Marrying used batteries...

[Mythical_OD]

So for a while I was using single 18650 mods, and as such I had a VTC4 for each of them. But lately Ive found myself with more 2, 3, even 4 18650 mods, and now Ive got 4 or 5 batteries wrapped up in single battery mods that barely ever get used anymore.

So the question, I know buying fresh, new batteries and using them and keeping them together for their life is ideal, but Id like to combine some of the singles I have into sets, so how safe really is it? I know the marrying thing is more a general rule of thumb more than a set in stone must. The batteries Ill be matching up havent really been through that many cycles or that much use compared to some. Is there a way to measure their internal resistance and capacity to better match them?

Any help with this subject would be appreciated. Really dont wanna have to spend another $40 on batteries to have a couple extra sets for my Hohm Wrecker and Noisy Cricket (unles Vape 101 runs their 2 for $8 deal again on the VTC4s lol)

 

[inspects]

If you have two (of the same) charged batteries and let them sit overnight, then check them with a multimeter in the morning and find they're very close, I wouldn't hesitate to use them.

 

[Mythical_OD]

As far as the multimeter, what are you checking for? Resistance or Voltage? Ive got a Luc V4 charger that displays the voltage of the batteries when they are inserted, not sure how accurate it is though. Im sure Ive got a multimeter in a drawer somewhere with all my soldering and wiring stuff though.

 

[OBDave]

Personally not something I'd do - Mrs. Dave and I had a dozen or more single cells that just sat around for a year and a half after we started using dual-cell mods because I didn't want to guess at the charge cycles to gauge equivalents, even though we both labeled our cells 1, 2, 3... to use them roughly the same amount of times, even though the higher numbers went into service later and we didn't track that. I kind of thought it was a waste, but then I started picking up some single-cell compact regulated mods and they've found new life.

I don't necessarily need different cells for every mod, though - I've got four pairs right now that are all married, but I'll cycle them through whatever dual-cell mod I'm using at the time, whether it's an IPV5, Sig 100, K120, whatever...

 

[OBDave]

As far as the multimeter, what are you checking for? Resistance or Voltage? Ive got a Luc V4 charger that displays the voltage of the batteries when they are inserted, not sure how accurate it is though. Im sure Ive got a multimeter in a drawer somewhere with all my soldering and wiring stuff though.

The LUC4 only measures to the tenth - not super accurate. And I'm not sure just a single overnight under no load would produce enough change to say with confidence they share similar discharge patterns. I'd be looking to measure at least to the hundredth after three or four days sitting around to see if there's a noticeable change. I'm no battery pro, I just always recommend an abundance of caution.

 

[Mythical_OD]

The LUC4 only measures to the tenth - not super accurate. And I'm not sure just a single overnight under no load would produce enough change to say with confidence they share similar discharge patterns. I'd be looking to measure at least to the hundredth after three or four days sitting around to see if there's a noticeable change. I'm no battery pro, I just always recommend an abundance of caution.

My Luc V4 measures to the hundredth (x.xx), but Id just use a multimeter. But Ive read a bit about marrying batteries after some use and basically heard its doable and the "always start with fresh sets" thing is overblown to keep noobs safe. I mean, even new, married sets are gonna have some differing discharge rates. As long as they arent too drastic there shouldnt be an issue, and most modern regulated mods have a voltage difference safety feature (though obviously the cricket does not).

 

[OBDave]

My Luc V4 measures to the hundredth (x.xx), but Id just use a multimeter. But Ive read a bit about marrying batteries after some use and basically heard its doable and the "always start with fresh sets" thing is overblown to keep noobs safe. I mean, even new, married sets are gonna have some differing discharge rates. As long as they arent too drastic there shouldnt be an issue, and most modern regulated mods have a voltage difference safety feature (though obviously the cricket does not).

I gear all of my serious posts to be read with an abundance of caution, particularly for the reason a noob might stumble across them in the archives one day. That said, depending on the use you've gotten out of them and how lightly they've been used, you can probably get away with it. Batteries from the same batch that have 20-30 charge cycles through them independently? Absent any boneheaded incident like discharging down to 3.0 or 2.9 (it's happened to me a couple times in my mech-tube-and-bar-visiting days), you're probably 99% safe. Completely different cells, where one has 50 charge cycles through it and the other 100? Maybe not the same thing...

