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Thread: Looking for maintenance and care advice for Lithium ion battery pack

  1. #1

    Default Looking for maintenance and care advice for Lithium ion battery pack

    I recently got a phantom drone for Christmas, and was wondering if the same rules for care and maintenance apply for a battery pack as it does for single cells? The specs of the battery are below:




    • Voltage of 15.2 Volts (4) 3.8v cells inside pack
    • Max Charging Power – 100W
    • Net Weight – 462 G
    • Energy Level – 81.3 Wh
    • Capacity of 5350 mAh.
    • Operating Temperature of 14 degrees to 104 degrees Fahrenheit (-10 to 40 celsius)
    • Battery Type – Lithium Ion Polymer LiPo 4S


    My main questions are:

    Is it OK to drain down to 20% capacity left during each use? I've read that you should never go below 80% discharge for max overall battery life. Is that right, or should that number be lower?

    I know for long term storage it is a good idea to store at 50%, but if I will be using them at least every week or two, would I be better off keeping them stored fully charged?

    Lastly, is it a good idea to do a full discharge every few months or so?

    Thanks in advance for any advice you can give!
    Last edited by ifoxbox; 02-19-2017 at 07:22 PM.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Hello Ifoxbox,

    I think the 20% left is a good target to shoot for.

    Long term storage is usually longer than 1 week. If it is not too much trouble it is better to store at 50% and charge prior to use. If that is not convenient just charge them and use them.

    No full discharge is necessary or recommended.

    Tom
    Behind every Great man there's always a woman rolling her eyes...

    Most batteries don't die - they are tortured to near death, then murdered...

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    Flashaholic olemil's Avatar
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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    LiPo packs like to be stored at 3.85v per cell.
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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by SilverFox View Post
    Hello Ifoxbox,

    I think the 20% left is a good target to shoot for.

    Long term storage is usually longer than 1 week. If it is not too much trouble it is better to store at 50% and charge prior to use. If that is not convenient just charge them and use them.

    No full discharge is necessary or recommended.

    Tom
    Thanks Tom! I was hoping you would chime in. I always value your input!

    So after I drain the battery down to 20%, I should just charge it back up to 50% and then finish the charge the next week before I plan to use it again?



    Quote Originally Posted by olemil View Post
    LiPo packs like to be stored at 3.85v per cell.
    Thanks for the info!

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Based on numerous studies, the general rule of thumb for Li-ion batteries is: to maximize life, minimize the time that the battery spends at extreme voltages and high temperatures (which accelerate internal processes that cause degradation). For example, one of the worst things you could do is to keep your cells floating at 100% SOC on standby charge (or frequent top-ups), since this means that the cells will spend most of their life at the highest extreme voltage. Better to design a charging regimen that maximizes the time they spend near 50% capacity (e.g. store at 50% then top-up as close to use as is practical).

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by olemil View Post
    LiPo packs like to be stored at 3.85v per cell.
    That is too high SOC (70%) for storing some common chemistries. The optimal storage range is between 40-50% SOC. To determine the corresponding resting voltages see e.g. HKJ's page for a few common chemistries.

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    Default Looking for maintenance and care advice for Lithium ion battery pack

    I think a voltmeter would be in order but since you have a battery pack not sure how you would measure it and even if you can what would the optimal voltage be, since they are in series, as I understand. Hoping that each battery has the same discharge rate but if they don't and have say a 20% difference that is too much of a difference between the batteries in the pack. The 18650 I have I measure each one individually, the lights I have only take 1x18650.
    Last edited by marinemaster; 02-20-2017 at 08:59 PM.

