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  1. #1
    mtbr member
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    leave batteries plugged into charger ?

    so i noticed that after a weekend ( i don't ride at night on the weekend due to drunk drivers ) when i plug the batteries into the charger they will charge ( red led ) for some time ( maybe 15 minutes ) before the led goes green.

    and i know my kindle will go completely flat if i don't use it for a month or two.

    in other words lithium batteries self-discharge at a fairly significant rate.

    the protocol i'm using right now is i will charge the batteries to full immediately after i finish my ride, and then i will charge them again a second time to full just before a ride ( assuming i haven't been riding for more than a day or so )

    but it would be a lot easier for me to simply leave the batteries plugged into the chargers all the time. so if i don't ride for 3 days just have the battery charging for 3 days.

    question is - would that be a problem ? i know the chargers are supposed to be smart - but how smart are they really ?

    the light & motion charger seems pretty accurate - the amount of time the led stays red is proportional to the amount of time the battery was self-discharging "on a shelf" so to speak. and of course i have two identical ones and they both go green at approximately the same time so that gives me confidence that this charger is probably good enough for me to just leave it plugged in all the time ...

    on the other hand the Dinotte charger while it is much faster than the L&M charger ( 3 times faster ) sometimes the behavior is sketchy. sometimes i will come after a ride and it will show green and will not charge. i never had a problem with the light actually not working but sometimes it simply will not charge unless the battery is sufficiently depleted - so if it doesn't know when to start, how do i know if it knows when to stop ? i don't feel as safe leaving that charger plugged in all of the time.

    what do you think ?

  2. #2
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    They actually don't. The reason that most electronics discharge is that they are never really off. I believe this is true of the kindle. I think you will find that if you take the battery completely out of the kindle fully charged, it will do quite well for a very long time. On the other hand, NiMH (before Eneloops and similar) had a self discharge of something like 1% per day (something like that, don't recall). I have numerous Li-ion batteries that I put away charged and months later they are pretty much where I put them away.

    In general, you can leave batteries on the charger *if* they are a good float capable charger. That said, the batteries have a protection circuit in them and if it were to fail, or if the charger were to fail, you could have a potentially dangerous situation given the extreme flammability of Li based chemistries. So while it's ok, it's just better to not do it. There have been a number of cases of Li ion batteries catching fire either through faulty batteries or faulty chargers.

    When batteries are completely depleted, some of the chargers will try pulsing current in at a very low rate and then keep monitoring them. Often you can get the voltage of the battery to come up enough for the charger to recognize it as a live battery and to charge it normally.

    J.

  3. #3
    workin' it Administrator
    Reputation: rockcrusher's Avatar
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    I've reset the thread because after JohnJ80's post everything else was just 24 posts of waa waa waa. HTFU, take JohnJ80 off your ignore list or STFU. So damn much whining on here.
    Try this: HTFU

  4. #4
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    Pretty much I have to agree with what John said about leaving batteries on the charger. After they charge the charger should automatically stop charging but sometimes chargers can go a bit flaky. I've never had a 4-cell charger go wacky but since the possibility exist I try not to charge batteries unless I plan on being around to keep an eye on them. Never know if some circuit on the battery or if the charger might just do the unexpected. Better to be safe than sorry.

    He's also right about how some electronics use power even when the unit is supposedly off. Usually if this is the case the drain is very minute. Li-ion cells have very low self-discharge properties UNLESS something is wrong with the battery.

    Just last weekend I was at my computer desk when two power surges turned the electric on/off very quickly. Each time I had to re-boot the computer. Most of my big dollar electronics are on surge protectors but my battery chargers aren't. Glad I wasn't charging anything at the time.

  5. #5
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    thanks cat. i guess its a gray area.

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