It may be time to look at the nuclear battery option. Of course you will need to rebrand it's name. Nuclear scares the bejesus out of the moonbats.
Why? They have very low energy densities for their price. (But roughly comparable to the best batteries in terms of weight.)The fact that the energy levels are maintained for very long periods is their only advantage. The only terrestrial use was Soviet facilities in the Arctic.
They are useful for deep space probes beyond the range of solar cells.
And having lumps of radioactive materials all over the place should concern any sensible person. BTW is Moonbat your word of the week?