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When pointing to and quoting the SMC article how does it not imply they disapprove of running series?

Where am I being argumentative? In my earlier posts I simply stated it would be nice in having a test between the lifespan of each configuration.
Then I was asked to run my batteries and I would see a significant difference between them, showed my results in which I didn't.
Then I repeated that wouldn't it be nice to have some test showing the difference.
How is asking for some sort of time frame test of lifespan expectancy showing the difference being argumentative? I think it would be informative.



Connecting 6 cells in one single battery will have far less resistance than running two batteries in series. That's a fact.
This comment sounds like sarcasm. Where in my posts am I disagreeing with the difference in resistance?
In my post I actual say there is more resistance in a series setup.
Everything I read is just about "why" because of resistance which theoretically is correct in that resistance hinders performance.
...
Don't forget to add in the connectors resistance in the graph. Some connectors are much worse than others.



The only thing I've continued to mention is wouldn't be nice to actually know what to expect in the difference in life expectancy.
 
The only thing I've continued to mention is wouldn't be nice to actually know what to expect in the difference in life expectancy.

  • Configuring LiPo batteries in series for RC applications, while offering a voltage boost, introduces several challenges that can significantly compromise the batteries' longevity and safety.
    1. Amplified Electrochemical Stress: Series configurations exacerbate stress on the batteries due to potential mismatches in cell impedance, charge states, or capacities. This heightened stress accelerates chemical degradation, curtailing battery lifespan.
    2. Risk of Voltage Imbalance: In a series circuit, the uneven discharge of cells can lead to over-discharge in one while others remain active. This not only strains the over-discharged cell but also increases the risk of irreversible damage, making it a risky practice.
    3. Heat Generation and Management Issues: The increased heat output in a series setup can accelerate wear on the LiPo cells. Consistent exposure to high temperatures can cause internal resistance to rise, further diminishing battery efficiency and safety.
    4. Battery Management System (BMS) Strain: Ensuring uniformity and balance in a series configuration requires a more sophisticated BMS. This adds complexity and increases the risk of system failure, which could lead to reduced performance or even safety hazards.
    5. Performance vs. Longevity Dilemma: While the performance gains from a higher voltage setup are evident, the trade-off comes in the form of reduced battery life and potential safety concerns. The increased power output can be overshadowed by the shortened lifecycle and additional maintenance requirements.
    To estimate the added degradation from running LiPo packs in series, you could consider the following factors:
    • Internal Resistance Rise: Regularly measure the internal resistance of each cell. An increase in internal resistance is an indicator of degradation.
    • Cycle Count Impact: Track the number of charge-discharge cycles. Batteries in series might reach their cycle life limit faster due to increased stress.
    • Temperature Monitoring: Monitor temperature during operation. Elevated temperatures can be used to extrapolate accelerated degradation rates.
    A rough estimation formula could be:Estimated Degradation Rate=Base Degradation Rate×(1+Stress Factor)×Temperature FactorEstimated Degradation Rate=Base Degradation Rate×(1+Stress Factor)×Temperature Factor

    Where:
    • Base Degradation Rate is the normal degradation rate per cycle for a single battery.
    • Factor quantifies the added stress from series configuration (e.g., mismatched cell conditions).
    • Temperature Factor represents the increase in degradation rate due to higher operating temperatures.

    This formula provides a basic framework to gauge how much more quickly a battery might degrade when run in series compared to a standard setup. However, precise calculations would require specific data from experimental or field conditions.

 
  • Configuring LiPo batteries in series for RC applications, while offering a voltage boost, introduces several challenges that can significantly compromise the batteries' longevity and safety.
    1. Amplified Electrochemical Stress: Series configurations exacerbate stress on the batteries due to potential mismatches in cell impedance, charge states, or capacities. This heightened stress accelerates chemical degradation, curtailing battery lifespan.
    2. Risk of Voltage Imbalance: In a series circuit, the uneven discharge of cells can lead to over-discharge in one while others remain active. This not only strains the over-discharged cell but also increases the risk of irreversible damage, making it a risky practice.
    3. Heat Generation and Management Issues: The increased heat output in a series setup can accelerate wear on the LiPo cells. Consistent exposure to high temperatures can cause internal resistance to rise, further diminishing battery efficiency and safety.
    4. Battery Management System (BMS) Strain: Ensuring uniformity and balance in a series configuration requires a more sophisticated BMS. This adds complexity and increases the risk of system failure, which could lead to reduced performance or even safety hazards.
    5. Performance vs. Longevity Dilemma: While the performance gains from a higher voltage setup are evident, the trade-off comes in the form of reduced battery life and potential safety concerns. The increased power output can be overshadowed by the shortened lifecycle and additional maintenance requirements.
    To estimate the added degradation from running LiPo packs in series, you could consider the following factors:
    • Internal Resistance Rise: Regularly measure the internal resistance of each cell. An increase in internal resistance is an indicator of degradation.
    • Cycle Count Impact: Track the number of charge-discharge cycles. Batteries in series might reach their cycle life limit faster due to increased stress.
    • Temperature Monitoring: Monitor temperature during operation. Elevated temperatures can be used to extrapolate accelerated degradation rates.
    A rough estimation formula could be:Estimated Degradation Rate=Base Degradation Rate×(1+Stress Factor)×Temperature FactorEstimated Degradation Rate=Base Degradation Rate×(1+Stress Factor)×Temperature Factor

