Li-Ion batteries

Mainly specifications:

• Lithium-Ion batteries are half weight, lighter than equivalent capacity in Ni-Cd or Ni-Mh batteries.
• They are from 40% tp 50% smaller than Ni-Cd batteries and from 20% to 30% in Ni-Mh case.
• Fully friendly environment batteries.
• Metal lithium parts free. They are air shipments allowed.
• Low cost, long life with more than 500 charging / discharginbg cycles.
• 2-3 hours fast charge is acceptable with constant current / voltage method.

Charge

• Charger with CC/CV (Constant Current / Constant Voltage) feature is necessary. Constant current is applied up to 4,1 Volts or 4,2 Volts is reached. Then, battery voltage is held.
• Depending on battery model, never allow higher voltage than 4,1 Voltis or 4,2 Volts.
• Charging temperature range is from 0ºC to 45ºC.
• 90% of nominal capacity is reached if max. Charging current is 0,5C - 1,5C, with 70-120 minutes.
• If voltage is smaller than 3 Volts, 0,1C or lower charging current is necessary.
• Pole reversing charging protection must be applied.

Discharge

• If battery reaches less than 2,75 Voltios, it is discharged.
• Temperature discharging rate is 20ºC to 60ºC.
• Highest permanent discharging current must be less or equal to 1C.
• Avoid battery voltage less than 3 Volts during dicharging process.

Protection Devices

It is necessary to include protection devices to avoid critical values excess. IC’s manufactures offer specific models to protect battery life.

• Maximum Charging Voltage
• Minimum Charging Voltage
• Maximum Charging Current
• Maximum Discharging Current

Packing Batteries

When higher voltage is required, packing several battery cells is necessary. Cells assembling is arranged with electric soldering of Nickel tags. Also, it is necessary to introduce protection devices to check cells individually not for full battery pack. Lihium - Ion batteries are suitable for parallel connection because of individual protection required instead full battery pack control.