  8. #8

    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by Gauss163 View Post
    That is too high SOC (70%) for storing some common chemistries. The optimal storage range is between 40-50% SOC. To determine the corresponding resting voltages see e.g. HKJ's page for a few common chemistries.
    Lipo charges have a storage setting which charges them to 3.85v and this is the widely accepted voltage for long term storage.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by novarider View Post
    Lipo charges have a storage setting which charges them to 3.85v and this is the widely accepted voltage for long term storage.
    Look at datasheets, etc. and you will learn that cell manufacturer's recommend storing at between 40-50% SOC (and that's what they are typically shipped at). The voltages corresponding to 40-50% SOC depend on the chemistry.

    For many chemistries (esp. older ones) 3.85V is about 55% SOC, but for many newer chemistries it is much higher - about 70%, whereas 50% is about 3.65V. Hobby chargers cannot determine the chemistry so if they have a fixed storage voltage target value then that has to be a compromise value that suffices for most chemistries. e.g. they cannot choose 3.65V since that is only about 6% SOC for older chemistries. If you want optimal storage values you need a charger with programmable storage charging (or a general CC/CV charger).

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    To the OP: You might want to have a look here, lots of valuable info on Lipo packs including safety tips. Also there are many threads on Multi-rotors so you can probably pick a few tips on your Phantom. Not sure where you are located but if you are in the US, you are supposed to register with the FAA to make it legal to fly.
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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by Gauss163 View Post
    Look at datasheets, etc. and you will learn that cell manufacturer's recommend storing at between 40-50% SOC (and that's what they are typically shipped at). The voltages corresponding to 40-50% SOC depend on the chemistry.

    For many chemistries (esp. older ones) 3.85V is about 55% SOC, but for many newer chemistries it is much higher - about 70%, whereas 50% is about 3.65V. Hobby chargers cannot determine the chemistry so if they have a fixed storage voltage target value then that has to be a compromise value that suffices for most chemistries. e.g. they cannot choose 3.65V since that is only about 6% SOC for older chemistries. If you want optimal storage values you need a charger with programmable storage charging (or a general CC/CV charger).
    Funny I have about $1000 worth of LiPo packs for my RC hobby. Every pack I have ever bought (NEW) shipped at a storage voltage of 3.85v/cell. Must be a lot of LiPo battery companies that don't know what the hell they are doing. All the hobby chargers I have owned over the years have an adjustable storage voltage setting ( for various battery chemistries ) including my current one, ICharger 308 DUO. PS, the default storage voltage for LiPo batteries is 3.85v/cell.

    LiPo settings Taken from my 308 DUO manual:

    Storage Cell Voltage:
    3.7V/Cell-3.9V/Cell;
    Default: 3.85V/Cell
    Storage Compensation:
    0V/Cell-0.2V/Cell;
    Default: 0.01V/Cell
    Last edited by olemil; 02-21-2017 at 03:39 PM.
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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by olemil View Post
    Funny I have about $1000 worth of LiPo packs for my RC hobby. Every pack I have ever bought (NEW) shipped at a storage voltage of 3.85v/cell. [...]
    Again, optimal storage voltage depends on the particular Li-ion chemistry of the cells. Probably your LiPo pack recommendations are based on the fact that most of the chemistries used in the RC/hobby packs were/are close to 50% SOC around 3.85V. But that is not true for many other common modern Li-ion chemistries, where 50% SOC is about 3.65V. For example, this is true for all of the 18650 cells except the first two in HKJ's SOC vs Voltage page. This includes many common cells used in flashlights, vaping, powerbanks, laptops, etc (Panasonic CGRs and NCRs)

    For example, below is a table from said page. Notice that the first two columns shows chemistries like your LiPo, where 50% SOC occurs between 3.8-3.9V, but the final three columns shows cells where 50% SOC occurs between 3.6-3.7V.

