Battery folklore

[gareth evans]

Old ASUS Laptop, about 7 years old, single CPU, Windows XP

Not really used, but kept in reserve, just in case.

I have a spare battery for it.

Every fortnight or so, I run it up to keep the battery
charged, and then swap the two battery packs and run it up
again.

Usually, when the other battery is put in, it first
reports about 98% full before recharging to 100%

Strangely, the last two swap-overs, for both batteries,
when first run up, it says almost discharged at about 5%.

I think it unlikely that both batteries have suddenly
developed a high self-discharge rate when on the shelf
over a two-week period,
so this suggests to me that something must be amiss
with the Laptop itself.

Any clues, similar experiences out there?

TIA

[gareth evans]

PS. The reason that I keep the old Laptop is that it
has a parallel printer port and is the only means
that I have to occasionally use the HP Laser printer
when I need a hard copy that is not subject to water
damage.

Post by gareth evans
Old ASUS Laptop, about 7 years old, single CPU, Windows XP
Not really used, but kept in reserve, just in case.
I have a spare battery for it.
Every fortnight or so, I run it up to keep the battery
charged, and then swap the two battery packs and run it up
again.
Usually, when the other battery is put in, it first
reports about 98% full before recharging to 100%
Strangely, the last two swap-overs, for both batteries,
when first run up, it says almost discharged at about 5%.
I think it unlikely that both batteries have suddenly
developed a high self-discharge rate when on the shelf
over a two-week period,
so this suggests to me that something must be amiss
with the Laptop itself.
Any clues, similar experiences out there?
TIA

[Dave Garland]

Post by gareth evans
PS. The reason that I keep the old Laptop is that it
has a parallel printer port and is the only means
that I have to occasionally use the HP Laser printer
when I need a hard copy that is not subject to water
damage.

Post by gareth evans
Old ASUS Laptop, about 7 years old, single CPU, Windows XP
Not really used, but kept in reserve, just in case.
I have a spare battery for it.
Every fortnight or so, I run it up to keep the battery
charged, and then swap the two battery packs and run it up
again.
Usually, when  the other battery is put in, it first
reports about 98% full before recharging to 100%
Strangely, the last two swap-overs, for both batteries,
when first run up, it says almost discharged at about 5%.
I think it unlikely that both batteries have suddenly
developed a high self-discharge rate when on the shelf
over a two-week period,
so this suggests to me that something must be amiss
with the Laptop itself.
Any clues, similar experiences out there?

You're right, you wouldn't expect both going bad at exactly the same
time. If you've always balanced the load between them, they'll wear
out at approximately the same rate, but wouldn't expect quite that
degree of synchronization.
Maybe the charger circuit is not adequately charging them?
Maybe the charge detection (probably by measuring battery voltage) has
gone bad? (Which could also lead to the charge stopping too soon
because it thinks they're full.)
You might try seeing how long one of those "5%" batteries will
actually provide power. One full discharge shouldn't unduly damage
them, and if you got 6hr or so that would prove the level shown was
incorrect.
Do they show the same 5% whether they're in the computer or out if it?

FWIW, charging to 100% isn't real good for Li batteries, they do best
if you avoid that last 10% full & empty. NiCd likes to be fully
discharged once in a while, and just topping off can lead to "memory
effect" reducing the amount of charge it will hold, but your computer
probably isn't so old as to have NiCds. NiMH have a normal
self-discharge of about 1%/day, and may need a full discharge/recharge
if they've been out of use a long time.

[Fred Weigel]

Post by gareth evans
Old ASUS Laptop, about 7 years old, single CPU, Windows XP
Not really used, but kept in reserve, just in case.
I have a spare battery for it.
Every fortnight or so, I run it up to keep the battery
charged, and then swap the two battery packs and run it up
again.
Usually, when the other battery is put in, it first
reports about 98% full before recharging to 100%
Strangely, the last two swap-overs, for both batteries,
when first run up, it says almost discharged at about 5%.
I think it unlikely that both batteries have suddenly
developed a high self-discharge rate when on the shelf
over a two-week period,
so this suggests to me that something must be amiss
with the Laptop itself.
Any clues, similar experiences out there?
TIA

These batteries have 300 (or so) full/empty charge cycles. The self-discharge
rate is very low. Buy two new batteries. Charge to 70% and put one away.
There should be a tool that tells you the ACPI info about the battery.

You will only need to check the charge of the spare every 6 months. LI is not lead-acid.

Something along these lines:

: ***@tara dl #; acpi -i
Battery 0: Full, 100%
Battery 0: design capacity 4400 mAh, last full capacity 4144 mAh = 94%

I imagine that someone can point you to a suitable windows utility. Google
gives me the following:

https://superuser.com/questions/333329/windows-xp-vista-7-check-battery-charge-from-cmd

[John Levine]

Post by Fred Weigel
These batteries have 300 (or so) full/empty charge cycles. The self-discharge
rate is very low. Buy two new batteries. Charge to 70% and put one away.
There should be a tool that tells you the ACPI info about the battery.

