- Converts chemical energy to DC electrical energy
- Used in case of generator failure
- Voltage of lead acid battery fully charged is 2.2 V
- Capacity of a battery is the amount of amps that a fully charged battery can supply.
- Test to assess state of charge by comparing on load and off load battery volts.
- Made of lead peroxide & lead
- Electrolyte 30% sulphuric acid & 70% distilled water
- Can be charged using generator/alternator (source with a higher EMF)
- In storage, can be held on 'trickle' charge
+Lighter & more robust
+Sturdiness owing to it's metal casing
+Good storage capability + longer life
+Wider permissable temp range
- More expensive
- Lower voltage per cell
- Prone to thermal runaway
- +ve plates nickel hydroxide -ve plates cadmium hydroxide
- Electrolyte 70% distilled water 30% potassium hydroxide
Overcharging problem caausing electrolyte to boil, violent gassing, meltdown of plates and possible explosion.
- keeping charge rates within limits
- monitoring battery temp