    Last edited by Gauss163; 02-21-2017 at 05:03 PM.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Which Phantom do you have? White DJI battery? My Phantom 2 flashes red lights and lands itself when down to about 20%. And yes charging back to about 50% and fully charging the night before use would be the best way to store them. No benefit in running them down every few months etc.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by Gauss163 View Post
    Again, optimal storage voltage depends on the particular Li-ion chemistry of the cells. Probably your LiPo pack recommendations are based on the fact that most of the chemistries used in the RC/hobby packs were/are close to 50% SOC around 3.85V. But that is not true for many other common modern Li-ion chemistries, where 50% SOC is about 3.65V. For example, this is true for all of the 18650 cells except the first two in HKJ's SOC vs Voltage page. This includes many common cells used in flashlights, vaping, powerbanks, laptops, etc (Panasonic CGRs and NCRs)
    Ok
    Last edited by olemil; 02-21-2017 at 04:58 PM.
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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by PapaLumen View Post
    Which Phantom do you have? White DJI battery? My Phantom 2 flashes red lights and lands itself when down to about 20%. And yes charging back to about 50% and fully charging the night before use would be the best way to store them. No benefit in running them down every few months etc.
    Yes, it is the white DJI battery. Mine has an option to choose when to give the low battery warning. I have it set to 30%, and monitor it from there to be sure I land at 20%. I will charge back up to 50% later that day and then do a full charge before the next use.

    Thanks everyone for all the help!

  16. #16

    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by Gauss163 View Post
    Again, optimal storage voltage depends on the particular Li-ion chemistry of the cells. Probably your LiPo pack recommendations are based on the fact that most of the chemistries used in the RC/hobby packs were/are close to 50% SOC around 3.85V. But that is not true for many other common modern Li-ion chemistries, where 50% SOC is about 3.65V. For example, this is true for all of the 18650 cells except the first two in HKJ's SOC vs Voltage page. This includes many common cells used in flashlights, vaping, powerbanks, laptops, etc (Panasonic CGRs and NCRs)

    For example, below is a table from said page. Notice that the first two columns shows chemistries like your LiPo, where 50% SOC occurs between 3.8-3.9V, but the final three columns shows cells where 50% SOC occurs between 3.6-3.7V.

    Your trying to prove your right on a subject he didn't even ask about. He's asking about his lipo pack not 18650 batteries.

    There are millions of lipo packs sold and they all are shipped at 3.85v. The recommended storage charge is 3.85v.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by novarider View Post
    Your trying to prove your right on a subject he didn't even ask about. He's asking about his lipo pack not 18650 batteries.

    There are millions of lipo packs sold and they all are shipped at 3.85v. The recommended storage charge is 3.85v.
    Thank you.
    Last edited by olemil; 02-23-2017 at 04:26 AM.
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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by novarider View Post
    Your trying to prove your right on a subject he didn't even ask about. He's asking about his lipo pack not 18650 batteries.
    There are millions of lipo packs sold and they all are shipped at 3.85v. The recommended storage charge is 3.85v.
    Not true. I supplied the industry standard optimal storage targets, typically 35-50% SOC (depending on storage time, ambient temperature).

    Be aware that a lot of info in the RC/hobby world is outdated, e.g. many RC chargers use cloned firmware that still has the ancient distinction between Li-ion(3.6/4.1) vs LiPo(3.7/4.2).

    Even for higher voltages chemistries typically used in RC packs (where 3.85V is about 55% S0C), this is not the storage SOC that is optimal for prolonging life. Rather, optimal storage SOC is typically between 35-50% SOC (about 3.77-3.82V). For example, if you look at the datasheet for Sanyo/Panasonic NCR18650BE you will see that they are shipped at 35% SOC, i.e. slightly over one-third capacity.
    Last edited by Gauss163; 02-23-2017 at 10:37 AM.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    ifoxbox, please do yourself a favor and go to the site I posted in post #10, there is a vast amount of hands on knowledge there on LiPo packs. LiPo packs are not something to misuse, if you don't believe me do a search on YouTube for LiPo fires. Hope you are enjoying your Phantom, I have a DJI F450 and love it.
    Last edited by olemil; 02-23-2017 at 03:41 PM.
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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by olemil View Post
    I feel bad paying $280 for my charger now knowing it has outdated/ancient firmware......NOT!!!!!!! It's funny my charger has several types of battery chemistries to choose from for charging, discharging, storage charge and they all have different voltages depending which chemistry you choose.
    Which has nothing to do with what I wrote.

    I've owned over 30 RC/hobby charger models, ranging from earliest models (Bantam, Victor, etc) to more recent models (iChargers, Hyperions, etc). In my opinion, there has been very little innovation since the early days (primarily because of rampant cloning).

    You won't learn much about battery electrochemistry from hobby charger manuals. The hobby charger engineers are electrical engineers - not experts in battery electrochemistry. If you want to learn about finer points of battery electrochemistry you should look elsewhere.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by Gauss163 View Post
    Not true. I supplied the industry standard optimal storage targets, typically 35-50% SOC (depending on storage time, ambient temperature).

    Be aware that a lot of info in the RC/hobby world is outdated, e.g. many RC chargers use cloned firmware that still has the ancient distinction between Li-ion(3.6/4.1) vs LiPo(3.7/4.2).

    Even for higher voltages chemistries typically used in RC packs (where 3.85V is about 55% S0C), this is not the storage SOC that is optimal for prolonging life. Rather, optimal storage SOC is typically between 35-50% SOC (about 3.77-3.82V). For example, if you look at the datasheet for Sanyo/Panasonic NCR18650BE you will see that they are shipped at 35% SOC, i.e. slightly over one-third capacity.
    Yes it is true you just did it again. Ncr18650b batteries are not what he was asking about. What your saying is that EVERY SINGLE lipo manufacturer including the highest quality and most respected companies are all wrong and your right. simply because you saw a data sheet for 18650 batteries which is not even what we're discussing.

    Do some searching for info on lipo batteries NOT 18650 and you will see they recommend 3.85v for storage. This comes from the battery manufacturer.

    A quick Google search for lipo battery care and this is from the first link: For the longest life of the batteries, LiPos should be stored at room temperature at 3.8V per cell.

    Scroll down to the 3rd result and you get this
    Maxamps website says: Storage Procedure: When not using your LiPo/Life battery pack, store it at 60-70% of the pack’s rated capacity.

    There are many more if you care to look.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by novarider View Post
    Lipo charges have a storage setting which charges them to 3.85v and this is the widely accepted voltage for long term storage.

    +1

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by Gauss163 View Post
    Look at datasheets, etc. and you will learn that cell manufacturer's recommend storing at between 40-50% SOC (and that's what they are typically shipped at). The voltages corresponding to 40-50% SOC depend on the chemistry.

    For many chemistries (esp. older ones) 3.85V is about 55% SOC, but for many newer chemistries it is much higher - about 70%, whereas 50% is about 3.65V. Hobby chargers cannot determine the chemistry so if they have a fixed storage voltage target value then that has to be a compromise value that suffices for most chemistries. e.g. they cannot choose 3.65V since that is only about 6% SOC for older chemistries. If you want optimal storage values you need a charger with programmable storage charging (or a general CC/CV charger).
    He is asking about Lithium Polymer Gauss, not other chemistries. 3.85V is what most, if not all, lipo manufactures recommend for storage.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by novarider View Post
    Yes it is true you just did it again. Ncr18650b batteries are not what he was asking about. What your saying is that EVERY SINGLE lipo manufacturer including the highest quality and most respected companies are all wrong and your right. simply because you saw a data sheet for 18650 batteries which is not even what we're discussing.

    Do some searching for info on lipo batteries NOT 18650 and you will see they recommend 3.85v for storage. This comes from the battery manufacturer.

    A quick Google search for lipo battery care and this is from the first link: For the longest life of the batteries, LiPos should be stored at room temperature at 3.8V per cell.

