Ắc quy Nickel-Cadmium (Ni-Cd ChangHong)

Sealed Lead Acid

Nickel – Cadmium battery

Advantage

- Inexpensive and simple to manufacture – in term of cost per watt hours, the SLA is the least expensive

- Mature, reliable and well-understood technology  when used correctly, the SLA is durable and provides dependable service

- Low self-discharge – the self-discharge rate is among the lowest in rechargeable battery systems

- Low maintenance requirement – no money, no electrolyte to fill. Capable of high discharge rates.

- Fast and simple charge – even after prolonged storage

- High number of charge/discharge cycles – if properly maintained, the NiCd provides over 1000 charge/discharge cycles

- Good load performance – the NiCd allows recharging at low temperatures.

- Long self life – in any stage-of-charge

- Simple storage and transportation – most airfreight companies accept the NiCd without special conditions

- Good low temperature performance

- Forgiving if priced – the NiCd is one of the most rugged rechargeable batteries

- Economically price – the NiCd is the lowest cost battery in terms of cost per cycle

- Available in a wide range of sizes and performance options.

Disadvantage

- Cannot be stored in discharge condition

- Low energy density – poor weight-to-energy density limits use to stationary and wheeled applications

- Allows only a limited number of full discharge cycles – well suited for standby applications that require only occasional deep discharges

- Environmentally unfriendly – the electrolyte and the lead content can cause environmental damage

- Transportation restrictions on flooded lead acid – there are environmental concerns regarding spillage in case of an accident

- Thermal runaway can occur with improper charging

- The SLA has a relative low energy density compared with other rechargeable batteries, making it unsuitable for handled devices that demand compact size. In addition, performance at low temperatures is greatly reduced

- The SLA is rated at a 5-hour discharge or 0.2C. Some batteries are even rated at a slow 20 hour discharge. Longer discharge times produce higher capacity readings. The SLA performs well on high pulse currents. During these pulses, discharge rates well in excess of 1C can be drawn.

- In term of disposal, the SLA is less harmful than the NiCd batteries but the high lead content makes the SLA environmentally unfriendly. Ninety percent of lead acid-bases batteries are being recycled.

- Relative low energy density – compared with newer systems.

- Memory effect – the NiCd must periodically be exercised to prevent memory.

- Environmentally unfriendly – the NiCd contain toxic metal

- Some countries are limiting the use of the NiCd battery

- Has relatively high self-discharge – needs recharging after storage.