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
Replacing the battery in our #7700 and #7904 is simple. These instructions are also included in the product manual.
- Pull out three screws from the case. Disassemble cover carefully.
- Remove switch contact screw. Lift switch spring and tip holder assembly up and remove from the unit.
- Remove battery pack by removing two screws at ends of battery pack. Keep your screws!
- Install the new battery with those two screws we told you to keep.
- Replace switch spring and tip assembly in case. Use caution! Do NOT touch the other tip assembly.
- Replace switch contact screw.
- Replace cover and three screws.
- 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?
- Of course! Here’s a link.
- 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?
- Send it into us for our rebuild program. Here’s a link that explains more.
What is the normal rate of self-discharge for a 7700 battery?
Or, what is ~half-life of charge if not in the charger?
Is a high self-discharge rate a sign of an elderly battery?
Thanks
For the 7700 normal battery life (discharge rate) would be 125 solder joints per full 4 hour charge.
Your YouTube review says this can be plugged directly to 110 Volts as the charging circuit is in the Iron. That is obviously incorrect and very dangerous to attempt.
You are correct, you should not do that. Any reviews you see on YouTube are from end users not associated with Iso-Tip. Would you mind giving a link to the video that stated that? I would like to reach out to the creator of that video and ask them to make a correction.
Hi Folks,
It looks like I got my new battery changed. My only issue was with the contacts that fold down from the ends of the battery. The didn’t line up with the contacts in the body of the tool and some “finagling” with a pair of pliers was required. Not too big a deal but one that might be addressed in the instructions.
Bob Bennett
It looks like I just changed the battery. Only issue was that the contacts on the battery ends didn’t line up with the contacts in the body of the tool. Some “finagling” with a pair of pliers seems to have worked.
Bob Bennett
Hello Bob
It sounds like you’ve got an older iron on your hands. The old irons have a slightly different body than the current ones, so the battery tabs don’t line up quite right. That’s a good suggestion, and one that we will make sure to let users know going forward.
I have an old orange iron # 7700 (WAHL). It is a great tool
The charger is different from the new gray # 7700 in that the transformer is external to the charger.
Can this orange model be left in the charger without overcharging?
Thank you
Yes, you can leave the orange model in the charger without it overcharging. There aren’t too many of the orange ones still around, so it’s good to hear that yours is still working!
Thanks for the reply.
It is a great tool and worked flawlessly for several decades. It only required battery and tip changes
My 7700 has a NiCd battery. Can I replace it with NiMh?
Yes, you can replace a NiCd battery with a NiMh battery. Just make sure that it’s 2.4V and isn’t too large to fit in the case.
I have an orange model 7700 (Wahl) soldering iron that I inherited from my father. I had to replace the batteries and now it works great again. I’ll be ordering new tips for it now that I found you.
Glad to hear that your iron is up and running again! We take great care in all the irons we build, so I’m happy that yours continues to serve you well after all these years.
I am looking for a replacement battery for the Iso-tip Model 7550. Does anyone know where to get one or an equivalent.
Sorry, I put the wrong model #. It is a Iso-tip 7575 that needs a battery.
Our 7733 battery should work as a replacement for the 7575.
i am in need off battery for model 7700.
Please share the link to online purchase.
Hello, here’s the link to our 7700 replacement battery, you can purchase directly online: https://iso-tip.com/product/quick-charge-replacement-battery-7733
What voltage should be measured from the Wahl 7500 charger?
The output should be about 1.7 volts.
My Isotip 7700 had not been used a great many years. The battery had corroded with a lot of white powder at both ends of the battery. The screw that the copper switch contacts with is corroded as well.
1. How should I clean up the contact screws and other corrosion in the iron?
2. I have the following products: Deoxit G5 Gold, and CRC QD Contact Cleaner. Ok to use on the corroded parts?
3. I have an unused battery which is orange in color. The label on the package says it is for use in the 7700. The No. on the package is 0040-001. The battery is probably 20 years old and had never been used. Should I try to use it?
I have an orange ISO TIP battery powered soldering iron that I was told by Radio Shack that the battery needed replaced and they couldn’t do that. I took it to Alied Battery shop and they replaced the battery and said that the battery probably needed charged before it would work. I took the iron home and put it on the charger and nothing. I dont know if they installed the correct battery or not, I took the cover off and they had soldered in the battery and I can not see any nomenclature on the battery, and I more than likely broke the small wire from the charging prong. The charger is putting out 2.7 volts as near as i can see on my voltmeter. I want to get this repaired and back in service. HELP PLEASE.
My 7700 quit working after a rebuild at your factory. The output from the charger reads .7 VDC. What should that voltage be to charge the new 2.4 VDC battery pack?