Calculate what you need first and then decide how much capacity you need to cater for and what to purchase.
Plenty of people go and buy an Ellies or Mecer inverter/charger with a single 105Ah lead acid battery and end up disappointed when it doesn't power their 300W gaming PC, 200W sound system, 300W plasma TV, LED lights, etc. for more than 2 hours.
They are even more disappointed when their R2500 lead acid battery dies after 6 to 12 months of use due to it being deeply discharged. 105Ah 12V lead acid batteries cost around R2000 to R3000 each.
The rule of thumb is do not discharge a lead acid based battery below 50% DoD (Depth-of-Discharge) if you want it to last. If you use lead acid batteries you need to have double the capacity than your equipment requires for a period of time.
Example:
1. Add up the power requirement of all your equipment in Watts. Let's say 200 Watts.
2. Multiply by the hours it needs to run for which gives Watt-hours (Wh). 200W * 4 hours = 800Wh
3. Take the battery voltage and multiply it by the Ah rating to get Watt-hours. e.g. 12V * 105Ah = 1260Wh
4. If you're using lead acid batteries you shouldn't discharge below 50% of capacity if you want them to last so that gives you a maximum of 1260Wh / 2 = 630Wh. This means you can run a 200W load for a maximum of 3.15 hours (630Wh / 200W = 3.15 hours) before reaching 50% DoD.
Plenty of people go and buy an Ellies or Mecer inverter/charger with a single 105Ah lead acid battery and end up disappointed when it doesn't power their 300W gaming PC, 200W sound system, 300W plasma TV, LED lights, etc. for more than 2 hours.
They are even more disappointed when their R2500 lead acid battery dies after 6 to 12 months of use due to it being deeply discharged. 105Ah 12V lead acid batteries cost around R2000 to R3000 each.
The rule of thumb is do not discharge a lead acid based battery below 50% DoD (Depth-of-Discharge) if you want it to last. If you use lead acid batteries you need to have double the capacity than your equipment requires for a period of time.
Example:
1. Add up the power requirement of all your equipment in Watts. Let's say 200 Watts.
2. Multiply by the hours it needs to run for which gives Watt-hours (Wh). 200W * 4 hours = 800Wh
3. Take the battery voltage and multiply it by the Ah rating to get Watt-hours. e.g. 12V * 105Ah = 1260Wh
4. If you're using lead acid batteries you shouldn't discharge below 50% of capacity if you want them to last so that gives you a maximum of 1260Wh / 2 = 630Wh. This means you can run a 200W load for a maximum of 3.15 hours (630Wh / 200W = 3.15 hours) before reaching 50% DoD.