AC ADAPTER SAFETY
If you have no power after you receive your new ac adapter
Check your dc jack to see if it moves. If it does it may be cracked.
If you have to wiggle the ac adapter to get power then your dc jack may have a crack in it or it is worn out.
If you see electrical arching when you plug in the ac adapter the dc jack it is cracked
The dc jack is the part on the device. The ac adapter plugs into.
If the new ac adapter gets very hot discontinue use.
You may have a jack or circuit problem or purchased an under rated ac adapter for your laptop.
Stop use of the device and ac adapter. Have a technician inspect it.
Caution: Replace ac adapter with the same voltage and amps rating. The rating can be found on the label of the device.
Example: Device needs 19V 3A you purchased 19V 2A this is not good it is under powered and a fire hazard.
Caution: Do not use an ac adapter with frayed or exposed wires.
Caution: Fire hazard or chemical hazard if mistreated. Do not disassemble.
Caution: Dispose of properly consult your local regulations or waste disposal provider.
Caution: Do not incinerate or expose to temperatures above 140 degrees.
Caution: Dispose of used ac adapter properly and promptly please recycle.
Caution: Keep away from children and pets.
Caution: Do not lay Ac Adapter on linens, Towels, bedspreads it will cause the Ac Adapter to over heat and become very hot.
Caution: Ac Adapters can become very hot and could cause burns or fire hazards please use properly.
BATTERY SAFETY
Caution: Danger of explosion if battery is incorrectly placed.
Caution: Replace battery with the same voltage and amps rating
Caution: Fire or chemical hazard if mistreated. Do not disassemble.
Caution: Do not handle damaged or leaking lithium-ion batteries.
Caution: Dispose of properly consult your local regulations or waste disposal provider.
Caution: Do not incinerate or expose to temperatures above 140 degrees
Caution: Dispose of used battery properly and promptly please recycle
Caution: Keep away from Children and pets.
What is Capacity
The quantity of electricity that can be obtained from a battery in one cycle from full charge to full discharge when the battery is discharged under conditions of rated current level and ambient temperature within the predetermined range. Generally, capacity is expressed in units of mAh (milliampere-hour).
What is Nominal Capacity
The standard capacity designated by a battery manufacturer to identify a particular cell model.
What is Nominal Voltage
The standard voltage used to express the capacity of a particular battery model. It is generally equal to its electromotive force or its approximate voltage during normal operation. Typical Values:
• 1.2 volts per cell for NiCd and NiMH
• 3.6 or 3.7 volts per cell for Lithium Ion or Lithium Polymer
• 3 volts per cell for lithium primary
• 2 volts per cell for sealed lead acid
• 1.5 volts per cell for alkaline and carbon zinc
What is discharge rate
The discharge rate is the rate at which current is removed from a battery. When a battery is discharged at a current level "i", for a period until the end discharge voltage is '"h", the discharge is referred to as the h-hour rate discharge, while "i" is known as the h-hour rate discharge current. For practical use, nominal capacity is used as standard.
What is End-Voltage
The voltage that indicates the end limit of discharge. This voltage is almost equivalent to limitation of practical use. Typical values:
• 1.0 volt per cell for NiCd and NiMH
• 1.75 volts per cell for sealed lead acid
• 2.75 volts per cell for lithium ion and lithium polymer
• 2.0 volts per cell for primary lithium
• 0.9 volts per cell for alkaline and carbon zinc
what is Open circuit voltage
The voltage between terminals of a battery without any load.
What is Operating voltage
The voltage between terminals when a battery is subjected to a load. Usually expressed by the voltage of the battery at 50% discharge point.
What is Polarity Reversal
Reversing of polarity of the terminals of a small-capacity cell in a multi-cell battery due to overdischarge.
What is a Positive Electrode.
The electrode which has a positive potential. Electric current from this electrode flows in the external circuit during discharge.
What is a Negative Electrode.
The plate which has an electrical potential lower than that of the other plate during normal cell operation. Electric current from the external circuit flows into the cell at the negative electrode during discharge. Also called minus electrode.
What is a Self-Discharge.
