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Re: Should I completely discharge my laptop battery?

From "~misfit~" <shaun.at.pukekohe@gmail.com>
Newsgroups comp.sys.laptops
Subject Re: Should I completely discharge my laptop battery?
Date 2015-01-15 13:35 +1300
Organization A noiseless patient Spider
Message-ID <m971vf$1o8$1@dont-email.me> (permalink)
References (16 earlier) <m8nb7e$59c$1@dont-email.me> <m8q115$emf$1@dont-email.me> <m8q9et$q8d$1@dont-email.me> <m91koa$og2$1@dont-email.me> <m91rtt$fp8$1@dont-email.me>

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Once upon a time on usenet mike wrote:
> On 1/12/2015 3:18 PM, ~misfit~ wrote:
>> Once upon a time on usenet mike wrote:
>> [total snip]
>>> Are we having fun yet?
>>
>> Thanks Mike. I've copied that to notepad and saved it for when I
>> have a bit of time to play with.
>>
>> I have a couple of these too
>> http://www.dx.com/p/mp1405-5v-1a-lithium-battery-charging-board-blue-black-219454#.VLRT1MlZqUc
>> and used one for re-powering a mini rotary tool I got cheap that
>> used 3x small NiCad cells in shrink-wrap, the total size of which
>> was similar to a single 18650 but had little 'power' and didn't hold
>> much charge. I bought a new solder-tab Panasonic cell for that job
>> as I didn't know how good my slavaged cells were and it's hard to
>> open up the modded tool.... However it doesn't seem to like running a 
>> motor from the 'out' pads
>> - maybe it's something to do with the brushes and how it works? I
>> tried three of these PCBs for the job and they all didn't work
>> right. In the end I had to wire a small momentary contact switch
>> between the B+ and OUT+ pads to start the motor. Once it's started
>> it runs fine from the 'OUT' contacts. <shrug> As you can probably tell I 
>> only have basic knowledge (but try hard
>> to not take risks - I'm very aware of the inherant dangers with
>> Li-Ion tech and the potential for 'thermal runaway').
>>
> The website was translated into ChEnglish and doesn't make a lot of
> sense, but if I were to guess...

Sadly with that site you *have* to guess a lot (unless there are informed 
feedbacks).

> How are you switching the power?
>
> If you're switching between the battery and the board,
> that may be your problem.  Sounds like the board has to be powered
> up continuously.  I'd measure the drain from the battery in the
> off state.  May be inconsequential...maybe not.

I'm leaving the board and cell connected all the time. There doesn't seem to 
be much in the way of constant drain. I modded it a year ago and have only 
had to charge once in that time (it only gets light use).

> If you're switching between the board and the motor, the turn-on
> transient from the motor may exceed the 3A current limit.  Maybe a
> big cap across the out pads will help.

Hmmm, yes that might indeed be the problem - thanks. (I told you I have only 
basic knowledge of electronics. However I have a cheap rework station that I 
haven't unpacked yet which was delivered today so I better learn more!)

There's not much room in the enclosure for a 'big cap' - or anything else 
for that matter. I dismantled it several times, re-soldering and hot-gluing 
it all in place each time. The last time /was/ the last time - I taped it up 
good (as the plastic threads for the screws weren't made for repeated use 
and stripped quickly). I'll use it as-is now I think but it's good to know 
how to combat this issue if I use one of the other modules.

Silly me; Where it says "charge current 1,000mA max" I took that to mean 
what the board will put into the cell - not what the board would take. I was 
charging my 3,000 A/h cell from a 500mA source and it was taking hours so 
hooked it up to my 2,000mA plugpack. Well, I shouldn't have walked away for 
the ~30 minutes that I did! Seems it was dumping extra current as heat, 
there was hot glue running out of it! I thought that it would just 'take' 
what it could handle from the source? <shrug>

Cheers,
-- 
Shaun.

"Humans will have advanced a long, long, way when religious belief has a 
cozy little classification in the DSM."
David Melville (in r.a.s.f1) 

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Thread

Should I completely discharge my laptop battery? andymhancock@gmail.com - 2014-12-30 11:53 -0800
  Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2014-12-31 13:35 +1300
    Re: Should I completely discharge my laptop battery? andymhancock@gmail.com - 2014-12-31 11:06 -0800
      Re: Should I completely discharge my laptop battery? andymhancock@gmail.com - 2014-12-31 11:54 -0800
        Re: Should I completely discharge my laptop battery? andymhancock@gmail.com - 2015-01-01 15:13 -0800
      Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-01-01 12:29 +1300
    Re: Should I completely discharge my laptop battery? mike <ham789@netzero.net> - 2014-12-31 12:05 -0800
      Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-01-01 12:55 +1300
        Re: Should I completely discharge my laptop battery? andymhancock@gmail.com - 2015-01-01 14:51 -0800
          Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-01-02 14:16 +1300
            Re: Should I completely discharge my laptop battery? andymhancock@gmail.com - 2015-01-01 18:11 -0800
              Re: Should I completely discharge my laptop battery? mike <ham789@netzero.net> - 2015-01-02 01:15 -0800
                Re: Should I completely discharge my laptop battery? andymhancock@gmail.com - 2015-01-02 09:34 -0800
                Re: Should I completely discharge my laptop battery? mike <ham789@netzero.net> - 2015-01-02 10:46 -0800
                Re: Should I completely discharge my laptop battery? andymhancock@gmail.com - 2015-01-02 14:25 -0800
                Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-01-04 12:28 +1300
                Re: Should I completely discharge my laptop battery? andymhancock@gmail.com - 2015-01-03 16:48 -0800
                Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-01-07 14:47 +1300
                Re: Should I completely discharge my laptop battery? mike <ham789@netzero.net> - 2015-01-06 19:38 -0800
                Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-01-09 13:36 +1300
                Re: Should I completely discharge my laptop battery? mike <ham789@netzero.net> - 2015-01-08 17:34 -0800
                Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-01-10 14:59 +1300
                Re: Should I completely discharge my laptop battery? mike <ham789@netzero.net> - 2015-01-09 20:22 -0800
                Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-01-13 12:18 +1300
                Re: Should I completely discharge my laptop battery? mike <ham789@netzero.net> - 2015-01-12 17:20 -0800
                Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-01-15 13:35 +1300
                Re: Should I completely discharge my laptop battery? mike <ham789@netzero.net> - 2015-01-14 17:37 -0800
                Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-01-16 12:33 +1300
                Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-02-08 14:24 +1300
                Re: Should I completely discharge my laptop battery? mike <ham789@netzero.net> - 2015-02-07 21:02 -0800
                Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-02-11 11:09 +1300
                Re: Should I completely discharge my laptop battery? "~misfit~" <shaun.at.pukekohe@gmail.com> - 2015-01-03 11:47 +1300

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