Which rechargeable battery type for infrequent and low dosage charging
I know no Battery technology which likes cold. Maybe you need to protect / heat the battery

my first thought is some lead based battery (I knew they are used for emergency power in industrial scale). They keep charge for a longer time.

the short charge bursts might be a problem. One Solution might be collecting enough energy in supercaps and then transfer that into the &quot;long term storage&quot;

3V3 or 5V... No. High voltage is your friend. At least for the battery. You will need a converter.


Appart from that, it sounds complex and special. Its hard to deliver a 100% solution for that