    Where:
    • Base Degradation Rate is the normal degradation rate per cycle for a single battery.
    • Factor quantifies the added stress from series configuration (e.g., mismatched cell conditions).
    • Temperature Factor represents the increase in degradation rate due to higher operating temperatures.

    This formula provides a basic framework to gauge how much more quickly a battery might degrade when run in series compared to a standard setup. However, precise calculations would require specific data from experimental or field conditions.
I'm not following how this answers my simple question to "would it" or "would it not" be interesting info. I think it would be interesting. Similar to how SMC's PowerFactor number is interesting in comparing under load against other batteries they have. I find it to be good decision info to have.

The first half down to line 5 comes across as it's nothing but a safety concern having batteries in a series configuration. If it's a safety concern to do the test it would also be a safety concern to run them in a RC application. If that's how you feel about running dual series batteries why not come out and say it?
The second half reads as to how some factors for a test should be recorded. Those same factors should be used when testing any battery.

I'm really at a loss here. I don't understand how the last couple of comments are warranted. I never said one way is better than the other. I asked a simple question of opinion, would a comparing test be something that other than myself would be interested in seeing. I would think anyone weighing the pros and cons if they should get dual or single batteries would appreciate the information. Instead of an answer there is a repeat of a single battery is better than dual series batteries. Again how does any of this relate to answering?
 
I'm not following how this answers my simple question to "would it" or "would it not" be interesting info. I think it would be interesting. Similar to how SMC's PowerFactor number is interesting in comparing under load against other batteries they have. I find it to be good decision info to have.
You're not following the answers because your question seems to change every time someone answers one of them. That's why WF said you're being argumentative. If you want test results, then I suggest you get to testing. IDK how else you think you're going to get that information. Your question from the previous post was "What can be expected in the difference in life expectancy?", which I attempted to answer.

The first half down to line 5 comes across as it's nothing but a safety concern having batteries in a series configuration.
Maybe because they're are safety concerns and other concerns also? Not sure how you don't seem to grasp that.

If that's how you feel about running dual series batteries why not come out and say it?
I have stated how I feel about running dual LiPos in series several times now. Just because you can't accept that answer doesn't negate my answer.

The second half reads as to how some factors for a test should be recorded. Those same factors should be used when testing any battery.
The second half was an answer to your previous question, "What can be expected in the difference in life expectancy?". It's a simple formula, but once again, you don't want to accept any answers to your questions.

I'm really at a loss here. I don't understand how the last couple of comments are warranted.
I'm at a loss as to what comments you're referring to.

I never said one way is better than the other.
A lot of other people have said it quite clearly that a single pack is technically better for safety and battery longevity. It's not my fault you don't want to accept that fact.

I asked a simple question of opinion, would a comparing test be something that other than myself would be interested in seeing. I would think anyone weighing the pros and cons if they should get dual or single batteries would appreciate the information. Instead of an answer there is a repeat of a single battery is better than dual series batteries. Again how does any of this relate to answering?
If you understood the basic laws of electricity and electrical principles, we wouldn't be having this conversation. You would understand why it's a potential concern, why people do it anyway, how to mitigate the side effects of running in series as much as possible, and why there's no need for any such tests that you supposedly keep asking about. If you want to do some testing, by all means do some testing, but stop coming back to this thread arguing about what are widely accepted facts. The only reason you keep going on about testing is that you think if someone does some testing, that your original hypothesis will be vindicated. If you're not willing to learn how to do the testing and actually do the testing, then you might want to start just trusting what everyone is telling you. Otherwise, do the testing in a thorough and accurate manner and prove everyone else wrong.

