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Thread: Charging Eneloops

  1. #1
    Flashaholic 2manybikes's Avatar
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    Default Charging Eneloops

    My Eneloop charger will only charge two or four cells at a time.

    If I put in an almost drained cell and one about 80% will each cell charge properly?
    If it overcharges one cell, is it better for the batteries to leave one cell almost empty untill I have two cells about the same, or is it better to overcharge one cell once in a while?

  2. #2

    Default Re: Charging Eneloops

    I'm a noob, but I think it depends on your charger. Some treat each cell independently, and some group the cells into blocks of 2-4 batteries and charge them all at once. If it treats them all independently, then you're of course alright. If it treats them as a series circuit, I'll let the experts answer that.

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    Flashaholic* LukeA's Avatar
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    Default Re: Charging Eneloops

    Then it sounds like a 2-channel charger. Can you put one cell on each channel?

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    Default Re: Charging Eneloops

    Hello 2manybikes,

    The best thing to do is to get a charger that is capable of charging single cells.

    With NiMh cells, you want to avoid overcharging as much as possible. It seems this is even more important with the low self discharge cells. You will have better results if your cells are at about the same level of discharge before trying to charge them.

    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 2manybikes's Avatar
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    Default Re: Charging Eneloops

    Quote Originally Posted by SilverFox View Post
    Hello 2manybikes,

    The best thing to do is to get a charger that is capable of charging single cells.

    With NiMh cells, you want to avoid overcharging as much as possible. It seems this is even more important with the low self discharge cells. You will have better results if your cells are at about the same level of discharge before trying to charge them.

    Tom
    Thanks.

    I managed to order a Q5, I hope it's not a non-updated web page. I found your thread about it from last year. Have you been using yours all this time?

    I only saw one place to get it. I wonder why they changed it? Probalby cost more, and most consumers don't see or understand the benefits.

  6. #6
    Flashaholic 2manybikes's Avatar
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    Default Re: Charging Eneloops

    They sent me a Q6, I already have one. What's a good chager for a single AA and AAA eneloops?

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    Flashaholic* Wattnot's Avatar
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    Default Re: Charging Eneloops

    An independant channel charger would be best but as long as your drained batteries are close to the same level of empty, you should be fine. If two batteries are required then it must be charging them in series in which case they should equalize and both receive the same charge. I could be wrong about that but I have many multiple cell packs (4 though 9 cell) that get charged in series and they work fine. However, they're discharged in series too so that's why I say try to drain them to the same level, if possible.

    Displacing night on a daily basis.

  8. #8

    Default Regarding Eneloops and Charger

    I know that these threads are rampant, but I wanted a personal response. I recently ordered a Romisen RC-N3 Q5 from shiningbeam.com. My first question is whether Eneloops are compatible with this flashlight (I presume yes), and secondly, does this battery/charger combo from amazon.com seem like a good deal? Thanks for any responses!

  9. #9
    *Flashaholic* Marduke's Avatar
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    Default Re: Regarding Eneloops and Charger

    Yes, and kinda. That charger only charges cells in pairs. You cannot charge a single cell by itself. A pair of cells charged must be close to the same state of discharge.

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    Flashaholic 2manybikes's Avatar
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    Default Re: Regarding Eneloops and Charger

    I already ordered a La Crosse Technology BC700 Alpha Power Battery Charger Where's the "Charger Collecting" forum ?

    Ever notice how an idea to save money and save energy slowly turns into a huge expensive project ? Oh wait....I forgot......this is "CandelPowerForums" that's what everone does. .

  11. #11

    Default Re: Charging Eneloops

    I just read a bunch of consumer grade literature by Sanyo, and while there were warnings just about anything, I didn't see any cautions about charging together cells that are in different states of discharge. So perhaps there is no issue here?

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    *Flashaholic* Marduke's Avatar
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    Default Re: Charging Eneloops

    Quote Originally Posted by pilou View Post
    I just read a bunch of consumer grade literature by Sanyo, and while there were warnings just about anything, I didn't see any cautions about charging together cells that are in different states of discharge. So perhaps there is no issue here?
    Depends on what charger you use to charge them with. Independent channel, no problem. But if it's not independent channel, you can cook the cell with the higher state of charge.

  13. #13

    Default Re: Charging Eneloops

    Quote Originally Posted by Marduke View Post
    Depends on what charger you use to charge them with. Independent channel, no problem. But if it's not independent channel, you can cook the cell with the higher state of charge.
    I am talking about the charger that currently comes with the Costco Eneloop package. It seems to have one channel per pair, so each battery doesn't have an independent channel. But there is no warning anywhere about charging pairs of batteries with different states of charge. But they warn about having to charge with the batteries upright

    I wonder whether there is no warning because there is no issue with disparate state of charge for charging the Eneloops. Do other brand chargers with non independent channels provide any type of warning or is this just one of those dirty little secrets that affects every NiMH system but that no manufacturer acknowledges?

