Yeah i probaly will ill make a 2.1 update in the next week or so fixing and adding a few things aswell as a walkthrough but heres a quick guide for the batteries you can find them beside the towels in the garage, on the rotom Pc and around the back behind a bush box (Shrinking required to grab but can be seen when big)
as for the crystals you need 4 and all can be found in the dig spots sometimes when you dig you'll immediately pick them up if you are too close so sometimes you won't even see them, also one of the harder to find ones is in a bush pot outside one of the pool corners. I'll be adding in a counter for the crystals in the inventory screen when I make the next little update.
Hope this helps :)
Thanks for playing