Safety Features
When our design engineers created the Viper battery, they realized that storing such a large amount of energy would require an even greater commitment to product safety. You might say they held true to the old adage that "with great power comes great responsibility." We are proud to submit the following outline to demonstrate how each of our batteries is equipped with numerous levels of protection.
We begin with the self-switching PTF (poly-temp fuse) installed in the canister of each and every one of our individual lithium-ion cells. This device allows energy to pass freely from cell to cell or blocks its passage if the internal temperature exceeds the PTF’s pre-set value. As we use only the highest quality temp fuses, they are accurate to within 1% of this value. When the cell’s operating temperature returns to normal the PTF re-sets itself and resumes allowing the energy to pass freely. The individual cells are then welded into a pack using the broadest and heaviest connecting tab stock allowable. This serves a two-fold purpose. The broader the tab stock the wider the area is for the energy to flow. This helps to eliminate potential heat buildup.
The heavier tab stock fortifies the strength of the battery pack, making it more solid. The more solid a pack can be made, the less likely it is that a broken weld will occur, reducing the risk of short circuits. A compartment temperature sensor is then installed. This sensor guards against inappropriate battery usage in the event the internal temperature of the battery case is elevated to an unsafe level.
Once the battery pack is secured, the Safety First Circuitry is attached. The Safety First Circuit Board is the Viper's primary safety system and is responsible for the battery's BTC interface capability. While in use, the board provides the battery with triple redundant protection.
First, the battery is protected against over current. This means the battery will shut down should it be exposed to a charge current greater than 5 Ah or a discharge rate greater than 10 Ah.
Second, it is protected from over voltage. Again, the battery will automatically decline to accept any voltage input higher than 16.8V, the cell manufacturer’s recommended charging voltage for a pack this size.
The third fail-safe prevents over heating. As in the first two scenarios, the battery will not function if its operating temperature exceeds the cell manufacturer’s suggested limit.
Each one of these three safety circuits is supported by two back-up circuits in case the first fails. Therefore, you have three safeguards: one against over current, three against over voltage, and three against overheating- a total of nine in all. Breaching this much security would require opening the case and shunting past the Safety First Circuitry.
Another safety factor is the battery housing or case design. The case is composed of a high impact-resistant plastic, capable of easily passing most standard “drop" tests. The interior is specially molded so that the battery pack fits snuggly, greatly reducing wasted space or “flop" room. This lessens the possibility of a weld coming loose, causing a short circuit. We have recessed the contact points to reduce the opportunity for accidental short circuiting of the positive and negative terminals. Again, it is possible, but it would have to be done intentionally. Lastly, only two of the four contact holes are active, which eliminates the possibility of the Viper being charged on anything other than one of our world wise chargers.
It should be apparent by now that we at SBI take safety extremely seriously. We much prefer you focus on the benefits of switching to the lightweight, increased run-time lithium-ion technology, and leave the "what ifs" to us. Please do not hesitate to call if you have any questions or comments regarding our products. Our friendly, knowledgeable sales staff would love to hear from you!