Yes but very carefully and very quickly. Soldering Li-Ion batteries like 18650 and 21700cells puts a lot of excess heat into them during the soldering process. This extra heat does a small amount of damage to wh.
To solder lithium batteries properly, you need a very high-power soldering iron. This may seem paradoxical at first, but a high-powered soldering iron is able to perform soldering operations much quicker, resulting in less overall heat being imparted into the cells from the hot solder.
Can a soldering iron contact a battery?
Do not allow the soldering iron to make direct contact with the bodies of the batteries. Proceed with the sol-dering quickly within 5 seconds while maintaining the iron tip temperature at about 350°C, and do not allow the temperature of the battery bodies to exceed 85°C. (Heat resistance BR type is 125°C)
Can You solder 18650 batteries?
First things first – yes, you can solder 18650 batteries. The key is using a high-powered soldering iron that gets the job done quickly. This minimizes excess heat that could damage the batteries. However, most battery experts agree that soldering should only be done as a last resort. Spot welding 18650 cells is a much better option.
What happens if you solder a lithium battery?
The problem with soldering lithium batteries is that the heat from the soldering process damages the cells to some degree. Not only does it damage the cells, but it damages the cells to an inconsistent degree in most cases. This can cause the battery pack to come out of balance later on.
To solder a lithium battery, you're going to need at least 100 watts of power at the tip. Having triple-digit watts at your disposal is required to be able to get in there, form an excellent connection, and get you- quick. It may seem counter-intuitive, but the best soldering iron-to-solder lithium-ion batteries is going to be the hottest one.
How do you solder a battery?
Use a 100W+ soldering iron. Higher wattage means faster heat transfer. Spend as little time as possible in contact with each battery terminal. Work quickly. Get your solder joints completed in 2-3 seconds max. The longer your iron touches the cell, the more heat soaks in. Apply plenty of flux.