Naah. If he's just keeping the laptop to drive a printer, he can get
a USB->parallel cable for about $10 which is a lot less than a replacement
battery.

[philo]

I don't know if I've ever posted here before but I found the subject interesting.
I was a field service engineer in the battery business.

Though I worked with lead acid batteries there are some things common to all batteries and they do not have to be charged every few weeks.

For a lead-acid battery, every 90 days would suffice and with an LI battery one could go much longer.

Much to my surprise, my Lytro camera with LI battery which had been in storage for eight years actually charged up and worked!

[David Lesher]

Post by John Levine
Naah. If he's just keeping the laptop to drive a printer, he
can get a USB->parallel cable for about $10 which is a lot less
than a replacement battery.

If the newer box has printer drivers for the older printer.

[Ahem A Rivet's Shot]

On Tue, 14 Sep 2021 05:51:18 -0000 (UTC)

Post by David Lesher
If the newer box has printer drivers for the older printer.

It's an old HP it will talk PCL and perhaps PostScript, should be
no trouble to drive it.

[Bob Eager]

Post by Ahem A Rivet's Shot
On Tue, 14 Sep 2021 05:51:18 -0000 (UTC)

Post by David Lesher
If the newer box has printer drivers for the older printer.

It's an old HP it will talk PCL and perhaps PostScript, should be
no trouble to drive it.

I use a 1993 HP LJ4M+. The drivers are still OK. They aren't actually
shipped with Windows 10, but it will find them.

On FreeBSD, support from cups is fine.

[David Lesher]

Post by Ahem A Rivet's Shot
On Tue, 14 Sep 2021 05:51:18 -0000 (UTC)

Post by David Lesher
If the newer box has printer drivers for the older printer.

It's an old HP it will talk PCL and perhaps PostScript, should
be no trouble to drive it.

Maybe. I learned the hard way that such is not true for the far
more expensive larger HP plotters. W7 driver, yep; W10, nope....

[John Levine]

Post by David Lesher

Post by Ahem A Rivet's Shot
It's an old HP it will talk PCL and perhaps PostScript, should
be no trouble to drive it.

Maybe. I learned the hard way that such is not true for the far
more expensive larger HP plotters. W7 driver, yep; W10, nope....

Plotters are different, HP never had a common language for them.

All printers, from HP and otherwise, have spoken PCL and Postscript for
a long time, so I would be very surprised if this printer didn't.

Even if you can't find a driver for that specific model, a driver for
some other HP with similar features or a generic PCL or Postscript
driver should work.

[David Lesher]

Post by John Levine
All printers, from HP and otherwise, have spoken PCL and
Postscript for a long time, so I would be very surprised if
this printer didn't.
Even if you can't find a driver for that specific model, a
driver for some other HP with similar features or a generic PCL
or Postscript driver should work.

I've wasted hours on such situations. Often it prints, but on
half the page, or such. On a Brothers, I could get monochrome
but not color.

If it's Postscript, and a Mac, with native Postscript output,
it's easy. But without, it's a time sink.

[Bud Frede]

Post by David Lesher

Post by John Levine
Naah. If he's just keeping the laptop to drive a printer, he
can get a USB->parallel cable for about $10 which is a lot less
than a replacement battery.

If the newer box has printer drivers for the older printer.

A pox on printers that require special drivers. :-)

[J. Clarke]

Post by Bud Frede

Post by David Lesher

Post by John Levine
Naah. If he's just keeping the laptop to drive a printer, he
can get a USB->parallel cable for about $10 which is a lot less
than a replacement battery.

If the newer box has printer drivers for the older printer.

A pox on printers that require special drivers. :-)

I've got a Panasonic that's like that. I used to run a laptop with
Windows 95 as a RIP for it until the toners started giving out. It's
the same engine as a Tektronix Phaser but with a Winprinter interface
instead of PostScript. At this point it's a boat anchor--I can get a
new printer with better peformance for the price of one of the four
toner cartridges it needs. But it's such a big boat anchor that I've
never gotten around to hauling it to the dump.

[Peter Flass]

Post by J. Clarke

Post by Bud Frede

Post by David Lesher

Post by John Levine
Naah. If he's just keeping the laptop to drive a printer, he
can get a USB->parallel cable for about $10 which is a lot less
than a replacement battery.

If the newer box has printer drivers for the older printer.

A pox on printers that require special drivers. :-)

I've got a Panasonic that's like that. I used to run a laptop with
Windows 95 as a RIP for it until the toners started giving out. It's
the same engine as a Tektronix Phaser but with a Winprinter interface
instead of PostScript. At this point it's a boat anchor--I can get a
new printer with better peformance for the price of one of the four
toner cartridges it needs. But it's such a big boat anchor that I've
never gotten around to hauling it to the dump.

That”Winprinter” thing is the biggest piece of garbage to come down the
pike in a while. I understand the reasoning, sort of, from the time when
logic was expensive. Heck, the IBM 1130 supported most of its peripherals
that way, but the fact that that it wasn’t documented is an abomination.
The fact that there are any devices whose interface is undocumented is an
abomination. i

[Ahem A Rivet's Shot]

On Sun, 19 Sep 2021 17:48:33 -0700

Post by Peter Flass
That”Winprinter” thing is the biggest piece of garbage to come down the
pike in a while.

I refer you to the abominable Winmodem.

[chris]

Post by gareth evans
Old ASUS Laptop, about 7 years old, single CPU, Windows XP
Not really used, but kept in reserve, just in case.
I have a spare battery for it.
Every fortnight or so, I run it up to keep the battery
charged, and then swap the two battery packs and run it up
again.
Usually, when the other battery is put in, it first
reports about 98% full before recharging to 100%
Strangely, the last two swap-overs, for both batteries,
when first run up, it says almost discharged at about 5%.
I think it unlikely that both batteries have suddenly
developed a high self-discharge rate when on the shelf
over a two-week period,
so this suggests to me that something must be amiss
with the Laptop itself.
Any clues, similar experiences out there?
TIA

Batteries have their issues. I have several battery power
tools, laptops and other rechargeable battery powered kit,
not all of which is used regularly. Nicads tend to die if
not topped regularly, but remembering to do that can be a bit
of a chore. To get round it, built a board with a time
switch, 25 amp relay to handle surge current, and two rows
of 4 power sockets. Time switch can be set to any on / off
times, but have found the optimum time to keep the batteries
topped up is around 1/2 an hour per day. Too much results
in overcharge, while too little discharges over time. Seems
to work ok and something else I don't have to remember to do
any more. So far, 7 of the 8 sockets used...


Chris

[Andreas Kohlbach]

Post by gareth evans
Old ASUS Laptop, about 7 years old, single CPU, Windows XP

Sure not older?

Mine is 9 years old and came with Windows 8. Still have its hard disk
(wonder if it would spin on at all today after almost 9 years not being
used) but put an even older (with originally Windows Vista on where I
installed the Linux running in front of me back then).

Post by gareth evans
Not really used, but kept in reserve, just in case.
I have a spare battery for it.
Every fortnight or so, I run it up to keep the battery
charged, and then swap the two battery packs and run it up
again.
Usually, when the other battery is put in, it first
reports about 98% full before recharging to 100%
Strangely, the last two swap-overs, for both batteries,
when first run up, it says almost discharged at about 5%.
I think it unlikely that both batteries have suddenly
developed a high self-discharge rate when on the shelf
over a two-week period,
so this suggests to me that something must be amiss
with the Laptop itself.

Suppose it needs to be re-calibrated to show what's really going on.

Post by gareth evans
Any clues, similar experiences out there?

Mine holds the charge for 5 minutes or so, 30 if the lid is closed. Lucky
you!

I keep it to buffer small power outages (less than 30 minutes). The last
lasted four hours which the battery could not cover. Setup is
auto-shutdown when battery is at 5%. But charge dwindles so quickly an
orderly shutdown wasn't even triggered according to my logs.

[danny burstein]

In <***@usenet.ankman.de> Andreas Kohlbach <***@spamfence.net> writes:

[snip]

Post by Andreas Kohlbach
Mine holds the charge for 5 minutes or so, 30 if the lid is closed. Lucky
you!
I keep it to buffer small power outages (less than 30 minutes).

Keep in mind it's also buffering those half second or so glitches
when the utility transformer 25 miles away kicks on, or
off... and that power surge, or hole... blinks out
your lights and clocks.

[gareth evans]

Post by Andreas Kohlbach

Post by gareth evans
Old ASUS Laptop, about 7 years old, single CPU, Windows XP

Sure not older?
Mine is 9 years old and came with Windows 8. Still have its hard disk
(wonder if it would spin on at all today after almost 9 years not being
used) but put an even older (with originally Windows Vista on where I
installed the Linux running in front of me back then).

Actually, you are probably correct for this laptop I am on
currently is 7 years old and was previously W7 before
upgrading to W10 (Big mistake!) and the laptop with the
battery problem was an even earlier one.

But it's not the oldest here, for I've a W95 one and its
flat screen is about the size of a postcard!

[Douglas Miller]

Laptop batteries, at least those of a certain vintage, have an IC on them that manages charging and reports status to the host. I think it uses I2C or some such communication method. I've had a laptop battery controller chip get confused about the battery state, and either didn't report it was fully charged even though it was, or else thought it was fully charged and so didn't re-charge it. I somehow found a utility to reset that chip, and was able to get a few more years of life out of battery. All this to say, the actual battery cells may be fine. Also, depending on the vintage, your battery may not contain Li-ion but rather NiMH or NiCad. If the laptop was actually designed 7 years, probably Li-ion. (I had a bad habit of buying laptop models that were at end-of-life, so their design age was as much as +5 years from when I purchased)