    Scroll down to the 3rd result and you get this
    Maxamps website says: Storage Procedure: When not using your LiPo/Life battery pack, store it at 60-70% of the pack’s rated capacity.

    There are many more if you care to look.
    +1, good post with accurate information.

    Gauss is a known trouble maker. He has been reprimanded and banned several times but, still causes trouble. I suggest you don't waste your time arguing with him
    Last edited by Tachead; 02-25-2017 at 10:09 AM.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by ifoxbox View Post
    I recently got a phantom drone for Christmas, and was wondering if the same rules for care and maintenance apply for a battery pack as it does for single cells? The specs of the battery are below:




    • Voltage of 15.2 Volts (4) 3.8v cells inside pack
    • Max Charging Power – 100W
    • Net Weight – 462 G
    • Energy Level – 81.3 Wh
    • Capacity of 5350 mAh.
    • Operating Temperature of 14 degrees to 104 degrees Fahrenheit (-10 to 40 celsius)
    • Battery Type – Lithium Ion Polymer LiPo 4S


    My main questions are:

    Is it OK to drain down to 20% capacity left during each use? I've read that you should never go below 80% discharge for max overall battery life. Is that right, or should that number be lower?

    I know for long term storage it is a good idea to store at 50%, but if I will be using them at least every week or two, would I be better off keeping them stored fully charged?

    Lastly, is it a good idea to do a full discharge every few months or so?

    Thanks in advance for any advice you can give!
    I recommend checking your packs resting voltage after you fly. You only want to drain your lipos to 3.7-3.75V per cell if you want the best life and performance out of them. Store them at 3.85V if you plan on not using them for more then a day or two. Most hobby chargers have a storage mode to do this automatically for you.

    Get yourself a simple tester like this one...

    http://media.hyperion.hk/dn/sentry/

    It will show you the voltage of each cell in your packs by plugging in the balance connector. That way you can monitor both the voltage and how well your charger is balancing the individual cells. A tester like this and a high quality charger is a must for every RC hobbyist imo.
    Last edited by Tachead; 02-25-2017 at 10:07 AM.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by Tachead View Post
    I recommend checking your packs resting voltage after you fly. You only want to drain your lipos to 3.7-3.75V per cell if you want the best life and performance out of them. Store them at 3.85V if you plan on not using them for more then a day or two. Most hobby chargers have a storage mode to do this automatically for you.

    Get yourself a simple tester like this one...

    http://media.hyperion.hk/dn/sentry/

    It will show you the voltage of each cell in your packs by plugging in the balance connector. That way you can monitor both the voltage and how well your charger is balancing the individual cells. A tester like this and a high quality charger is a must for every RC hobbyist imo.
    Great advice, thank you. I've had my EOS Sentry for years and love it, a must have for the money to monitor your packs easily.
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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by olemil View Post
    Great advice, thank you. I've had my EOS Sentry for years and love it, a must have for the money to monitor your packs easily.

    No problem. RC helicopters are one of my other hobbies and I have had my EOS Sentry and another tester for years as well. A high quality charger and a good tester are definitely essential to properly maintain your lipos and keep safe in the RC hobby. Lipo batteries can be very dangerous and even more care should be taken then with normal cylindrical lithium ions like 18650's.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    @Tachead Yet more unfounded ad hominem attacks are not the proper way to dispute scientific claims. As always, if anyone has any questions about any claims then please feel welcome to ask and I will provide further data to back up those claims (beyond HKJ's voltage vs SOC graphs above).

    A couple more points deserve mention regarding shipping/storage SOC. One of the reasons that rewrappers and other Li-ion battery resellers employ a very conservative shipping/storage charge around 55% SOC is due to the fact that these packs/cells may sit on the shelf in (possibly hot) warehouses for quite some time, so they use a more conservative (higher) shipping voltage charge to make sure they do no drain too low even if they do not sell for some time. It also makes sense to recommend more conservative storage values to users, so that they don't have to deal with warranty claims and/or complaints from users who forgot to recharge their batteries after leaving them in storage for too long (which often occurs).

