- So if I had a 60 volt battery. I couldn't just dump that energy straight to the battery multiple times until I achieve the Vmax of the battery. Is it necessary to use the boost type switching when you are continually adding that to the battery until its filled. And when you do transfer the energy, I presume the capacitor will be emptied unless of course the battery is full. Is any of this correct so you wouldn't lose current?
Well. You would still need a boost converter and here's why:
The voltage of the battery and capacitor are both 0.
The voltage of the capacitor goes up to 30V.
The capacitor and battery are connected together and a few amps begin to flow into the battery gradually raising the voltage.
The capacitor at this point is currently loosing voltage, for sake of argument, the battery and capacitor are now both at 15V.
The capacitor is no longer charging the battery, because the voltage in the capacitor is no longer higher... (like water flowing down-hill)
You disconnect the capacitor and repeat the process. Although this time the battery goes up to 21V.
You disconnect the capacitor and repeat the process. Although this time the battery goes up to 25V.
You disconnect the capacitor and repeat the process. Although this time the battery goes up to 27V.
You disconnect the capacitor and repeat the process. Although this time the battery goes up to 29V.
You disconnect the capacitor and repeat the process. Although this time the battery goes up to 30V.
You disconnect the capacitor and repeat the process. Although this time the battery stays at 30V.
So, if you repeat the process multiple times, you 'may' eventually get the battery to be charged to what the capacitor is, but never more.
Using a boost converter will raise the voltage higher, which will ensure that the current flows into the battery.
Additionally, when the voltage is very different like at the beginning, you risk damage to the battery, as the current flow can be quite high.