I would like to share my experience to the community of converting a treo680 battery for Zire 72 battery pack replacement.
Since i have benefited in one way or another learning new things from the internet community and how some people's genuis in one way or another impressed me the things they have tried. Success or failure the community chip-in to share what they learned and in turn kept us moving forward (well the geeky guys & gals of the world).
Since getting a zire 72 battery replacement here (in our country) is a bit hard to come by, after finally found a forum that showed pictures and what to expect on a zire 72 take apart. After a few days of thinking about it, took all my courage to attempt to replace the battery which is about 3yrs old already on my bro's zire 72. Since battery life is noticably short (about 2hrs turn-on usage more or less). After a few hours of attempts in opening the case... success but not without battle scars, one of the hook on the tab was broken due to heavy strain in the attempts to seperate both screen and back case.
WARNING: The following instructions are of my personal experience. If you plan to proceed ahead you should realize should anything go wrong during your replacement you cannot blame me for the information provided. i post this to let everybody know that it's possible to convert a Treo 680 into a Zire 72 battery. I dont know if there will be future problems that will occur only time can tell. When you open your unit you will also void your warranty. I'm not a technician but i will provide information as much as i can to by ability only. PROCEED AT YOUR OWN RISK.
Before i discuss the steps it's wise to have protective gear since i done this without any i was a bit concerned about possible eye injury should things go wrong.
Here it goes... after i was able to successfully open the zire 72 case and successfully removed the battery. i then proceed in search for a replacement after 1 afternoon of searching can't find a shop that sell this pda battery replacement. After that saw my old nokia battery (left lying around but it's typically junk already) they both appear to be of the same size except the nokia battery is housed in a plastic casing. Since the nokia battery if of no use dismantling is in order to check for a compatible size battery. To my surprize it's almost the same size, which made me proceed to look for a higher capacity cell battery but to no avail. Most nokia replacement battery are only rated at 870mAH at the most which is less than the 920mAH original stock battery of the Zire 72.
Since i have a Treo 650, i checked the size of the battery which is more or less of the same size but the Treo 650 is too thick. Then i wondered about the Treo 680 which i know is a thinner battery compare to the Treo 650 battery because palm want to improve on the form factor of the next Treo compared to the fat Treo 650. To my surprize both battery (Zire 72 and Treo 680) are roughly the same size except the TTreo 680 battery is thicker by a few millimeter (later on this).
After purchasing a new Treo 680 battery, dismantling is no problem since it's like a printed sticker paper stuck on it not some metal housing (like AA batteries) removed.
Both battery are almost identical in size (Treo 680 on the label is rated to be 1200mAH Li-Ion battery) i chose Treo 680 battery since it's Li-Ion was afraid of Li-Polymer seen too many videos of Li-Polyer exploding into fire at one the popular video sites.
After opening both. before removing any component use a multi-meter to check the voltage just to see if it's working also it would be nice if the NEW battery has some charge left for checking if the contacts are connected properly. the negative side of the battery is located at the small PCB board of the battery (zire 72) while the entire body is positive side. If you notice the cell battery is not insulated only the small area where the negative side is insulated with something that looks like paper to me. removing the metal strip using a screw driver is no problem on the positive side but on the negative side you should be careful. Late last night i was too excited to assemble the new battery while attempting to remove the negative side of the metal strip the screw driver touch the body and there was a yellow-red spark which to my surprize i suddenly lift the screw driver to prevent damage to the small PCD board of the battery. With that incident, i decided to retire for the night and try again in the morning since thats enough for the night with that scarry thing happening to me (here i wished i had some protective gear for the eyes to insure safety).
The next morning since i proceeded with caution. taping the battery body with masking tape instead of electrical tape because the thickness of the electrical tape would push the battery thickness over the limit. Since the battery is already thick there could be a problem putting it back together if i chose the electrical tape. Taped the body except both ends of positive and negative sides. With last night sparky incident i decided to use fingers instead of screw driver to rip the metal strip away from the battery cell which is electric-welded. Carefull not to damage the battery pcb board we need it.
Then i made a mock up assembly of the battery by only taping the ends (positive and negative) checked the battery first with a multi-meter to insure there is electrical flow and made sure everythign is on the correct sides (positive is red, negative is black) just around here i touch the multi-meter on the terminal of the wires connecting to the board there was no response (no voltage) i got worried for a moment since i did everything correctly there should be some voltage response on the terminals. After trying a few times it appears the voltage did not show on the terminals of the pbc board where the plug with wires is connected but when i use the negative side and touch the metal strip it worked fine. After rechecking to insure there wont be a short-circuit, i proceed to connect the battery to the motherboard. PLUG-IN... the famous palm logo greeted me it was a success, since i plug the battery while the unit was at my bed when i lift the unit and wanted it to place it on the table the screen died down. Frantically attempted to press the power button after placing the unit on the table to turn it on, but to no avail. then i removed the plug then plug it again. tadaaa palm logo again wheewww what a relief this would only mean i should do some soldering to permanently connect the metal strip to the battery cell.
Reopened the battery cell, soldered the metal contacts of the pcb board to the battery cell then recheck. retape. recheck (for shortcircuit possiblity). then plug-in. Its' aaalivvveeeee !!! after than the unit showed me a low battery warning. i had to try the plug-in charger to see if it works. Before i try to plug in i kept some distance since i was afraid of it exploding or something. No problem so far. the unit showed that it's charging. after 1-2mins i removed the charger to see if the battery retained the charge. It did, so far so good.
Now time to reassemble everything. After 2 attempts to close the unit i discovered the battery thinkness is almost at the limit already. the unit wont close properly. I decided to open the battery taping package and retape it again this time more minimum to reduce the precious milimeter thickness i need in order the unit will close. Reused the old treo 680 label so that in the future i know what battery to buy should i attempt to change the battery for the 2nd time.
After several attemps i finally able to close the unit with a slight bulge on the bottom side due to the battery thickness taking care not to press to hard since the battery is pressing against the LCD at the back. also i removed 2 small plactic that is suppose to hold the battery in place. Removed it made possible to close the unit since its not blocked by the new battery. which is tightly fitted back to the battery compartment.
Then i made a bold step to fully charge the unit. Since it's the first time to charge i kept a watch on it, on how long it was charging since the battery is more like frankenstein it might go BESERK so careful watch is needed.
Right now am doing a drain test to see how long the battery life is (for the new battery). Since the original stock battery of the zire 72 is rated at 920mAH while the Treo 680 is rated 1200mAH (minimum as indicated on the label) That's 280mAH more battery power translate to 30.4% more power (from 920mAH). wondered if the power performance would be the same (meaning it should last longer, or longer usage)
So far so good it's working ok. but i will keep an eye on it everytime i try to charge it so as to avoid posible over charge. it does not mean the convertion did not work it's just to be on the safe side since the battery is a convert instead of the usualy battery purchased at the store.
Good luck for those who want to try to convert the battery. i would recomend you to purchase one if possible. my reason of converting a new battery for the zire 72 is purchasing one is a bit hard to come by here (in my country) and i want a bigger capacity battery anything above 1000mAH for longer usage.
Other related photos can be found here http://s249.photobucket.com/albums/gg225/netpower8