Often enough we get asked, which battery goes with my battery operated soldering irons?

Model 7700, 7740 soldering irons replacement battery P/N 7733 battery.

**Please note the #7733 battery is now a black shrink wrap rather than the white, as of December 2017.

Iso-Tip Model 7904, 7944 soldering irons replacement battery P/N 7933.

If you’re looking to replace the battery in our 7800 Fast Charge, click here for a different how to.

Quick Fix

Battery Operated Soldering Irons

Replacing the battery in our #7700 and #7904 is simple. These instructions are also included in the product manual.

  1. Pull out three screws from the case. Disassemble cover carefully.
  2. Remove switch contact screw. Lift switch spring and tip holder assembly up and remove from the unit.
  3. Remove battery pack by removing two screws at ends of battery pack. Keep your screws!
  4. Install the new battery with those two screws we told you to keep.
  5. Replace switch spring and tip assembly in case. Use caution! Do NOT touch the other tip assembly.
  6. Replace switch contact screw.
  7. Replace cover and three screws.
  8. Let your soldering iron charge for 4-6 hours.

Iso-Tip Battery Operated Soldering Irons Rebuild Program

Most of our customers are really smart humans…after all they bought from us and they know how to fix stuff. As a loyal Iso-Tip customer, you have several options when replacing this battery. First option is to just send it in to us and let us go through the tool, then test and repair anything else the iron or charger may need. Here’s more information about our rebuild program. The other is for do it yourself, which we all like to try at least twice. All this information can be found in your product manual that came with the tool, but if you’re like us you’ve misplaced it, so here’s an electronic copy. Happy Soldering!

Other Battery FAQs

  • What kind of battery does it use?
    • Nickel-cadium (NiCd) battery. Please dispose of properly.
  • Why NiCd, there are so many other batteries on the market?
    • Every year we review the batteries out there, and right now the NiCd is the best on the market for our tools. Although, we are excited about a few new things happening in that world. If it’s not broke, don’t fix it!
  • My boss requires I have a safety data sheet, can I get one for the battery from you?
  • I have a yellow soldering iron (#7800), is replacing the battery just as easy?
  • If I leave my Iso-Tip in the charging stand, will it over charge?
    • You CAN leave your Iso-Tip in the charger when not in use – it will NEVER over-charge. The charger can be unplugged if long periods of non-use are expected. If the soldering iron is left in the stand and the recharging stand is disconnected or turned off the iron will discharge.
  • What if I don’t solder that often?
    • Insure a longer battery life by using the tool frequently. Even when you don’t solder, it is a good practice to completely discharge the batteries by normal use at least once a month. Batteries can lose their max capacity if this is not done.
  • I have a yellow charger, can I charge my grey iron with it?
    • NEVER charge your Iso-Tip soldering iron in a re-charger stand that is a different color than the iron. The higher charge rate of different colored stands may cause overcharging and overheating of the iron’s re-chargeable cells, and this will shorten battery life.
  • What if I’m not comfortable with replacing the battery myself?