A decrease in battery capacity which occurs without any current flow to an external circuit. Typical values:
• 1% per day for NiCd
• 2% per day for NiMH
• ~0% per day for Lithium Ion and Lithium Polymer
What is a Short Circuit.
Directly connecting the positive electrode (terminal) to the negative electrode (terminal) of the battery.
What is a Thermistor
A circuit element with a negative temperature coefficient. It is built into batteries and used to detect ambient temperature or battery temperature. A battery charger may use this device to properly charge a battery.
What is C-rate?
The charge and discharge current of a battery is measured in C-rate. Most portable batteries are rated at 1C. This means that a 1000mAh battery would provide 1000mA for one hour if discharged at 1C rate. The same battery discharged at 0.5C would provide 500mA for two hours. At 2C, the 1000mAh battery would deliver 2000mA for 30 minutes. 1C is often referred to as a one-hour discharge; a 0.5C would be a two-hour, and a 0.1C a 10-hour discharge.
The capacity of a battery is commonly measured with a battery analyzer. If the analyzer's capacity readout is displayed in percentage of the nominal rating, 100% is shown if a 1000mAh battery can provide this current for one hour. If the battery only lasts for 30 minutes before cut-off, 50% is indicated. A new battery sometimes provides more than 100% capacity.
When discharging a battery with a battery analyzer that allows the setting of different discharge C-rates, a higher capacity reading is observed if the battery is discharged at a lower C-rate and vice versa. By discharging the 1000mAh battery at 2C, or 2000mA, the analyzer is scaled to derive the full capacity in 30 minutes.
Theoretically, the capacity reading should be the same as with a slower discharge, since the identical amount of energy is dispensed, only over a shorter time. Due to internal energy losses and a voltage drop that causes the battery to reach the low-end voltage cut-off sooner, the capacity reading may be lowered to 95%. Discharging the same battery at 0.5C, or 500mA over two hours may increase the capacity reading to about 105%. The discrepancy in capacity readings with different C-rates is related to the internal resistance of the battery.
One battery that does not perform well at a 1C discharge rate is the portable sealed lead-acid. To obtain a reasonably good capacity reading, manufacturers commonly rate these batteries at 0.05C or 20 hour discharge. Even at this slow discharge rate, a 100% capacity is hard to attain.
To compensate for different readings at various discharge currents, manufacturers offer a capacity offset. Applying the offset to correct the capacity readout does not improve battery performance; it merely adjusts the capacity calculation if discharged at a higher or lower C-rate than specified.
Lithium-ion/polymer batteries are electronically protected against high load currents. Depending on battery type, the discharge is limited to between 1C and 2C. This protection makes the lithium ion unsuitable for biomedical equipment and power tools demanding high inrush currents.
How to prolong lithium-based batteries
Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one.
Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.)
Short battery life in a laptop is mainly caused by heat rather than charge/discharge patterns.Although memory-free, apply a deliberate full discharge once every 30 charges to calibrate batteries with fuel gauge. Running down the battery in the equipment does this.
If ignored, the fuel gauge will become increasingly less accurate. The battery life will not be affected.
Keep the lithium-ion battery cool. Avoid a hot car.
For prolonged storage, keep the battery at a 40% charge level. Consider removing the battery from a laptop when running on fixed power. (Some laptop manufacturers are concerned about dust and moisture accumulating inside the battery casing.)
Avoid purchasing spare lithium-ion batteries for later use. Observe manufacturing date. Do not buy old stock, even if sold at clearance prices.
How to store batteries
Keep batteries in a cool and dry storage area. Do not fully charge lithium and nickel-based batteries before storage. Keep them partially charged and apply a full charge before use. Store lithium-ion at about 40% state-of-charge (3.75-3.80V/cell open terminal). Lead-acid batteries must be stored fully charged.
* Do not store lithium-ion fully depleted. If empty, charge for about 30 minutes before storage. Self-discharge on a depleted battery may cause the protection circuit to trip, preventing a recharge.
Do not stockpile lithium-ion batteries; avoid buying dated stock, even if offered at a reduced price. Observe the manufacturing date, if available.
Never leave a nickel-based battery sitting on a charger for more than a few days.
Prolonged trickle charge causes crystalline formation (memory). 2.
