Battery for tablet

Lord Bergamot

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Feb 21, 2015, 2:16:19 AM2/21/15

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The battery's gone wonky on my tablet. It takes a 3000 mah.
If I was able to get a battery, like maybe, a 6000 mah, would
it charge correctly, or would I need to go back with the same
type battery?

There is plenty of room for a larger size battery, longer, wider,
and even thicker. It would be easy enough to measure, I just
forgot to when I had the case open.

Is there a web site where I could get a new battery?
--
:-)
Don't let the Zombies get you!!!!

Ian Field

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Feb 21, 2015, 1:38:08 PM2/21/15

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"Lord Bergamot" <l...@dot.net> wrote in message
news:D4GdnTWSAYhdrXXJ...@giganews.com...

>
> The battery's gone wonky on my tablet. It takes a 3000 mah.
> If I was able to get a battery, like maybe, a 6000 mah, would
> it charge correctly, or would I need to go back with the same
> type battery?
>
> There is plenty of room for a larger size battery, longer, wider,
> and even thicker. It would be easy enough to measure, I just
> forgot to when I had the case open.

Just guessing - but its probably not unlike a laptop battery, in which case
almost certainly lithium.

Do not mess with lithium cells unless you know what you're doing!

Particularly multiple cells. They require a charge balancing system - if any
one cell gets over charged, it can go exothermic with a fairly entertaining
end of life performance.

Lord Bergamont

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Feb 22, 2015, 12:25:22 AM2/22/15

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That could be interesting.

The battery is flat, appx 5mm thick, 60 mm wide & 80 mm long.

I might open it again soon & get exact measurements. It would be easy to replace, if I knew where to get a battery.

Ian Field

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Feb 22, 2015, 2:20:04 PM2/22/15

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"Lord Bergamont" <L...@dot.net> wrote in message
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If its an actual flat cell in a heavy duty PVC pouch - they just flame - the
steel cased cylindrical type have safety vents, but I'm guessing these get
clogged with debris as the electrodes disintegrate. A youtube clip shows
someone deliberately shorting a cylindrical cell - several long boring
minutes of fizzing rather tamely culminated in the cell going off like a
firecracker. There was a small shower of sparks that could easily be a fire
risk, the steel case ruptured so if you're holding it you'd get lacerations,
the caustic burns would be a serious complication to healing.

Lord Bergamont

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Feb 28, 2015, 11:52:28 PM2/28/15

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There's a place in China that will sell me 1000 batteries, but not one by it's self.

Lord Bergamont

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Feb 28, 2015, 11:59:58 PM2/28/15

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I just checked EBAY and they have some there.

Ian Field

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Mar 1, 2015, 11:36:33 AM3/1/15

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"Lord Bergamont" <L...@dot.net> wrote in message

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Yesterday I scored a pack of 6x 18650 from the recycling bin at the
supermarket.

The previous haul was marked "Made in China" and had no laptop brand printed
on it - my main requirement is for e-cigarette batteries, I might designate
the Chinese cells for an application I don't hold near my face when I press
the button!

Lord Bergamont

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Mar 1, 2015, 4:50:37 PM3/1/15

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Chinese make cheap crap. Last night I tried to unplug a Chinese made adapter from the wall, it fell apart and I was almost electrocuted with 110 volts.

Some day I'm going to take time to look around trash bins at the supermarket. I've heard good things can be found.

Tim R

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Mar 1, 2015, 5:57:38 PM3/1/15

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Some laptop batteries are intelligent and won't charge unless conditions are met, won't overcharge, etc.

It may not be possible just to put any battery into a tablet, I dunno.

Lord Bergamont

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Mar 1, 2015, 7:46:57 PM3/1/15

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Tim R<timot...@aol.com> wrote:
> Some laptop batteries are intelligent and won't charge unless conditions are met, won't overcharge, etc.
> It may not be possible just to put any battery into a tablet, I dunno.

