Transistorgrab

This article takes a look on the costs of batteries compared to accumulators and additional chargers.

Energie costs

Batteries are one of the most expensive energie sources.
Lets make a calculation:

• Battery: Alkaline, size: AA
• Voltage: U = 1.5V
• Capacity: K ≈ 2Ah

For one battery the stored energy is:

E = U ⋅ K = 1.5V ⋅ 2Ah = 3Wh

To get one kilowatthour energy out of batteries you need:

If one battery is 1,00 € then per kilowatt hour you pay:

333 peaces ⋅ 1,00 €/peace = 333 €/kWh

In comparision one kWh out of solar energy that is currently payed with 0,57€ is indeed cheap.
So it makes sense to use accumulators and a good charger if you use equipment with high energy demands like digital cameras or remote controlled model vehicles.

Today there are size AA accumulators that have a capacity of more than 2500 mAh. With a durability of 1000 charge cycles that can be achieved with a good charger that means a accumulator can provide 2500 Ah during its live span.

The accumulator voltage is 1.2 V. That results in 3 kWh energy during live span. If the accumulator costs 5,00 € and the charger is 40,00€ then the costs per kWh are:

45 € / 3kWh = 15,00 €/kWh

If you use more than one accumulator the costs decrease even more:

for  4 accumulators: 60€ / 12kWh = 5,00€/kWh

Of course there are the costs for the electrical energy from the grid. For 0,20 € per kWh this are 2,40 €, in sum this is for 4 accumulators  7,40 €/kWh. The losses when charging and self discharge losses of the accumulators are neglected for this observations.