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Thread: How often do you balance charge your lipo's?

  1. #11
    KC8UD GLEvideo's Avatar
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    I don't see how you can actually balance multiple cells together in parallel. The charger is needing to analyze each cell individually. There's no way it can do that with multiple cells connected in parallel. It seems to me that this isn't a true balance charge.
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  2. #12
    Think of it like this:

    Each cell in each pack is like a separate glass of water. When you connect packs in parrallel it is like connecting pipes in between each glass so that, say all of the second cells are connected together (imagine all of the glasses of water that represent the second cells being linked together by pipes). When they are plugged into the charging board initially each cell of the same number levels out so it has the same charge in, as if it is like water flowing between each glass so that they are all the same height. Then the balance charger concentrates on balancing each group of cells, say, Cell2 cells as if it is a single cell. End result all charged as if it is a single battery. In practice it is not quite as good as balancing each inidividual battery on its own, but is suprisingly good.


    Quote Originally Posted by GLEvideo View Post
    I don't see how you can actually balance multiple cells together in parallel. The charger is needing to analyze each cell individually. There's no way it can do that with multiple cells connected in parallel. It seems to me that this isn't a true balance charge.

  3. #13
    KC8UD GLEvideo's Avatar
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    I understand the theory of it but it seems this can only work if all of your cells are in perfect health. If you have one bad cell in the mix, the charger will continuously try to bring that cell up to normal voltage. In doing so, it will continue to bombard the other healthy cells that are in parallel with the bad one and could possibly damage them by overcharging. I think you would be on the safer side if you connect each battery, one at a time to the charger to run a quick analysis on each cell before connecting several batteries together for a balance charge. Eliminate any battery with a suspected bad cell from the mix and charge it separately. Just my thoughts. Am I being too conservative?
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  4. #14

    You Tube talk

    Most of the You Tube videos on chargers and charging say in mine to balance charge around every 4 or 5th time.

  5. #15
    Pilot Hockeystud87's Avatar
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    Quote Originally Posted by GLEvideo View Post
    I understand the theory of it but it seems this can only work if all of your cells are in perfect health. If you have one bad cell in the mix, the charger will continuously try to bring that cell up to normal voltage. In doing so, it will continue to bombard the other healthy cells that are in parallel with the bad one and could possibly damage them by overcharging. I think you would be on the safer side if you connect each battery, one at a time to the charger to run a quick analysis on each cell before connecting several batteries together for a balance charge. Eliminate any battery with a suspected bad cell from the mix and charge it separately. Just my thoughts. Am I being too conservative?
    I'm with GLEvideo. These balance chargers that the batteries all in parallel being charged like this will not "appropriately" charge the batteries to full health. We have to understand that the charger does not see 2, 3, 4, 5, how ever many batteries you have attached to the board. For all intents and purposes it only sees one voltage and one amperage for the entire group of batteries, then how ever many cells the batteries that are plugged into it are, it only see's one voltage for each cell. It will essentially only take the average of those cells and charge from there. So if you have a battery at 4.2 and a battery at 3.8 I'm pretty sure it only thinks there is a 4.0V battery, which is why having unbalanced cells can be dangerous cause it provides incorrect voltage readings and can lead to over charge or under charge.

    Long story short, Derrick, the person that linked the earlier balance board was wrong in his statement and should have taken a little more time in looking into the product he was recommending, as it could have cause an issues or damaged something if incorrectly used.
    Last edited by Hockeystud87; 8th July 2014 at 01:44 AM.
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  6. #16
    Is working on 12 projects Sicarius's Avatar
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    Once a cell has a higher resistance, there is no practical need to balance charge it anymore because it will become unbalanced every time you discharge it. I use Turnigy chargers which do need the balance lead connected at all times and with every "normal" charge on my healthy batteries it gets all cells to 4.20 but the specific "balance" setting on them does nothing more than try to bring low cells back up, which it fails at due to the resistance.
    If the regular charge on the turnigy charger isn't balance, then I don't think it does anything for the batteries..
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  7. #17
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    How often do you balance charge your lipo's?

    A very large proportion of charge related lipo fires that I have read about have been charging on a non balance charge... In fact almost all of them. Considering that a single cell going over voltage can lead to a fire, and that charging without a balance lead connected means that the charger has no freaking idea what is going on on an individual cell basis, I think the only safe choice is to always balance charge.

    I'm not saying that if you don't balance charge all of a sudden your lipos will explode, but it significantly reduces a major safety feature of the charger by not using it. That doesn't make sense to me.

    Sicarius - what you are describing is a balance charge, a non balance charge doesn't have the balance leads connected and/or no monitoring of individual cells. The turnigy requiring the balance lead means they have been sensible and require monitoring of the cells at all times and as all your cells reach 4.20 you can see it's doing the job of balancing out as it charges... What you say regarding the lack of need to balance charge with a duff cell is risky - if you have a poor cell the need to balance charge is higher than ever. Imagine a typical 3S lipo, with no balance connected the charger will try to take it up to 12.6v as usual. If one if the cells is bad and can't get above eg 3.8v, then that means the charger will be overcharging the remaining two cells still trying to reach 12.6v as it has no idea that they have exceeded 4.2v - that right there is a disaster waiting to happen.
    Last edited by Zeeflyboy; 8th July 2014 at 06:26 AM.