    Note that the self-discharge rate depends on many factors, temperature, chemistry, BMS quiescent current , etc. Generic storage SOC recommendations (e.g. in a charger manual) have to account for all these variations, so are typically less optimal than recommendations that are specialized to specific chemistry and BMS, etc.

    Finally, it goes without saying that battery sellers make more money when batteries have shorter life, so they don't have a strong incentive to provide information that yields maximal lifetime. For example, Dell laptops once had a built-in timer that would wrongly claim that the batteries needed replacing - which led to a lawsuit; further they did not supply battery saver software until forced to do so by competition. Accessories like batteries are a huge source of profit for battery-powered devices, so manufacturers typically do the least possible when it comes to educating consumers about how to optimize calendar or cycle life.
    Last edited by Gauss163; 02-25-2017 at 10:55 AM.

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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by Tachead View Post
    No problem. RC helicopters are one of my other hobbies and I have had my EOS Sentry and another tester for years as well. A high quality charger and a good tester are definitely essential to properly maintain your lipos and keep safe in the RC hobby. Lipo batteries can be very dangerous and even more care should be taken then with normal cylindrical lithium ions like 18650's.
    Nice to see a fellow RC heli enthusiast on here. Yes LiPo fires are very scary to say the least!! I store mine in vented ammo cans which are stored in a large metal cabinet. Sorry to drift off topic.
    Nitecore SRT6, Nitecore TM26(with NBP52 battery), Xtar B20 Pilot, ThruNite TN32, Rofis TR51, Fenix TK35UE, Olight SR52, Klarus RS20, Nitecore EA41, Olight S1a, Klarus G20, Olight S2 copper.

  30. #30
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    Default Re: Looking for maintenance and care advice for Lithium ion battery pack

    Quote Originally Posted by Gauss163 View Post
    @Tachead Yet more unfounded ad hominem attacks are not the proper way to dispute scientific claims. As always, if anyone has any questions about any claims then please feel welcome to ask and I will provide further data to back up those claims (beyond HKJ's voltage vs SOC graphs above).

    A couple more points deserve mention regarding shipping/storage SOC. One of the reasons that rewrappers and other Li-ion battery resellers employ a shipping charge a bit higher than 50% SOC is due to the fact that these packs/cells may sit on the shelf in (possibly hot) warehouses for quite some time, so they use a more conservative (higher) shipping voltage charge to make sure they do no drain too low even if they do not sell for some time. It also makes sense to recommend more conservative storage values to users, so that they don't have to deal with warranty claims and/or complaints from users who forgot to recharge their batteries after leaving them in storage for too long (which often occurs).

    Also, depending on chemistry, there will be some variation in self-discharge rates (which are strongly dependent on ambient temperature), which play a (minor) role.

    Finally, it goes without saying that battery sellers make more money when batteries have shorter life, so they don't have a strong incentive to provide information that yields maximal lifetime. For example, Dell laptops once had a built-in timer that would wrongly claim that the batteries needed replacing - which led to a lawsuit; further they did not supply battery saver software until forced to do so by competition. Accessories like batteries are a huge source of profit for battery-powered devices, so manufacturers typically do the least possible when it comes to educating consumers about how to optimize calendar or cycle life.
    Gauss, as said, we are not talking about cylindrical lithium ions in this thread. We are talking about lithium polymer hobby packs. Therefore, HKJ's chart you posted does not apply here and is off topic. Most lithium polymer hobby pack manufacturers recommend 3.85V be used for storage. Most high end hobby chargers(not clones) also use this voltage for their storage modes. Your posts are off topic in this thread, are riddled with misinformation on this topic(Lipo hobby packs), and your disrupting yet another thread in the battery forum. Please stop posting about off topic subjects and derailing this thread.

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