You keep saying that you've repeatedly asked the same question but let's look at that for a moment.

The first question in the thread you asked was: "The part I don't understand is that a single large battery has the same cells as a same voltage multi battery in series pack.". I answered this question.

The second question you asked was: "If you take away having poor connectors what is so bad?" I answered this question.

The third question you asked was: "Has there ever been a study showing how one setup is much better than the other? How much sooner do/can they die?" Ok, maybe I was a little unclear about answering this question. Yes they die sooner, how much sooner you'd have to record some data and do that actual math because no one else can do that for you since the answer depends on your specific data, and you don't need a study to show the differences, it's a simple matter of doing the math. That however requires you to understand the laws and principles behind it in order to do these types of formulations. This became obvious when I said that if you ran some tests and collected the voltage levels and IR levels of some packs, you could see the differences. You didn't bother to look at anything besides voltage levels, and you did so after only one run. Testing is a series of controlled tests that looks at all the factors involved over multiple data sets. Now, I will admit I did make the statement "There will be a fairly significant difference from one pack to the other pack." which may have been a bit confusing because I didn't clarify that I was referring to a pair of batteries that had many cycles on them from many complete rounds of testing. Relatively new batteries are not going to have enough degradation on them to be a lot different in the beginning. Plus, the higher quality the cells, the longer it will take them to degrade. Do not confuse this as "there are no safety or longevity concerns" though because that would be short-sighted.

The fourth question you asked was: "wouldn't be nice to actually know what to expect in the difference in life expectancy." I gave you a formula to help you try and calculate the degradation, but you dismissed it by saying, "The second half reads as to how some factors for a test should be recorded. Those same factors should be used when testing any battery.". Use the formula or don't, it doesn't matter to me.

Additionally, You've made the claim once or twice that you keep asking the same question, but if you look back at all your responses, its quite clear that you never once repeated the same question twice. You did mention testing multiple times, but never referenced it in the same way twice or asked the same specific question twice. It's quite clear that you are either so deeply confused about this topic that you can't articulate what you're trying to ask, or you just want to be argumentative. Either way, I'm done discussing this topic with you. I can lead a horse to water, but I can't make him drink.
 
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Basically, running dual packs is fine, but running a single pack is better. Matched pairs of batteries will be the ideal setup in a dual battery configuration. Everyone knows this. If you want to prove it or disprove it, do some testing. And no, I don't see the battery manufacturer providing this kind of data being at all helpful, because it would not be relevant to your particular situation. Your rig will not be putting the same loads on the battery as their test setup. Stop beating a dead horse.
 
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Basically, running dual packs is fine, but running a single pack is better. Matched pairs of batteries will be the ideal setup in a dual battery configuration. Everyone knows this. If you want to prove it or disprove it, do some testing. And no, I don't see the battery manufacturer providing this kind of data being at all helpful, because it would not be relevant to your particular situation. Your rig will not be putting the same loads on the battery as their test setup. Stop beating a dead horse.
Thank you for giving your opinion and answer to are there any kind of comparisons that have been done. And because you don't think there is any I would need to do my own comparisons.
I asked the same question different ways because there was no answer given. Post #14 Has there been a comparison, Post #18 Are you dismissing my idea of a test, Post #21 & #23 wouldn't it be nice if there was some type of comparison. Why call it beating a dead horse if the only answer given was yours above?


@Greywolf74
Up until were I showed you my batteries matched which negated your comment about significant differences that would be seen your comments changed when I mentioned how the SMC article is pointed to (or referenced). I made a simple comment about how running series configuration is frowned upon. (That's what the SMC article is about). You came out and said it is not. Then you start writing about testing and the hazards associated with anything in a series configuration. This contradicts your not frowned upon comment. They only thing you kept mentioning is how to and what factors for a test which neither answer any of my reworded questions. "Additionally, You've made the claim once or twice that you keep asking the same question, but if you look back at all your responses, its quite clear that you never once repeated the same question twice. You did mention testing multiple times, but never referenced it in the same way twice or asked the same specific question twice." In nearly each of my comments I did mention is there or wouldn't it be nice if there was a comparison done. Not sure how to more specific when I only asked is there ANY type of comparison. I never asked for any how-to.

Your comments come across as you wanted to somehow disprove my experience with running dual batteries. Since you mentioned widely accepted facts the simple question I asked was do you have any links besides SMC's article in a very courteous way on bottom of Post #18. You only picked and choose what questions to answer in each post. I debated your response to a question and because I didn't get an answer to what I also asked I repeated only to be told I'm argumentative.

