Li-Po battery with broken off tabs - fix - Page 1
Forum section: electronics / beginners

author: BinaryBits
author_rank: Contributor
timestamp: September 01, 2022, 08:57:41 am
content: So I have a 3.7V, 6000mAh Li-Po, which has had its tabs broken off. I would like to use the battery if possible.I don't know if its such a smart idea to solder in such close proximity to the battery. I also just recently sold my spot welder.Right now the battery is at around 3.85V.So is there some way to safely attach wires to these small "tabs" that are still on the battery? Does one dare to solder to these "tabs"?

author: RubyRhod
author_rank: Contributor
timestamp: September 01, 2022, 09:18:09 am
content: I personally would not have a problem attempting to solder to the tabs but I would use an iron with the smallest tip available and avoid a Weller D550 type of soldering gun for obvious reasons. Good luck!

author: strawberry
author_rank: Super Contributor
timestamp: September 01, 2022, 09:36:33 am
content: one tab is copper other tab aluminium

author: wraper
author_rank: Unknown
timestamp: September 01, 2022, 09:51:42 am
content: Quote from: RubyRhod on September 01, 2022, 09:18:09 amUsing smallest tip is the worst thing you could do. With large tip you can do the job fast and let it cool. With small tip you will need to apply heat for unreasonably long time, thus battery may get overheated.

author: jpanhalt
author_rank: Super Contributor
timestamp: September 01, 2022, 10:00:44 am
content: There are a few non-solder approaches I would consider:1) Find a battery holder like for 9V batteries with the right spacing (image attached). Bend the tabs one last time and wedge the sell against the contacts. That's similar to how my cellphone battery is installed. Keystone has a large variety of hardware for electronics:https://www.keyelco.com/category.cfm/keyelco/Battery-Coin-Cell-Holders-Contacts-Clips/id/404You could make your own holder.2) Small alligator clips.3) Tight fitting female blade connectors (see Keystone). May be difficult to install.4) Similar to #3 but uses a screw clamp.

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 01, 2022, 01:48:40 pm
content: Quote from: BinaryBits on September 01, 2022, 08:57:41 ami've done several times to replace car jumper kit's battery lipo 4S or drones, to unsolder the original wire and soldered in the car jumper wire/adapter. the original wire was soldered from factory, not tabbed. so whats the odd? as more experienced guy here pointed out, use larger tip adequate power solder iron so you can do the job quickly. we need local heating very quickly, not risk heat spreading to battery internal chemical by using small tip/wattage iron for longer heat transfer duration. not just that, i sometime split/separate damaged cell from good cells, but be careful not to deform them too much, and be ready with an open space none combustible and no risk of fire spreading, so you can throw the burning cells to that space in case something wrong like in youtubes happened. ymmv.

author: amyk
author_rank: Super Contributor
timestamp: September 02, 2022, 04:18:54 am
content: Quote from: wraper on September 01, 2022, 09:51:42 amYes, you want the biggest hottest tip you can find. Ideally you only need to touch for a fraction of a second to complete the soldering. The same reason these are usually spot-welded, as of course the temperature of welding is much higher than soldering, but it also takes far less time.

author: --Oz--
author_rank: Regular Contributor
timestamp: September 02, 2022, 05:47:02 am
content: I have repaired many lipo batteries, usually one cell gets hammered in a crash, so I remove it and make a 3s out of a 4s, or fix multiple packs with that one pack.Having repaired many lipos, some will just accept solder and some will not, I found "solder-it" flux and it works wonders on the ones that will not accept (wet) solder. As soon as your done with the solder joint wipe the tip asap as it can hurt the tip I have found. Of course since its a flux, flow in the solder.https://www.amazon.com/Solder-SILVER-SOLDER-PASTE-piece/dp/B001S32FUG/ref=asc_df_B001S32FUG/?tag=hyprod-20&linkCode=df0&hvadid=563711343082&hvpos=&hvnetw=g&hvrand=637745868006937247&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031536&hvtargid=pla-1601931601904&psc=1One year I flew just over 10K flights, so I have crashed a bit, yea, they are 90 second flights, but thats 250 hours of flight with high action. My quad can spin 7.5 revs/sec, here is my style of flying.

author: RubyRhod
author_rank: Contributor
timestamp: September 13, 2022, 02:04:38 pm
content: Quote from: amyk on September 02, 2022, 04:18:54 amYour point is well taken but, with my temperature controlled station, I can make a small tip hot enough to do the job successfully.