 

[Mythical_OD]

Well I have 2 batteries in particular that Im thinking of starting with trying to marry and both have gone through under 20 cycles. They are in mods I dont use all that much. In fact, all 4 of the batteries are pretty "new", meaning they didnt see much use. Id say none of them have over 30 cycles on them.

 

[inspects]

As far as the multimeter, what are you checking for? Resistance or Voltage? Ive got a Luc V4 charger that displays the voltage of the batteries when they are inserted, not sure how accurate it is though. Im sure Ive got a multimeter in a drawer somewhere with all my soldering and wiring stuff though.

I check the voltage with the multimeter. Have also rechecked the voltage after using the batteries for a few minutes to make sure their discharging equally.

 

[inspects]

Well I have 2 batteries in particular that Im thinking of starting with trying to marry and both have gone through under 20 cycles. They are in mods I dont use all that much. In fact, all 4 of the batteries are pretty "new", meaning they didnt see much use. Id say none of them have over 30 cycles on them.

I'm just saying what I would do....use them....others may not like the idea, everyone has their own opinion.

 

[inspects]

Some folks take the marrying a little too far....hell, you don't really know what married batteries might do at any given moment. But we're talking about the same thing here, like you said, less then 30 cycles...they're basically new.

 

[OBDave]

Well I have 2 batteries in particular that Im thinking of starting with trying to marry and both have gone through under 20 cycles. They are in mods I dont use all that much. In fact, all 4 of the batteries are pretty "new", meaning they didnt see much use. Id say none of them have over 30 cycles on them.

Based on that limited use, if they're of the same age and type I'd just try and marry them, and monitor their charge levels when they hit the charger for any irregularities. Efest must have changed the LUC though, my year-old version only measures to one decimal point - if there's a new one that goes to hundredths I'd guess that it's fine to use, as it's my understanding Xtar makes their chargers anyway.

 

[vap3r]

From least to most accurate/expensive...

1. Opus BT-C3100/C4000
2. R/C Hobby Charger (e.g. HiTEC X4)
3. R/C Hobby Charger + 4-Wire ESR Meter
4. R/C Hobby Charger + 4-Wire mΩ Meter

For our needs, the Opus BT-C3100/C4000 will generally suffice.

 

[Ryedan]

I'm just saying what I would do....use them....others may not like the idea, everyone has their own opinion.

FWIW, I agree and have done the same.

 

[CraigVM62]

I would also add to not order a 5 dollar multimeter off of ebay or pick up the cheapest offering from Harbor Freight for testing batteries Over the years I have hired many new to our industry which requires metering voltages that must often be within spec by .10 of a volt. When they show up with such a meter we just do them a favor and toss them in the garbage. It is scary how far off readings can be with them. While I have found you do not need to spend Fluke or Gossen prices to get a decent MM as spending even $30 will provide good accuracy and will pay for itself with even small projects and tasks.

 

[Ding]

I have some LG2 brown 3000 mah batteries that was used in a single batt mod, less than 10-15 recharges/cycles on them of not half used.have the second gen nitecore i4 that I've been using.have 2 RX200S's just received...put fresh lg HE4's in one but wanna use the LG2' as I have 6 of them.two still new in box and new one coming for a 3 package set.Bought from reputable dealer.All this talk of "gotta have new" is well, confusing.so less than say,30 cycles are still considered new,I should be GTG.?.....would like to get the Xtar 4 bay just cuz I likes gadgets and bought some battery rewraps just to distinguish the used ones from the NIB which will stay brown.

 

[fq06]

Within 30 cycles won't be much of a difference just keep the he4's with the he4's and the lg2's with the lg2's.

 

[Mythical_OD]

So today I threw 2 of the non married batteries in my Sigelei 213 to see how theyd do together. After a full day at work vaping on breaks and lunch and in the car and some time at home, the batteries are sitting at 3. 8 and 3.84, which even my married sets usually varied about that much or more after a full day.