Oh well.. The battery I ordered was inexpensive enough it won't matter, and I'm ready to buy a new tablet, if it doesn't work.

Ian Field

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Mar 2, 2015, 12:34:22 PM3/2/15

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"Tim R" <timot...@aol.com> wrote in message
news:259e2b38-7247-4aee...@googlegroups.com...

> Some laptop batteries are intelligent and won't charge unless conditions
> are met, won't overcharge, etc.
>
> It may not be possible just to put any battery into a tablet, I dunno.

Most of the cells I've rescued for my E-cigarette seem to work just fine.

IMO; the 'intelligent' bit may often be a bit over zeallous.

Tim R

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Mar 2, 2015, 12:53:26 PM3/2/15

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We have an old Mac laptop with a missing charger.

I thought maybe I could remove the battery and charge it directly. There is not just + and GND on that battery, there are a lot of terminals and apparently a processor.

Ian Field

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Mar 2, 2015, 2:36:59 PM3/2/15

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"Tim R" <timot...@aol.com> wrote in message

news:e9023f33-f59b-4728...@googlegroups.com...

Multiple cell packs have sophisticated charge balancing circuitry - not all
cells are created equal, and the one that gets overcharged first goes
exothermic with fairly entertaining results.

You'd probably have to charge each cell individually - you could salvage the
end of charge shut off capsule from an e-cig and use a USB charger.

AFAICR: Most laptop chargers are 19V - you just need the right power jack
with the right centre pin polarity.

In the UK; I bought a universal laptop brick from Maplin (rip-off!) it has a
switch to select several voltages, and a rubber strip with an assortment of
changeable power jacks pressed into it.

Even at Maplin rip-off prices, it was probably a lot cheaper than most
genuine replacements.

whit3rd

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Mar 2, 2015, 6:38:52 PM3/2/15

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On Monday, March 2, 2015 at 9:53:26 AM UTC-8, Tim R wrote:

> We have an old Mac laptop with a missing charger.
>
> I thought maybe I could remove the battery and charge it directly. There is not just + and GND on that battery, there are a lot of terminals and apparently a processor.

Yeah, the battery and charge circuitry is smart, which means it's a mess to
tamper with. The 'missing charger', on the other hand, is just a voltage source,
you can get replacements cheap, compared to a battery replacement price.

Lord Bergamot

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Mar 3, 2015, 11:49:06 AM3/3/15

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There are only two wires on this tablet battery. When the solder
broke where the charger plugs in, before I soldered it, I charged
the battery directly, which might have been what caused the
battery to go wonky, although it never worked really great from
the beginning.

I always had to let the battery get down below 20% before plugging
in the charger, to keep it working good, and if I unplugged it before it
was fully charged it started having problems.

Tim R

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Mar 3, 2015, 12:21:10 PM3/3/15

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On Tuesday, March 3, 2015 at 11:49:06 AM UTC-5, Lord Bergamot wrote:

> I always had to let the battery get down below 20% before plugging
> in the charger, to keep it working good, and if I unplugged it before it
> was fully charged it started having problems.
>
> --
> :-)
> Don't let the Zombies get you!!!!

How old is this thing? "Memory" issues on rechargeable batteries, to whatever extent they existed, were solved decades ago.

Ian Field

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Mar 3, 2015, 1:14:09 PM3/3/15

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"Tim R" <timot...@aol.com> wrote in message

news:a9532fae-5a9c-4536...@googlegroups.com...

There's a specific end point voltage per cell that you shouldn't discharge
below, overcharging can also shorten cell life (sometimes very abruptly!).

AFAIK: there is no memory effect associated with any lithium cells.

Apparently some manufacturers make chips with a constant power charging
mode - over discharged cells need to be coaxed up gently to a normal state
before piling on the normal charge rate.

Lord Bergamont

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Mar 3, 2015, 2:14:39 PM3/3/15

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I bought it three years ago.

Except for the battery problems I've been happy with it.