1. General type of batteries, also known as car batteries

2. Need water to maintain

3. Life expectancy: 1-3 years

1. Exhaust pipes shall be provided at resettlement sites in order to avoid danger as hydrogen will be produced when discharging.

2. Its acidic electrolyte will corrode metal.

3. Water is frequently needed for maintenance.

4. Low price.

lead-acid maintenance-free batteries

1. New type of batteries

2. No need of water

3. Life expectancy: 5-7 years in general

1. Sealed battery that will not produce any harmful gases when charging..

2. Easy to place, and unnecessary to consider the ventilation problem of resettlement sites.

3. Maintenance free.

4. High discharging rate and stable characteristics.

5. Relatively high price.

nickel-cadmium batteries

1. Advanced batteries for special occasions and equipment

2. Need water

3. Life expectancy: 20-40 years

1. No harmful gases will be produced when charging and discharging as water is the medium.

2. Water is needed for maintenance at fixed times although water loss rate is low.

3. The best discharging characteristics.

4. Can be placed in any harsh environment.

5. Very high price.

Taking the load conditions, using environment, service life, cost and other factors into account, people usually choose maintenance-free lead-acid batteries. Users shouldn’t choose bad batteries on the cheap, because they will affect the reliability of the overall system, and may result in greater losses.