So my conclusion drawn from this? Having the rule of marrying fresh batteries and not mixing and matching is a good rule to keep noobs from doing stupid things, but if you know your shit you can totally get away with it. But its only 1 day so who knows whatll happen over time, but Im gonna keep them together for the Sig 213. The fact that it shows independent battery voltages on the screen makes it an ideal mod to try this on.

Stay tuned for my future thread entitled "I tried to marry old batteries, my face got blowed up" lol

 

[Belanger]

Old post but still valid as I came across this and many others will to, you should not be trying to marry them yourself if you don't even know what your testing for your a danger to everyone around you.

Also the klon sucks ass, and the mystic overdrive is that much worse. I see your very much a bandwagon kind of guy

Ps I'm an electrical engineer and I can safely say you do not know your shit, at all. Where your arrogance comes from I don't know but you are one of these noobs you speak of keeping safe.

No mentioned of proper battery safety here at all, is your mod wired in parallel or series? Because if it's series don't forget to cycle the position of your batteries each time you take them out to charge as well

Why don't you connect a load, and a scope and Measure the discharge curve correctly, instead; you use a $10 harbour freight meter to measure. The funny part is your confidence in your knowledge and capabilities.

 

[r055co]

Just one word -

Don't

Now four -

Don't be fucking stupid

Sent from my Pixel 3 XL using Tapatalk

 

[BoomStick]

Old post but still valid as I came across this and many others will to, you should not be trying to marry them yourself if you don't even know what your testing for your a danger to everyone around you.

Also the klon sucks ass, and the mystic overdrive is that much worse. I see your very much a bandwagon kind of guy

Ps I'm an electrical engineer and I can safely say you do not know your shit, at all. Where your arrogance comes from I don't know but you are one of these noobs you speak of keeping safe.

No mentioned of proper battery safety here at all, is your mod wired in parallel or series? Because if it's series don't forget to cycle the position of your batteries each time you take them out to charge as well

Why don't you connect a load, and a scope and Measure the discharge curve correctly, instead; you use a $10 harbour freight meter to measure. The funny part is your confidence in your knowledge and capabilities.

Crawl back in your hole and never come back here.

 

[The Cromwell]

Try out ther unmarried batteries starting with a full charge in each one.
When you need to recharge them read the voltage of each one with a DVM or a charger that displays the voltage.
If they are pretty close to the same voltage you should have no big problems.

 

[SteveS45]

Be careful who you take advice from because a little research will show you that what they suggest is not what they suggested just a few days ago~! A few things to consider is the age you know about the cells and charging cycles you already used then for. If it is close and the standing voltage is the same that is just one of the things to consider. Good Luck~!

 

[Jinx'd]

I have 4 one batt mods. I am not about to buy 1 batt just for each. I grab whatever, use it, charge when I'm finished with it.
then the next time I use that 1 batt mod, I grab the other of the pair.

 

[Just Frank]

I just buy more batteries. Someone wise, long ago told me, "Skimp on batteries you do not." So I have married sets and singles. I've split up marriages, but don't start new ones. That's just me though. I saw a dude with a RX a couple of years ago that had different brand (18650s) in his mod. I had a married set with me and offered to trade him. He refused because one of them was a "$20 Efest". So I just gave them to him and told him how to use them.

 

[Jinx'd]

told him how to use them.

that went in one ear, and out the other.

while I do use singles from pairs, I ALWAYS keep the pairs together when using 2. I WILL NOT put a Moli with an LG, for example.

 

[The Cromwell]

yep all paired batteries should be same brand an model number at a minimum requirement.

 

[Jinx'd]

yep all paired batteries should be same brand an model number at a minimum requirement.

and I would not put an old with a new.

 

[The Cromwell]

and I would not put an old with a new.

They ideally should be about the same age and number of charge discharge cycles.

However that depends on several factors. 1 of which being how hard you are going to push the "married" cells.

Close to the same capacity and internal resistance is the main considerations.
ie if married batteries discharge at the same rates then they are fine together.
If after discharging there is a noticeable voltage difference in the cells then you may have an issue or maybe the mod just works one cell harder than the other? For instance runs the display off of one of the cells?

Even 2 premium brand new cells of the same brand/model will not usually be an ideal match. Most often acceptable but seldom identical.

 

[The Cromwell]

Mooch even kind of rolls his eyes and shrugs when talking about hardline rules for married cells.