BTW: Why did your post #10 become edited after my reply #11 to your comments?
 
I asked the same question different ways because there was no answer given. Post #14 Has there been a comparison, Post #18 Are you dismissing my idea of a test, Post #21 & #23 wouldn't it be nice if there was some type of comparison.
I purposely avoided answering that specific question directly because I knew it wouldn't do any good. You don't think SMC has done their own internal testing? (The SMC article even talks about some of the testing they do, btw) You don't think their engineers know what they are talking about? When a well respected LiPo company gives me battery info, I just tend to trust that they know what they are talking about. I suppose that's easier to do when you have a good grasp of the science behind it in the first place. The fact that you are arguing with the whole premise makes me realize that there's no convincing you of anything, so why bother?

Additionally, I did actually try and answer this in a round about way by explaining the science and the math involved in figuring out all the details. If you understand this, you understand that there's no need for testing.

P.S. Post #18 poses a question about the question in post #14 and does really constitute "the same question". You are asking me in #18 why I didn't answer the question from post #14 which is not the same as re-asking the question in my mind, but I'm not going to argue semantics with you.

Post #21 does not pose any question about testing, only a statement that it would be nice to have some tests. Not sure how I'm supposed to know that you want a response to a statement.

Post #23 asks a related but different question about "whether it would be interesting info to have". If you were trying to ask the same question, then I would suggest in the future you articulate that better so people who are trying to answer your questions understand that you are asking the same question.

@Greywolf74
Up until were I showed you my batteries matched which negated your comment about significant differences that would be seen your comments changed when I mentioned how the SMC article is pointed to (or referenced).
I'm not 100% sure what you're getting at here as your sentence is muddled, but if I understand what you're trying to say then my reply is that I avoided arguing with you about your supposed "test" because it's in no way shape or form a proper test. I already explained this to you earlier, so I'm not sure why you are bringing it up again as if I did not already address this.

I made a simple comment about how running series configuration is frowned upon. (That's what the SMC article is about). You came out and said it is not. Then you start writing about testing and the hazards associated with anything in a series configuration. This contradicts your not frowned upon comment.
No, it doesn't contradict my previous statement. The article is an informational piece about the downsides to running two packs in series and how to try and avoid those pitfalls as much as possible. Nowhere in that article does SMC tell people not to run two packs in a series, or even that they shouldn't do it. I'm not sure why you can't comprehend that.

They only thing you kept mentioning is how to and what factors for a test which neither answer any of my reworded questions. "Additionally, You've made the claim once or twice that you keep asking the same question, but if you look back at all your responses, its quite clear that you never once repeated the same question twice. You did mention testing multiple times, but never referenced it in the same way twice or asked the same specific question twice." In nearly each of my comments I did mention is there or wouldn't it be nice if there was a comparison done. Not sure how to more specific when I only asked is there ANY type of comparison. I never asked for any how-to.
You can lump this in with my learn to English response above.

Your comments come across as you wanted to somehow disprove my experience with running dual batteries.
I never said that. I can't help what you choose to infer from my responses.

Since you mentioned widely accepted facts the simple question I asked was do you have any links besides SMC's article in a very courteous way on bottom of Post #18.
I don't need other articles. Furthermore, I don't even need SMCs article because I understand the principles and the math involved. The article is for the benefit of people that are not educated in electrical properties and/or math.

You only picked and choose what questions to answer in each post.
I'm sorry, I wasn't aware that I was obligated to answer each and every question you post to your satisfaction. Please forgive me your majesty 🙄

I debated your response to a question and because I didn't get an answer to what I also asked I repeated only to be told I'm argumentative.
You were told that you were being argumentative because your question was answered several times, either directly or indirectly, but each time you came back trying to argue about the answer you were given. Most likely because you didn't understand the answers you were given. Again, all I can do is put info out there, I can't make people understand it.

BTW: Why did your post #10 become edited after my reply #11 to your comments?
I have over 16k posts in this forum. You really expect me to remember why I edited a post 5 days ago? I'm not sure what relevance that even has on this conversation other than you look bad in this thread, so you're grasping at straws trying to latch on to anything that may show some hint of impropriety on my part. Most likely, I saw some sort of grammatical error I wanted to correct, but who knows, I've slept since then.
 
