This was my first time really soldering, so it is definitely not pretty, but it fixed the board and I am quite proud of what I took away from the project! I have had a little experience with soldering in the past, but it was way back in middle school, so it really was not of much help. I would consider myself tech minded but have little experience actually fixing/working on electronics, so if I missed anything or need to clarify any points, please let me know in the comments!

     We had a Parallel Charge Board for JST-XH and T-Plug lying around for use in the shop which had been damaged in a stress test with a new charger. It worked fine for balancing on the left half of the board, but would not balance larger than a 3S on the other side due to a few burnt traces. With a simple circuit design and ease of assembly, the board was a perfect starting point for learning to solder.


     When servicing electronics it is best to begin by cleaning the area of interest. This not only allows a better view of what is actually causing the issue, but also prepares your work area for soldering later. I found two traces clearly had burnt and actually started to peel off of the board, so I clipped off the burnt tracings back to a point where I knew I could solder from the other side. A third trace was exposed but appeared intact, not broken as far as I could tell, so I left it until I could test it later and make sure it was working properly.

     As the burnt traces were too large to bridge with solder alone, I decided to use some extra wire we had lying around the shop to bridge the gap. I used 22 gauge wires; however any size that will handle the applied load will work. In order to get to the back of the board, I removed the board’s housing by unscrewing the four screws on the back.

     This exposes the pins underneath the board, providing a great spot to solder to. I began by figuring out where my missing traces were located on the reverse side. Using my multimeter on its resistance/ohmmeter setting, to determine which pins still had an intact trace, I began testing the pins until I determined which needed to be joined. This was fairly easy, as the board has visible traces and the balance ports are neatly arranged in line.

     Once I had determined which of the pins would be soldered to, I began the ‘tinning’ process to prepare the wire and pins to be soldered. Tinning is simply the act of applying a little bit of solder to the points that you will be soldering together. This provides a better surface to solder to, and promotes better contact between the joined pieces.

     In order to begin, I attached the smallest soldering iron tip available in order to get in between the JST-XH spaced pins on the board. Careful to only touch the pin I was soldering to with the iron, I held it on the far side of where I wanted the solder placed. As the pin heated up, I held the solder to where I wanted to tin, allowing the iron on the opposite side to heat the pin to the temperature necessary to melt the solder. Applying the solder in this manner is important, as it allows for the solder to better bond to the pin’s surface. If you simply melt the solder with the iron and drip the hot solder onto the cold pins surface, you would not receive this same bond we are after.

     Once that is done, the soldering process begins. As I was soldering two wires to the board, I wanted to make sure not only that I had enough room between them that they did not come into contact, but also that there would be enough room to work around them with the soldering iron tip. In order to do this, I positioned the wires to the outside of the pins, making sure good contact was made between the wire and pin to allow the heat to flow between the two. Maintaining that contact, I held my soldering iron to the pin until I could see the solder from tinning begin to melt. At this point, I touched the solder from the spool to the heated pin and wire, making sure a good amount of solder wicked between the two. I was careful not to apply too much, as I did not want to make contact with the other pin. I repeated this process on the other end, after allowing enough time for the jumper wire to cool in between soldering. I then repeated this entire process for the second gap that needed bridging.

     After finishing soldering, I checked the connections one last time with my ohmmeter to make sure I had properly completed the traces. I reassembled the board and hooked it up to my iCharger to make sure it was working properly. Using a 6S Spyder battery, I tested the balance ports on right hand side to make sure the charger would properly read cell voltages. I was glad when it read the correct voltages on the bottom most 6S port, as I knew this would mean the correct connections were all now complete!

     I picked up this project to teach myself a little bit about the process of soldering, and also walked away with a better understanding of the parallel charge board. The teardown and reassembly of any device you might be working on will teach you at least a little more about how the devices work. I can’t wait for the next device that fails and needs repair to come my way. I will try to remain as open to trying new things, and if I do, will surely write another entry about it to let you guys know how it goes!