  8. #18
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    How often do you balance charge your lipo's?

    Quote Originally Posted by GLEvideo View Post
    I understand the theory of it but it seems this can only work if all of your cells are in perfect health. If you have one bad cell in the mix, the charger will continuously try to bring that cell up to normal voltage. In doing so, it will continue to bombard the other healthy cells that are in parallel with the bad one and could possibly damage them by overcharging. I think you would be on the safer side if you connect each battery, one at a time to the charger to run a quick analysis on each cell before connecting several batteries together for a balance charge. Eliminate any battery with a suspected bad cell from the mix and charge it separately. Just my thoughts. Am I being too conservative?
    Certainly there is nothing wrong with what you suggest doing, but parallel balance charging is perfectly safe really. You can't overcharge the good cells as they are all connected in parallel, not series. You simply can't have a 3.6v cell in parallel with a 4.2v cell (well, for a nanosecond you could when first connecting)... The voltage will equalise. Equally, if the charger is reading 4.2v on that bank of cells, none of those cells can be significantly above 4.2v and thus won't be being overcharged.... Now when you disconnect of course, the bad cell might not hold the charge and will go back to being the runt of the litter. It's also possible that the charger simply won't be able to bring that bank up above eg 4v, but the good cells won't be being overcharged.

    The one caveat with parallel charging is that it is a good idea to check your battery voltage (and indeed individual cells occasionally) to make sure they are in the same ball park when connecting together. Connecting a full battery and an empty one will result in an uncontrolled charging of the lower cells by the higher cells and is potentially bad for battery health. They don't need to be identical but within the same rough range is a good idea.


    Quote Originally Posted by Hockeystud87 View Post
    I'm with GLEvideo. These balance chargers that the batteries all in parallel being charged like this will not "appropriately" charge the batteries to full health. We have to understand that the charger does not see 2, 3, 4, 5, how ever many batteries you have attached to the board. For all intents and purposes it only sees one voltage and one amperage for the entire group of batteries, then how ever many cells the batteries that are plugged into it are, it only see's one voltage for each cell. It will essentially only take the average of those cells and charge from there. So if you have a battery at 4.2 and a battery at 3.8 I'm pretty sure it only thinks there is a 4.0V battery, which is why having unbalanced cells can be dangerous cause it provides incorrect voltage readings and can lead to over charge or under charge.

    Long story short, Derrick, the person that linked the earlier balance board was wrong in his statement and should have taken a little more time in looking into the product he was recommending, as it could have cause an issues or damaged something if incorrectly used.
    Incorrect - the cells cannot exist at 3.8 and 4.2 in parallel... The higher cell will charge the lower cell, on connection the linked cells will all automatically roughly balance each other out, even if that voltage can't then be sustained after disconnection.

    Were you charging them in series, yes you could see a total voltage of 8v (thus average of 4v) and have one at 3.8 and one at 4.2 - this is actually the reason why balance charging is so important. If you are not balance charging then all you are doing is ending up with a series charge and this the exact problem that can happen - total pack voltage correct at eg 12.6v, but cells at 4.2, 4.0 and 4.4 - fire risk.


    There is nothing wrong with parallel charge boards as linked. Cell pro make some very nice ones with fused connections too, but they are a bit spendy.
    Last edited by Zeeflyboy; 8th July 2014 at 06:27 AM.

  9. #19
    I see you... Derrick's Avatar
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    Quote Originally Posted by Hockeystud87 View Post
    I'm with GLEvideo. These balance chargers that the batteries all in parallel being charged like this will not "appropriately" charge the batteries to full health. We have to understand that the charger does not see 2, 3, 4, 5, how ever many batteries you have attached to the board. For all intents and purposes it only sees one voltage and one amperage for the entire group of batteries, then how ever many cells the batteries that are plugged into it are, it only see's one voltage for each cell. It will essentially only take the average of those cells and charge from there. So if you have a battery at 4.2 and a battery at 3.8 I'm pretty sure it only thinks there is a 4.0V battery, which is why having unbalanced cells can be dangerous cause it provides incorrect voltage readings and can lead to over charge or under charge.

    Long story short, Derrick, the person that linked the earlier balance board was wrong in his statement and should have taken a little more time in looking into the product he was recommending, as it could have cause an issues or damaged something if incorrectly used.
    It is basic physics... well, perhaps Physics III Electricity and Magnetism. Electricity always flows from source to sink, thus you can't have one battery at 4.2 and another at 3.8, it is not physically possible unless you are looking at the voltage over the very instant that the packs are plugged into the parallel board.
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  10. #20
    Is working on 12 projects Sicarius's Avatar
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    I'm pretty sure hooking a low cell to a full cell will result in less desirable situations.. They will equalize by rapidly flowing the energy from the full to the low cell. There's a reason why we charge at 1 or 2c..
    Zee: i had my suspicion, glad they built in that safety. Never had the experience with a charger that works without a balance lead.
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