New owner of a Gen 1

Wanted to take a moment and say HI! I just bought my first Gen 1 Insight last weekend, and I am really excited. This one has a few issues that I am working out but hoping to have it on the road by next Monday.

Not a bad little car so far come with a extra IMA battery and a grid charger installed and a MT trans. It has about 160k miles. Not in to bad of shape for a car that has sat for the last 3 years.

So for the issues I am working through is one, I know the 12v battery is died and not holding a charge. That will be replaced with a U1 everstart battery from Walmart. Cheaper and less weight. Also going to throw a small solar panel to trickle charge it. Next issue I think the IMA in the car now is bad, The IMA light is on and after letting it grid charge for a little while and turn off the grid charger I can watch the volts drop on the IMA. Also if the jumper cables are hooked up to the 12v it will stay running but when you unhook them the car dies out. So the IMA is not charging the 12v. From what I read that sounds like a died IMA. Another little annoying issue is the AC does not work. Hoping a recharge might fix that and the side skirts are not there for the rear. Plus it needs a really good deep cleaning.

Couple questions. Can I remove the grid charge and charge the spare IMA battery outside the car to see if that is any good before I get a hold of Bumble Bee battery's? Any other advice for a new owner on owning these little gems, maybe some upgrades?

Thanks in advance!