High temperature button cells

• Friendly enviromental batteries.
• High energy density.
• Low cost, long life with more than 500 charging - discharging cycles.
• Low internal resistance with excellent discharging rate.
• Recharging is allowed even after long storage period.
• 1-2 hours fast charge is allowed.
• Wide working temperature range. They are special series for over 70ºC conditions

Charge

• Current, time, temperature and other factors, affect Ni-Mh battery charging curves.
• These batteries must be charged from 0ºC to 45ºC temperature conditions but 0ºC - 30 ºC range is more efficient.
• Inversing polarity is not allowed during charging process.
• Numerous overcharguings will damage battery efficiency.
• One reliable charging system is “Trickle charge” which is arranged with 0,03C to 0,05 C currency values. Charging time must be limited up to 22-32 hours.
• If fast charging is used, it is absolutely necessary to use an electronic system to detect negative voltage increasing (-V). Never allow charging currency over 1C. Battery negative voltage increasing (-V), is a special Ni-Mh batteries feature to detect battery is full. Let’s explain this characteristic: If current is applied to empty battery, voltage is increasing value solwly during charging process. However, when battery reaches full condition, voltage starts to be lower and temperature is higher. This is right point to stop charging current.

Discharge

• Discharging temperature range is from 10ºC to 50ºC.
• Discharging current rate could affect battery capacity. Best efficiency is reached with discharging rate of 0,1C - 2C. High discharging current will produce an important temperature increasing.
• Battery will be damaged if overdischarging. Never hold battery connected under empty condition.
• If battery voltage is below 1,0 Volts, it is empty.

Other Specifications

• These batteries can be long storaged in dry conditions with 10ºC - 30 ºC temperature.
• After long storaging, first chargings will reach lower capacity than nominal value specified.
• Battery life is more than 500 cycles if charging - discharging is arranged under roght conditions. Different processing conditions will atempt battery life, losing cycles life.
• Do not solder directly on battery contacts, heating excess will damage chemical and mechanical internal parts of the battery. Nickel or silver-nickel tags are suitable to be soldered on battery contacts with electric soldering process.
• Avoid shortcircuit in Ni-Mh batteries because extreme pressure will produce high heating.

Battery Packing

When higher voltage is required, packing several battery cells is necessary. Cells asembling is arranged with electric soldering of Nickel tags. Also, it is usual to introduce protection devices as follows:

• Polyswitch. This device is rated at specified nominal currency. Over this currency, internal resistor is high to stop currency passing. When Device gets colder, internal resistor is close to 0.
• NTC. Electronic component with variable resistor depending on temperature rate. It is used to check battery temperature.
• Thermostate. This device cuts off voltage sourcing when temperature excess is higher than value rated. When device gets colder, it resets itself.
• Thermo-fuse. Safety device which cuts off voltage but without resetable function.