[ltp] Running with line power and no battery

[Henrique de Moraes Holschuh]

On Fri, 29 Feb 2008, David A. Desrosiers wrote:
> 1. Plug in the laptop with the battery attached, use it until the
>    "Battery is fully charge" alert comes up, then disconnect AC, and
>    run exclusively on battery. When the low-power alert comes up, plug
>    AC back in and continue to work until the laptop battery is at 100%
>    charge again. 
> 
>    Lather. Rinse. Repeat.

This is wonderful for NiMH batteries, but will hurt a Li-ION one so bad it
is not funny.

> 2. Charge battery to full while on AC, then remove the battery, working
>    only on AC power. When you need to disconnect from AC (or work
>    mobile), plug the battery in and use until the low-power alert comes
>    up. At this point _switch_ the battery for a full-charged second
>    battery.

Standard "executive" mode of operation.  It is also bad for Li-ION
batteries, but an executive could care less, five seconds of his time are
worth more than one battery pack.

Or so would they like to believe, anyway.

>    Take the first battery and use the "Battery Rundown" tool to fully
>    drain the battery (usually will provide at least 1 more hour of
>    "life" past the low-battery audible warning alerts). I've usually

This is to make sure to make the pack suffer as much as possible or what? It
only makes sense for NiMH, but it kills Li-ION :-)

> Both of these approaches seem to rapidly kill Thinkpad batteries (direct
> from IBM, not third-party replacements). 

No wonder it does...

> I spoke to an IBM tech at one point about #1 above, and he recommended
> that as the best way to ensure you don't "prematurely age" the battery.

The tech is an incompetent chap who doesn't know the difference between NiMH
cells and Li-ION cells.

> > My 9-cell and bay batteries are at 95% of their design capacity after
> > two years of use (proper storage at 10C).
> 
> 10°C is 50°F... are you storing these in your refridgerator in a ziplock
> or something? Keeping them in a metal container in your basement or

They are kept in the refrigerator, inside a ziplock with humidity-absorving
gel packs.   I take them out once every two months, let them get to ambient
temperature slowly, dry any left over moisture from the heat up, then I
check if they did not lost too much charge.  If they did, I use them for a
bit to check if they're fine and recharge, then back to the refrigerator
they go.

The Li-polimer bay battery is specially bad at it, you have to give it a
recharge every so often, or it drains itself too low.

Obviously before a trip, I plug them into the thinkpad and leave it charging
them overnight.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh