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The IBM PalmTop PC110Batteries and power packs |
The PC110 is supplied with a LiIon 1200mAh battery. Rough battery life
is given below:
Configuration |
Expected battery life |
| PC110 + type III hard drive, no power management | up to one hour |
| PC110 + type III hard drive, with power management | between one and two hours |
| PC110 + type II flash card or CompactFlash card | between two and three hours |
These figures will vary depending on how you use the PC110.
Audio
I find audio playback to be a fair draw on the battery. Turn the volume down to the lowest that is acceptable, using <Fn><PgDn>.
PCMCIA cards
Different cards draw different amounts of current form the PC110. This is relevant to modems and flash cards, as well as hard drives. If you're not using a card, eject it.
Note that there is a 'hidden' parameter for PS2.EXE that allows you to enable the use of 3V PCMCIA cards. See the section on PS2.EXE for more details.
Hard drives
This is relevant to all rotating disk drives. These drives are one of your biggest power drains. Newer drives are more power-efficient, but don't be fooled into thinking that smaller capacity drives will use less power - my 40MB IBM drive draws 0.8A, whereas the 260MB Viper drive draws only 0.5A, and both drives are 5V devices.
If your operating system supports it, configure the hard-disk spin-down so that it shuts the drive off after three to five minutes of being idle. Remember that hard drives draw significantly more current when you start them than when they are running continuously, so be cautious about setting the spin-down to occur too frequently, or you could make the power consumption no better!
There is a small utility called HSLEEP.EXE available from somewhere that runs under DOS and powers off the hard disk. Again, I'll link to it when I recall where I saw it...
Modem
Using the modem will also draw power, so minimise your connection times.
Swap files and temporary files
Attempt to configure your operating system so that it uses non-mechanical storage for its temporary files - that is provided that you have space on flash cards to do so. If you've got lots of money, place your swap file on flash storage too!
RAMdrive
If you've got 20MB of RAM, and are using simple Windows applications, why not use a RAMdrive of 4MB or even 8MB to store commonly used files or applications? This would cut down on the need to access a hard disk, and so allow it to stay spun down. Remember it's volatile storage, though...
Processor speed
PS2.EXE
allows you to vary the processor speed between Fast, Medium, and Slow, which appear to equate to 33MHz, 16MHz, and 8MHz. Pressing <Fn><F11> should rotate through each of these in turn, but this doesn't seem to work under all conditions.If you're using text editing software, then you probably won't suffer if you slow the
processor down. Don't do this and expect reasonable performance from Windows or other
complex environments.
Hitachi market a camcorder battery called a VM-BPL13, which is identical to the IBM battery, bar the blue lettering (!) and the fact that the Hitachi one has a slightly higher capacity of 1350mAh. I purchased one of these recently, and use it daily.
Sony also have a range of batteries of roughly the same size as the PC110 battery - their NP-F520 and NP-F530 batteries have been reported to work in the PC110, and they have greater charge capacities. The ones I have seen are not identical, though.
If you change to a higher capacity battery, you may see that the charging guage reports that the battery is only something like 70% full when it finishes charging. To overcome this, use the hidden _@BATTERY OTHER parameter with PS2.EXE, and the guage should read correctly. Alternatively, Amanda Walker suggests that when charging has finished, popping the battery out of the machine, then putting it back in again, will cause the guage to read 100%.
The LiIon battery supplied with the PC110 has been suggested by some to have a life of around two years. Bear in mind that the first PC110's were made in September 1995, and that many recently-purchased new PC110's may have been sitting in various warehouses for over a year. My own LiIon battery is on the way out, I think, and I have only had my PC110 for five months - it stops charging at 60-70% (depending on temperature), regardless of the PS2.EXE settings. Still, batteries, even rechargable ones, are classed as consumables, and the Hitachi ones are affordable...
Remember when changing batteries that the backup battery (the little watch battery) will only power the PC110 for a maximum of one minute. It is always best to suspend the machine (<Fn><F4>) before swapping batteries, particularly if you're using a hard drive.
From Mark Willis:
"You can use one of these Li-Ion batteries to power your PC110; Canon BP-911: 1650 mAh Sony NP-F550: 1500 mAh Hitachi VM-BPL13: 1350 mAh IBM ?: 1200 mAh <stock battery>"
Seamus Waldron has details on his web pages of an external battery pack he made for use with his PC110 when travelling, which takes eight D cell batteries. His page quotes over 15 hours of theoretical battery life, but with realistic usage this drops to around 8 hours.
Thomas Harding also posted details of his battery pack, using eight AA cells, which I have included below for those who missed it. All the parts were found at Radio Shack.
Ok, the battery pack is part# 270-407a, the plug is part# 274-1533, the
batterys (AA NiMH) are part # 23-525 and the battery clip that fits the
battery holder is part# 270-325. The total cost of this external battery
pack is $44.77, and if you want en extra, you only need to get another
holder and 8 batterys. So for about half the price of an internal battery,
you can make an external, and I think it might last alittle longer, not
sure yet. I just want something cheaper to have as a backup. And Radio
Shack also has a charger that charges the NiMH AA batterys in 1 hour
($27.99)!!!!
Again, from Mark Willis:
"You can use a Radio Shack part number 273-1614 (10 VDC 850 mA) power lump to power your PC110, you may experience some problems once in a while with suspending etc. Costs about $15-$20 USD, I think."