    (edited for clarity)
    Last edited by pilou; 06-25-2008 at 04:49 PM.

  14. #14
    Flashaholic Aluminous's Avatar
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    Default Re: Charging Eneloops

    Quote Originally Posted by pilou View Post
    Do other brand chargers with non independent channels provide any type of warning or is this just one of those dirty little secrets that affects every NiMH system but that no manufacturer acknowledges?
    I don't know the answer, but the thought that comes to mind regarding this is that as long as the degradation is sufficiently gradual that users won't notice and just think it's normal, that would mean they'd have to replace the batteries sooner. Like those chewing-gum commercials (Stride?) say, they want you to come back for more sooner. I'd think the reason for non-indepdendent-channel chargers even existing at all is that they're cheaper to make, and if they have this convenient side-effect too, well.....

  15. #15
    *Flashaholic* Marduke's Avatar
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    Default Re: Charging Eneloops

    Most people don't even know what "NiMH" is, or a "channel", let alone matching states of discharge.

    All cells should be matched, but they aren't going to print a 20 page manual for every package of batteries and chargers they sell describing the nuances of charging and battery care.

  16. #16
    Flashaholic* N162E's Avatar
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    Default Re: Charging Eneloops

    Quote Originally Posted by Marduke View Post
    Depends on what charger you use to charge them with. Independent channel, no problem. But if it's not independent channel, you can cook the cell with the higher state of charge.
    I may be just a noob at this stuff but, it seems to me that if you put two unevenly charged cells on the same channel they will be parallel and equal out. Should not be a problem.
    Fred R. Elias Jr. N162E
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  17. #17

    Default Re: Charging Eneloops

    Quote Originally Posted by N162E View Post
    I may be just a noob at this stuff but, it seems to me that if you put two unevenly charged cells on the same channel they will be parallel and equal out. Should not be a problem.
    Like some animals, these batteries just don't know when to stop eating. They'll keep ingesting until their stomach blows up or they run out of food.

  18. #18
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    Default Re: Charging Eneloops

    Hello Fred,

    Unfortunately with NiMh or NiCd cells, that doesn't work. When you parallel them, the voltage will equalize, but the actual charge will not balance.

    This will work great with Li-Ion cells, but not with nickel chemistry.

    In addition, some of the chargers charge in series and not in parallel. Now we have a charger looking for an end of termination signal and one cell may give it, but it may be hidden by the other cell and missed by the charger. If it is a timed charge at a 0.1C charge rate, this is not a problem, but at higher charge rates, one of the cells will get overcharged and suffer some damage as a result.

    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...

  19. #19
    Flashaholic* N162E's Avatar
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    Default Re: Charging Eneloops

    Quote Originally Posted by lowatts View Post
    Like some animals, these batteries just don't know when to stop eating. They'll keep ingesting until their stomach blows up or they run out of food.
    Just what I love. Worthless nonsensical information taking up space.
    Fred R. Elias Jr. N162E
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  20. #20
    Flashaholic* N162E's Avatar
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    Default Re: Charging Eneloops

    Quote Originally Posted by SilverFox View Post
    Hello Fred,

    Unfortunately with NiMh or NiCd cells, that doesn't work. When you parallel them, the voltage will equalize, but the actual charge will not balance.

    This will work great with Li-Ion cells, but not with nickel chemistry.

    In addition, some of the chargers charge in series and not in parallel. Now we have a charger looking for an end of termination signal and one cell may give it, but it may be hidden by the other cell and missed by the charger. If it is a timed charge at a 0.1C charge rate, this is not a problem, but at higher charge rates, one of the cells will get overcharged and suffer some damage as a result.

    Tom
    Thank you Tom. Great info, this is the type of response we need.
    Fred R. Elias Jr. N162E
    1-586-755-1245 24/7
    fre@felias.com

  21. #21

    Default Re: Charging Eneloops

    Quote Originally Posted by SilverFox View Post
    Now we have a charger looking for an end of termination signal and one cell may give it, but it may be hidden by the other cell and missed by the charger. If it is a timed charge at a 0.1C charge rate, this is not a problem, but at higher charge rates, one of the cells will get overcharged and suffer some damage as a result.
    The standard charger that comes with the Costco and other packages is a fairly slow charger. I think the provided time estimate for charge charging is be between 7-8 hours (can someone confirm?). Is that slow enough no to be a concern?

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