Since the unit of the C-rate is typically implied, some care is required when using it to avoid confusing it with the battery's capacity to store a charge, which in the SI has unit coulomb with unit symbol C. Likewise, for the same battery a charge current of 250 mA corresponds to a C-rate of C/2, meaning that this current will increase the state of charge of this battery by 50% in one hour. The C-rate is never negative, so whether it describes a charging or discharging process depends on the context.įor example, for a battery with a capacity of 500 mAh, a discharge rate of 5000 mA (i.e., 5 A) corresponds to a C-rate of 10C, meaning that such a current can discharge 10 such batteries in one hour. While rarely stated explicitly, the unit of the C-rate is h −1, equivalent to stating the battery's capacity to store an electrical charge in unit hour times current in the same unit as the charge or discharge current. The C-rate is defined as the charge or discharge current divided by the battery's capacity to store an electrical charge.
For public access, installation of such chargers and the distribution support for them is an issue in the proposed adoption of electric cars.Ĭharge and discharge rates are often given as C or C-rate, which is a measure of the rate at which a battery is charged or discharged relative to its capacity. Electric vehicles ideally need high-rate chargers. Such batteries require active monitoring of the battery to protect it from overcharging. High-rate chargers may restore most capacity much faster, but high rate chargers can be more than some battery types can tolerate. Slow battery chargers may take several hours to complete a charge. Lithium-ion batteries cannot handle indefinite trickle charging. Some battery types cannot tolerate trickle charging attempts to do so may result in damage. Ī trickle charger provides a relatively small amount of current, only enough to counteract self-discharge of a battery that is idle for a long time. The charger may have temperature or voltage sensing circuits and a microprocessor controller to safely adjust the charging current and voltage, determine the state of charge, and cut off at the end of charge.Ĭhargers may elevate the output voltage proportionally with current to compensate for impedance in the wires. Other battery types cannot withstand over-charging, becoming damaged (reduced capacity, reduced lifetime), over heating or even exploding. Other battery types use a timer to cut off when charging should be complete. Simple chargers of this type must be manually disconnected at the end of the charge cycle.
Some battery types have high tolerance for overcharging (i.e., continued charging after the battery has been fully charged) and can be recharged by connection to a constant voltage source or a constant current source, depending on battery type. The charging protocol (how much voltage or current for how long, and what to do when charging is complete) depends on the size and type of the battery being charged. My guess is the outlet will switch itself off and u have to come back and start the process again.For other senses of this term, see AC adapter.Ī battery charger, or recharger, is a device that stores energy in a battery by running an electric current through it. The one thing I cannot attest to is what happens if there is a power outage for more than 5-15 minutes or so. And u can leave it that way for as long as u like, and the outlet will stay alive for maintaining. And the CTek will have ur battery fully charged and ready to go in typically 10-24 hours, depending on how bad it was when starting the charging and charger processes. The outlet will not switch off as long as there is no extended power outage. (for modern Porsche AGM batteries) and it will "maintain" it as long as u like. Then immediately plug in ur CTek in the Winter (snowflake) mode. Here's what to do: turn on the ignition and make sure the dash lights up, but no need to actually start it. The CTek 4.3 never fails to do the job on a Porsche if connected at least over night, but must be switched to snowflake mode (winter mode).Ībout the outlets in the ashtray and console - If you just walk away and come back later, they will switch off and stay off when u plug the CTek. I now have enough experience with a V8 Cayenne, 981 Cayman S and Macan Turbo to finally talk about what I found.