HP ob300-530_battery_rebuild free download

File name ob300battery.txt

OB300-530 battery rebuild procedure. I start with a wide, rounded-edge flat-blade screw driver, specifically the one that is in my Victorinox Champ Swiss Army Knife. I carefully work it between the plastic case seams and slowly work around the edges until I have completely broken the ultrasonic weld. After I have done that, I carefully cut out the old batteries, close to the cells. I leave the metal strips (tabs) coming from the case connectors as long as possible. Make note of cell polarities and use a Sharpie or other permanent marker to mark the plus-ends of the cells in the bottom-half of the battery case for future reference. There is a diode, a high-temp thermal fuse, a low-temp resetting thermal cutout (rectangular device with leads coming out of one end, one of them connected to the high-temp thermal fuse) and a current limiting resistor in series with the cells. Leave the diode between case connectors intact. You will not be able to salvage the high-temp thermal fuse (shaped like a tiny bullet with leads out both ends) unless you use a hemostat heat-shunting clamp when re-soldering. I usually discard the high-temp thermal fuse and the current limiting resistor (small, flat, white thing between the left cells, when bottom-case half contacts facing up and top the right). I use NiMH cells from DigiKey with solder tabs. The tabs make assembly MUCH easier. Soldering directly on the cells is both dangerous and difficult. Manufacturers and volume-rebuilders use a miniature spark-welder. Unless you are rich, you will want to use a quality soldering iron with a fine tip. www.digikey.com Catalog page 518. Part #P016T-ND $4.93ea. $44.33/pack of 10 I start with the two left cells first (bottom-case half contacts facing up and to the right). Once I get the cells in place, noting polarity, I carefully fold the solder tab strips to allow them to extend from the left half of the battery case to the right half in the little grooves that were used by the old batteries. Using Scotch tape to temporarily maintain this rotational alignment, I then remove the cells from the bottom and fold the far-left tabs so they overlap. I now solder the tabs together and put the cells back into the lower-half of the battery case. Always be careful not to melt the plastic skin on the battery and short it out at the top. Now I work on the right side. I place the two cells (note polarity again) in the case and rotate them so I can get the solder tabs lined up. Starting with the lower-right cell, I take its left tab and fold it to meet the right tab from the lower-left cell. I now note the rotational alignment of the cell and remove the cell and fold his right tab to interconnect with the tab coming from the appropriate case connector. I clip the excess left-tab with my Army Knife scissors and then solder the bottom cell tabs together. Don't solder the right-tab just yet, you need to