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Thank you for giving your opinion and answer to are there any kind of comparisons that have been done. And because you don't think there is any I would need to do my own comparisons.
I asked the same question different ways because there was no answer given. Post #14 Has there been a comparison, Post #18 Are you dismissing my idea of a test, Post #21 & #23 wouldn't it be nice if there was some type of comparison. Why call it beating a dead horse if the only answer given was yours above?
Sorry, it has just felt like this thread turned into an arguement that was just going round and round. I felt the answers were given. Maybe they weren't understood. But the fact is people have been running dual battery setups for years. Part of using and caring for LiPo batteries is monitoring the health of them by looking at the voltages, mAh used, and internal resistances. If doing this properly you would see what running batteries in pairs is doing to your packs. After a run you will notice a difference in performance. It's not the end of the world to do so. But you will notice a difference over time. It is not "frowned upon" to run dual batteries. But anyone that understands LiPo care will know it's not as good as running a single pack.
 
Sorry, it has just felt like this thread turned into an arguement that was just going round and round. I felt the answers were given. Maybe they weren't understood. But the fact is people have been running dual battery setups for years. Part of using and caring for LiPo batteries is monitoring the health of them by looking at the voltages, mAh used, and internal resistances. If doing this properly you would see what running batteries in pairs is doing to your packs. After a run you will notice a difference in performance. It's not the end of the world to do so. But you will notice a difference over time. It is not "frowned upon" to run dual batteries. But anyone that understands LiPo care will know it's not as good as running a single pack.
Thanks. That's how conversations should be. Respectful :thumbs-up:






What I don't appreciate is this type of mentality when asking a question. Why does it matter what you want? Someone isn't allowed to read or get information from somewhere other than you? Sorry you felt the need to tell me what I need instead of what I asked.
Since you mentioned widely accepted facts the simple question I asked was do you have any links besides SMC's article in a very courteous way on bottom of Post #18.
I don't need other articles. Furthermore, I don't even need SMCs article because I understand the principles and the math involved. The article is for the benefit of people that are not educated in electrical properties and/or math.
Many of your replies are condescending and promote retaliatory type of responses. A recent perfect example of this, in a different thread someone asked for help finding a diagram. Your very first words are "Not trying to be a jerk but". How was that attitude warranted?
 
Thanks. That's how conversations should be. Respectful :thumbs-up:






What I don't appreciate is this type of mentality when asking a question. Why does it matter what you want?
it doesn't matter what i want just like it doesn't matter that you wanted me to answer all of your questions to your satisfaction. That was my whole point.

Many of your replies are condescending and promote retaliatory type of responses. A recent perfect example of this, in a different thread someone asked for help finding a diagram. Your very first words are "Not trying to be a jerk but". How was that attitude warranted?
You mean the mentality that I wanted to clarify that I wasn't trying to be a jerk but wanted to give the poster some basic information in case they were unaware and then went on to help them? I'd say it's warranted because I'm spending my time to help educate others and want them to understand that in many cases they can help themselves thus lightening the load on us regulars. If that suggestion makes them butthurt then I want them to know it wasn't my intention. What you call condensending I call "help me help you".
 
Many of your replies are condescending and promote retaliatory type of responses. A recent perfect example of this, in a different thread someone asked for help finding a diagram. Your very first words are "Not trying to be a jerk but". How was that attitude warranted?
Bringing this up in this thread is disrespectful to the OP and just shows you are in here to argue. Let it go. Your questions have been addressed.
 
I was waiting for discussion of using two 2S1P packs in a series vs. using two 2S2P packs in a series, but the subject never came into the fold.

I've read lots, and lots of LiPo threads over the years, and the subject matter gets my 1st place award for most heated topic ever. Good stuff. I'm sure someone reading this thread can take away some good info.
 
I was waiting for discussion of using two 2S1P packs in a series vs. using two 2S2P packs in a series, but the subject never came into the fold.

I've read lots, and lots of LiPo threads over the years, and the subject matter gets my 1st place award for most heated topic ever. Good stuff. I'm sure someone reading this thread can take away some good info.
The 2S2P packs run in series are going to have twice as many cells as two 2S1P packs, so there will be greater resistance overall. How much more? Is it enough to matter? I couldn't tell ya without doing a deep dive in to that subject and doing the math, which unfortunately, I'm not prepared to do just for the sake of curiosity. :)
I'm not a battery engineer but if I had to take an educated guess at it, I'd say it's probably not going to impact things much more than a pair of 2S1P packs will, and you'd just want to pay a little closer attention to making sure that you're doing everything possible to mitigate the downsides to running two packs in series.
 
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