Battery usage: problem or not?

[numsquat]

Using an Alien 220w. I've noticed a few weeks ago on my Alien screen that I've been pulling more on battery B than A. I've tracked on my eleaf Luc 4 charger that the battery B initially shows up to a .3 difference (has ranged from .12 to .3) from A when put on the charger. Just wondering if this is an issue or not.

I have three paired sets of batteries for the Alien and have started switching the batteries in the Alien after charging (the battery that was in slot A is moved to slot B, flip flopping after each charge).

 

[Barkuti]

You mean the Efest LUC v4 charger (HKJ's review of it)? Not a raving review, I'd say. Overvolted the cells a good bit, this results in more available energy but noticeably lesser lifespan.
Rotating the slot is a good idea. If you believe a given slot puts more strain on its cell, just keep the “healthy” one there for a while and keep an eye over the stuff to see what happens.
That voltage difference you pinpoint appears just after the mod cutoff? The deeper an in-series cell configuration is discharged, the more prone to show some sort of cell potential difference after cutoff (the lower volts cell being the weakest link). For well matched cells in every aspect (including wear and tear) such delta oughts to be quite small.
Certain chargers can do charge and/or discharge tests. This can be useful to classify/bin cells if you have multiple sets, re-pairing/teaming them based on their measured capacity under same discharge conditions (for same type of cells, of course).
And no, don't worry about your mod's cutoff value. Your cells are fine with it.

Cheers

 

[SteveS45]

What brand and model batteries are you using in your Alien?

 

[Topwater Elvis]

Efest revised the v4 charger in late 2013, since then (2014 forward) it is one of better inexpensive chargers.

At the top of the page of HKJ's review in red letters click on;
" Efest has modified this charger and a update review has been published." for confirmation.
Or click here---> Review of Charger Efest LUC V4 2014

It is quite common in multi cell power devices for cells to discharge slightly unevenly. Rotating battery position is a good practice.

Be sure you're using quality name brand cells with a sufficient CDR to support the power ranges you use.
Only buy batteries from reputable vendors / dealers to avoid counterfeit & re wrapped lesser quality cells.

 

[numsquat]

It's a Efest LUC v4 charger purchased new 03/17. Batteries are LG HD4, all six purchased same time from imrbatteries.com 03/17. The (up to) 0.3v difference is a reading from the Efest.
In thinking more about it today I think my concern was more that something is wrong with the Alien more than I think it's a battery problem, if there is actually a problem. Sometimes my brain will worry about things it shouldn't. I've not had any "issues" with the Alien. It's also my first external battery mod, new to using 18650 batteries, etc, so still learning about some of this stuff.

 

[DaveP]

It's a Efest LUC v4 charger purchased new 03/17. Batteries are LG HD4, all six purchased same time from imrbatteries.com 03/17. The (up to) 0.3v difference is a reading from the Efest.
In thinking more about it today I think my concern was more that something is wrong with the Alien more than I think it's a battery problem, if there is actually a problem. Sometimes my brain will worry about things it shouldn't. I've not had any "issues" with the Alien. It's also my first external battery mod, new to using 18650 batteries, etc, so still learning about some of this stuff.

Have you read the battery voltages with a digital meter just to see what it says after charge and after you see variances reported by the mod? Just curious. I see differences in my matched triple sets in the Wismec RX200S, also. It's not an issue if the variances are small. Batteries aren't absolutely the same in charge and discharge rates and we see those differences when we read them in a dual or triple mod that has the battery voltage feature.

When you buy batteries at the same time and use them in pairs or triple sets as a dedicated set in a mod, they should be repeatable, but just because you bought them together doesn't mean that they will discharge exactly alike when used in sets. That's likely due to manufacturing variances.

I'd be interested in seeing a reading taken followed by another reading after rotating or removing and replacing the batteries. It's not uncommon to see contact resistance cause varied readings. That also happens in chargers. I can't count the number of times I've jiggled a battery in a charger and saw the reading change. That can happen in a mod, also.

