Everything You Need to Know About Tesla Cells
Are they dangerous?
Nope! In fact, Lithium Ion 18650 Tesla Cells cells are much safer than most standard cells sold by Panasonic, HP, Sanyo, and other common Li-Ion distributors. The key reason for their safety is that Tesla batteries are put to use in automobiles. For this reason, they undergo greater safety protocols than most other Lithium Ion cells, most of which are intended for laptops. When Tesla started constructing their Roadster model, their goal was to produce a battery with a very low defect ratio. The result is a battery that has a defect ratio of 1:10,000,000. Very few 18650 batteries can even come close to this standard. Additionally, the battery can withstand higher Amp outputs with minimal heating. When we compared NCR18650’s to a Tesla battery at 60% amp draw, the Tesla cell remained at room temperature while the NCR18650 reached 90*F. Even at 8 Amps draw, the Tesla battery remained well below 85*F.
This is not to say that Tesla batteries are completely exempt from danger. While Tesla cells are more durable than standard Lithium Ions, it is important that you care for Tesla cells like any other battery. Make sure to to follow the following precautions:
1. DON’T SHORT CIRCUIT TESLA CELLS
This should be fairly self-explainatory. Yet, many people make the mistake of putting 18650’s in their pockets with loose metal and change. This risks shorting the cell since the positive and negative anodes are so close together.
Anything conductive (a coin, ring…etc) could easily cross the 5mm gap and cause a short circuit. In order to prevent this, our Tesla 18650’s have a thin wafer underneath the heat shrink to protect the contact distance. Yet, it’s still important to make sure your Tesla batteries aren’t stored with loose change and small pieces of metal.
2. DON’T OVER-DISCHARGE TESLA CELLS
While Tesla cells can tolerate more amp draw then Panasonic cells, it’s important to keep the amp draw per cell below 10A. However, a 15A bust charge for 15 seconds is acceptable. Generally, if you’re running a 18650 near its max discharge rate, you will want to ensure that there is proper airflow to cool the cell when it gets hot. For Tesla 18650’s, excessive heating tends to occur over 8A discharge. Even still, in our experimental runs, the Tesla cell only began to come hot after running at 10A for 60 seconds.
What can they be used for?
Tesla 18650’s can be used in a wide variety of appliances that most Panasonic or Sanyo cells can’t be used in. These include higher Amp draw appliances like Vape setups (70 Watts or below) and high-power tactical flashlights. While NCR18650’s can run in some devices at certain amp draws, the concern is the amount of internal heating inside the cells when it supplies an Amp draw near its max output. For panasonic cells, this isn’t good as it decreases the operating life with respect to the capacity loss curve. Since the capacity loss in Tesla cells is so small, you can still get a long lifespan out of each cell, even if the cells are ran at high amp draw.
The cells were tested with low Amp output flashlights (right) and high amp tactical flashlights (left).
When compared to the batteries most commonly used with these flashlight brands, the flashlights on average lasted 20% longer with the tesla cells. Additionally, the Tesla cells didn’t overheat. Overheating cells in flashlights is a common issue, even with less powerful flashlights like the Anker flashlight (left). Since the cells are in a closed space, there’s no ventilation to dissipate the heat. This leads to a much shorter cell life. The internal temperature of the flashlights we tested regularly exceeded 100 degrees. With the Tesla cells, the internal temperature rarely exceeded 80 degrees. Not only is this good for the flashlight, but it prevents the cell from overheating and failing.
Tesla cells can also be used for some vapes, assuming the max amp discharge is at 8A for safety. This depends on the the arrangement of the batteries in your vape (series or parallel). Check out this vape calculator to calculate the current, ohms, voltage, or wattage, depending on what values you have.
Most UAVs can also be powered by Tesla cells. Standard UAVs offered by companies like parrot have a low enough Amperage draw such that their Lithium Polymer batteries can be swapped with Lithium Ion cells. This greatly extends their lifetime since the Tesla cells have twice the amount of energy density as the Lithium Polymer cells. We will be making several videos soon detailing the various UAVs which can benefit from this battery swap.