Super capacitors / just large capacitors in general might eventually save the day here. The only issue is super capacitors can't generally bake in the heat all

Super capacitors / just large capacitors in general might eventually save the day here. The only issue is super capacitors can't generally bake in the heat all day and still work for 3-5 years like lead acid batteries can. Supercaps is how "fast" charging in most smartphones works as well since they can soak current faster than the battery itself and also mitigate cycling batteries too hard.