Just a thought.

 

[numsquat]

I'd be interested in seeing a reading taken followed by another reading after rotating or removing and replacing the batteries. It's not uncommon to see contact resistance cause varied readings. That also happens in chargers. I can't count the number of times I've jiggled a battery in a charger and saw the reading change. That can happen in a mod, also.

Next time I charge I'll pull them out and then recheck. I usually roll the batteries in the charger when I put them in to make sure they're set good. But never took out/replaced and took another reading. Don't have a digital meter to check with.

 

[DaveP]

We all have at least one of these for quick checks.

7 Function Digital Multimeter

Or this one for around the house. It's a loose Chinese Fluke 87 clone with good build quality and performance for a cheap price.
11 Function Digital Multimeter with Audible Continuity

 

[Barkuti]

That cheapass multimeter from Harbor Freight seems to be another DT-830B/D clone, which can be found in Aliexpress for even less than $3.50 including shipping. Ouch quality level, suffice to say, though it may do 0K for measuring battery voltages.

The Uni-T UT120C/B/A is a nice, compact and inexpensive device: Uni-T UT120C review and tear down @ EEVblog Electronics Community Forum
In Aliexpress for as low as $11 - 12.

Cheers

 

[numsquat]

Thanks for the suggestions on meters, use to have one but thinking one of my boys grabbed it some time in the past, probably need to pick one up.

Did some testing. Did the put batteries in charger/take out/put back in. Did get some slight difference in readings. What I did find interesting was I pulled batteries twice when I had two bars left on the Alien versus one bar, when I have been pulling them out. both times both batteries were within less than .06v each other. Thinking as I get close to the 2.8v (which I think is the Alien's cut off) the Alien may be pulling more from one battery, draining it more than the other. Thinking I'll continue to pull at two bars left for a while and see what the results are.

 

[Mooch]

Thanks for the suggestions on meters, use to have one but thinking one of my boys grabbed it some time in the past, probably need to pick one up.

Did some testing. Did the put batteries in charger/take out/put back in. Did get some slight difference in readings. What I did find interesting was I pulled batteries twice when I had two bars left on the Alien versus one bar, when I have been pulling them out. both times both batteries were within less than .06v each other. Thinking as I get close to the 2.8v (which I think is the Alien's cut off) the Alien may be pulling more from one battery, draining it more than the other. Thinking I'll continue to pull at two bars left for a while and see what the results are.

All batteries are slightly different from each other. These differences are most apparent when nearing empty. Even when discharged by the exact same amount, as in all series mods, they will end up at different voltages.

 

[numsquat]

All batteries are slightly different from each other. These differences are most apparent when nearing empty. Even when discharged by the exact same amount, as in all series mods, they will end up at different voltages.

Good to know, wasn't freakin' out about it but was a little concerned maybe the Alien wasn't working right.

 

[nalo_b]

My alien shows b slightly lower than a even with fresh batteries. But most of the time the batteries are the same voltage when I pull them out. But I do notice that sometimes one is lower like yours though and that is with 3 different pairs of batteries

 

[DaveP]

That cheapass multimeter from Harbor Freight seems to be another DT-830B/D clone, which can be found in Aliexpress for even less than $3.50 including shipping. Ouch quality level, suffice to say, though it may do 0K for measuring battery voltages.

The Uni-T UT120C/B/A is a nice, compact and inexpensive device: Uni-T UT120C review and tear down @ EEVblog Electronics Community Forum
In Aliexpress for as low as $11 - 12.

Cheers

I have those cheap harbor freight meters scattered around the house and a couple in my basement workshop. Sometimes, they give you one with a coupon or free with a specified purchase amount at checkout. Usually, I just want to check continuity or battery voltage. Those are good for that.

I find few instances where I need to go and grab my Simpson digital meter.