Toshiba Portege 300CT --> 7020CT Battery Swap

Click on the thumbnails, yo.

December 19, 2002
Received my used Portege 7020 laptop from a company on eBay.

December 20, 2002
Battery turned out to be DOA.

December 21, 2002
I had a spare normal battery pack from my old Portege 300CT. After taking a few physical measurements, and comparing the case dimensions side by side, I figured that the actual lithium cells inside were probably about the same size. Electrically, they were both 10.8V ~2400-2500mAh packs.

So I cracked open the cases and took a look. They were identical cells with different connector/recharger electronics. Being the curious tinkerer I was, I decided that it would be pretty sweet to switch the cells and see what happened. The major snag that I foresaw was a difference in the connectors. Between the old Portege 300 and the 7020, the size of the connector shrank and moved off center. Being the lazy engineer that most of us are when faced with a lab situation, I chose the fewest solder points to detach on both packs and attacked the problem.

It took me about 5.5 hours to desolder both control electronic sets, run jumper cables, and reattach the jumper cables to the new cells, all the while maintaining the right order of connections. Basically, so long as the right voltages were connected to the right terminals on the new PCB, it would function identically.

The addition of the extra 2-3mm of 22 gauge insulated wire put even more space constraints on the internals of the battery pack. But I managed to fit everything back together roughly as it had come out. I squeezed the case back together, and plugged the battery pack in. The laptop was actually switched on when I had the opportunity to test my handiwork. When the yellow charging light flickered on, I knew that everything was a-ok. No overheating, no problems beyond a Power Management mis-read. I made sure to fully discharge and recharge the pack, which took care of that issue.

April 9, 2003
Caveat: The battery pack I installed in place of the dead cells only lasts 25 minutes. There are a few potential explanations. First, the 7020CT is much more feature rich system, with a faster processor, larger screen, and a hard drive that uses twice the power (1A @5V instead of 500mA @5V). So does that mean it should run half as long? Maybe. The old laptop screen was 10.4", the new one is 13.3", 63% larger, if not more. Since the cells themselves are identical in voltage and amp-hours, there is some consistency to the idea that with all other components' consumption raised by ~50%, the battery life would be cut back. Indeed, my 300CT would usually get about an hour and a half on the standard battery pack. Which means that the extended-life pack for the 7020CT is probably only good for about 50-90 minutes.

After several months of using this laptop on a daily basis, I have to report that I am completely satisfied with it. It's fast, efficient, and miles away from the old one (except for batt. life).

May 16, 2003
Update: When all of the power-saving features of the laptop are turned on, e.g. scaling down the processor speed, turning down the backlight brightness, etc. I can squeeze about 45 minutes worth of use out of a fully charged battery.

November 2003
Well, the battery-swapped pack finally died. The cells refused to hold a charge, so the laptop was reduced to being an expensive paperweight when not connected to the mains, and worse yet, would shut off during power dips.

Frustrated with this situation for a few months, I ordered a PA3002U-1BRL / PA2506UR long life battery pack off of eBay for about $40. For anyone looking for information on these battery packs, the PA3002 is supposedly for the Portege 7200 series, but it works fine in the 7020. The pack arrived a few days later and works like a charm, running four hours between charges. More importantly, I discovered a gem of a power-management utility that's available for free from Toshiba!

Check this out: It's called Toshiba Power Saver, and it takes over all of the power management functions using the Portege's ACPI functionality. All of the features work as you would want them to and as a utility it is a model of good User Interface design.

For instance:

A mouse-over on the light bulb looks like this.
Left mouse-click does this.
Right mouse-click does this.

A double-click opens up a list of power-saving profiles that you can select on the fly. Three pre-configured profiles exist, each with variations on screen brightness, processor speed, time to suspend and hibernate, and time to hard drive spindown.

Overall, it's pretty sweet, it works flawlessly, and lets you really extend the runtime of the battery. The laptop's Standby mechanism is fairly impressive as well, I've left the laptop in Standby mode for over eight hours with only a 20-25% drain on the battery over that time, and the system resumes in an instant.

If this helped you out at all, feel free to get in touch with me at research@vilimpoc.org.