CHARGES
Different loading systems associated to the different technologies
1.- Chargers for accumulators and/or Ni-Cd and Ni-MH cells. Chargers of constant current.
2.- Chargers for MP lithium Ion accumulators and/or batteries.
3.-Cargadores para acumuladores y/o baterías de LITIO ION en formato pristmatico
1.- Chargers for accumulators and/or Ni-Cd and Ni-MH cells. Chargers of constant current.
The portable batteries can be charged at different rates. The applications are those, which determined the time of charge and the complexity of the charger. The rate of charge can extend from 30 minutes to 15/30 hours.
The standard charges are those between C/10 and C/20. Nevertheless, with the increasing use of portable appliances, there is a growing demand for charges to provide much faster charging rates up to 4C (15 minutes: ultra fast charge).
Thus, it is vital to designed chargers with ensure a secure operation without an overcharge in the batteries.
Most common charges are:
- Permanent charges: The charge is permanently kept within determined parameters. Currently pre-set between C/20 and C/30 .
- Standard charge: Selected in the CEI form most of the test. Charge of 16 hours at C/10 .
- Quick charge: It's the pre-set charge, in order to load the cells within three and six hours .
- Fast charge: It takes between one and two hours.
- Trickled charge: It is applied after the quick and fast charges. The rate can vary between C/20 and C/40. It is recommended to compensate the auto-discharge produced in the accumulators.
Main cut-off detection methods:
| Charge Time | Temperature Range | VR / VE / VRE | VSE | VT | VH (b) | GB / HB |
| Permanente | Ver datos debajo | Si | Si | Si | Aceptable (c) | Yes |
| Estandard 16 h | 0ºC a +50ºC | Timer | Timer | Timer | Timer | Timer |
| Acelerada 7-8 h | +5ºC a +50ºC | TimerTimer | TimerTimerTimer (8 hours) |
Timer
(8 hours) |
Timer | - |
| Acelerada 4-5 h | +5ºC a +50ºC | Timer o dT / dt |
Timer | dT / dt |
-ΔV | - |
| +5ºC a +35ºC | -ΔVo PKV | -ΔVo PKV | - | - | - | |
| Rápida 1 a 2h (a) | +10ºC a +40ºC +10ºC a +50ºC |
-ΔV
o PKV dT / dt |
-ΔVo PKV dT / dt |
- | -ΔV dT / dt, PKV |
- |
| (a) If C > 4.5Ah limited 2h - (b) Maximum recommended temperature limited at: +40ºC, -DV recommended (-5mV maximum per cell) - (c) With limited performances | ||||||
| Type of control | Performance | Graphic |
| Control by timer: | It sets a time of charge after which the charger cuts off the charge or changes over to trickle charge. |  |
| Control based on voltage detection | Cut off after the pre-set voltage has been reached. Not frequently used as it depends on technology, temperature, charging rate, etc.. |  |
| Cut off after the pre-set voltage has been reached. The charge is stopped when the charge voltage reaches its highest point. |  |
|
| Cut off by detection of negative variation of the charge voltage. The charge is cut off when the current of the charger detects a negative variation pre-set in the battery charge voltage. 10 mV/voltage drop for Ni/Cd and 5 m/voltage for Ni/MH batteries. |  |
|
| Control based on temperature: | Cut off by absolute temperature. The charge is stopped when the temperature reaches the pre-set levels , usually 45ª C. However, this method is not very accurate as it may result in an insufficient charge or an overcharging, depending on the environmental temperature conditions |  |
| Cut off by variation of the pre-set temperature. The charge is stopped when the positive variation of the temperature fluctuate from 0.5º C to 1ºC/min. It is one of the most recommended methods. |  |
2.- Chargers for MP lithium Ion accumulators and/or batteries.
The charging method for lithium ion accumulator is constant voltage and limited current. The accumulators incorporate a protective circuit that must be associated to the charger.
The nominal voltage must be 4.1V ± 0.04V/element. The current must be limited to 1C max.
The charging temperature must be from 0ºC to +50ºC
The SAFT MP batteries accept pulse charge for fast charge.
The end of charge detection can be done by time: 3 to 4 hours at 1C; 4 to 5 hours at 0.5C and 7 to 8 hours at 0.2C charge.
Main cut-off detection methods:
| Model | Charge Method | Charging Voltage | Charging Current | Operating Temperature | End of Charge Detection | |
| Low Current | Timer | |||||
| MP144350 | Constant Current/ Constant Voltage (CCCV) | 4.1V ±0.04V per cell |
1 C máx. | Charge 0ºC a +50ºC Discharge -30ºC a +60ºC |
30 mA | To be set as a function of the charging current: 1C » 3 a 4 h 0.5C » 4 a 5 h 0.2C » 7 a 8 h |
| MP174865 | 70 mA | |||||
| MP176065 | 100 mA | |||||
| Operation | Graphic |
| Typical of this type of charge is the low current method, which, once the voltage reaches the maximum pre-set value, the current decreases up to very low rates. |  |
3.-Cargadores para acumuladores y/o baterías de LITIO ION en formato pristmatico
Las baterías realizadas con acumuladores de Litio ion deben ser cargadas siempre mediante carga a tensión constante y corriente limitada.
La tensión de carga de estas baterías debe ser de 4.2V + - (con el signo adecuado) 0.05V. La intensidad de carga máxima será de 1.0C
El sistema de corte de carga puede emplearse el de control por temporizador o el de mínima corriente de carga. El método de control por temporizador dependerá del régimen de carga.
El método de mínima corriente de carga dependerá del tipo de batería y del estado de carga final que se quiera alcanzar.
Temperatura de carga: 0ºC a +45ºC
Temperatura de descarga: -20ºC a +60ºC
El corte de descarga debe ser realizado a 2.75V/acumulador.
Sistema de Selección de un Acumulador para una Utilización
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