What is a use error failure?
Common use error failures would be over discharge, over charge, shorting, crash damage, over amperage, and use in salt water.
Over discharge is discharging any individual cell below its rated minimum voltage per cell. Most modern applications have cutoffs or warnings (set at 3.4V per cell or higher) that allow you plenty of time to stop use before over discharge can occur. Once a battery is over discharged it begins to lose capacity and capable performance. The further down it is discharged, the more apparent that deterioration is. If over discharge does occur, it is recommended that you discontinue use on that battery. Consult a friendly MaxAmps associate for guidance and assistance when this occurs.
Over charging is less common with today’s smart Lithium Charger models available. If you have the correct settings on the charger, it will not over charge a battery. There may be ways to bypass that setting in order to purposely over charge the battery in an effort to increase runtime or performance. That additional performance comes at the cost of cycle life though. MaxAmps strongly discourages charging above 4.2V for use as it is not safe and will severely limit the cycle life of a battery.
Shorting from mishandling or crash damage that deforms a cell is likely to cause an internal short which will cause failure. Shorting is the most likely scenario that you are to experience thermal runaway (fire). The likelihood of this is higher at higher states of charge. (i.e. full charge or over charged batteries are more likely to experience this if shorted.) Shorting is the completion of a power circuit when the positive and negative connections come together. This can happen if wire is damaged, plugs are damaged, or the battery is dented/punctured/damaged and those connections are able to connect, completing the circuit.
Over amperage during the use of a battery is when the amp rate causes the battery to build up heat beyond 140 degrees Fahrenheit/60 degrees Celsius in use or that the voltage under loads drops it below its rated minimum voltage range. While a battery may be able to maintain high amp draws for short periods, extended use at these rates will inevitably deteriorate a battery over time. This can be as little as 1 cycle on a battery if the amp rate is high enough. Swelling, excessive heat in/after use, venting, and melted heat shrink (protective coating of LiPo batteries) are all signs that this has occurred.
In addition, just because a cell is able to maintain a specific load, it doesn’t mean the components you have chosen are rated for that same load. While a MaxAmps 5200mAh battery may be capable of a 200A draw, an XT60 connector is not. This will cause excessive heat buildup, which will eventually reach and damage cells during use. For questions about proper wire/connector options, give us a call!
Although most lithium batteries are inherently water proof, salt water is a whole different beast. Salt water will actually render lithium inert so exposure to it has a high likely-hood of causing premature failure. If you are running in this environment, use a water-sealed battery box and connector system.