much about batteries, check out his videos in general, you can find some nice informations… !

Minding Your mAhs – Ep021 – What is battery voltage “sag”?

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Thanks for all your suggestions.

I don’t think someone’s going to have an answer for number one question in my thread.

Number two question has been mostly answered.

Anyone?!

  1. Does capacity loss in a battery and it’s inability to push amps decline at the same rate?

My knowledge regarding this Hobby, is average.

Where I excel are my questions.

I’ve actually stumped Physicians and veterinarians with questions. The honest ones say I don’t know , the dishonest ones try to BS me!

I see that symbol there but when I put the probes on it it doesn’t register anything.

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When you put them on the positive and negative of your battery… !?

They work fine when I check the voltage I’ve done that thousands and thousands of times I’m a fanatic about voltage. Off the charger after I use the light and when I use the flashlight again.

Maybe that setting is not functioning? I don’t know.

After I take Nikko out I’ll take a picture of my DMM.

There are more than one port for the probes there’s three ports

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I left the wires in the same spot as it is for when I do my voltage. I’m assuming that’s correct.? There’s a port in the center.


That doesn’t seem right. The middle black port is labeled COM for common, so you probably always want one probe in it. The left port is labeled DC 10A so it is probably for measuring current. I see V, ohms and mA over the right port, so you probably want to use it for everything else.
So it looks like you want to use the middle and right ports.

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Is that the case for a Lithium-Ion batteries? Hope you read that warning. Says the circuit has to be dead! I’m guessing for Batteries it’s safe?

I think you may be right I’ll try that. I think it mentions that in the manual. I’ve had them hooked up the wrong way for 4 years!

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It still doesn’t work for resistance. All zeros across the board. I put the leads in as you said and in the diagram. No dice

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Yeah put it in the middle, and then probably if you touch the ends of the cables, you should can read the internal resistance of the multimeter… !? Then test it on a battery… !