On the topic of batteries, I thought I would comment just because I tried a Lithium Ion battery this year. My experience so far has been exceptional, so I am quite excited about it, and I really was skeptical going into it.
I picked up an Anti-Gravity brand battery. They make one in a case that is direct replacement size for the GT-R (no need for custom brackets or hardware), which is already smaller than a Z battery to begin with. It was a 18.4 lb reduction from the standard GT-R battery, I imagine 20# maybe more reduction for the Z. I will definitely be getting another for the Z. It has crossed my mind to perhaps make a little batch of hold-downs to put this GT-R size version into the Z. I would love the extra space in the battery compartment personally.
The car cranks as hard if not harder. The battery has an internal kill switch that allegedly detects when the battery is getting low, if there is some sort of drain, and shuts itself off leaving enough juice to crank the car a few times. There is a button on top of the battery to reset that kill switch, and there are also some key fobs that do it remotely included with the battery. I can only assume this feature works correctly, as due to the phone app, I cant see how I would ever find myself in a situation to need it.
Which brings me to this device, which is not technically part of the battery, but part of the package I installed and I love this thing:
https://antigravitybatteries.com/pro...acker-lithium/
Its a bluetooth transmitter for your battery. Add the free app to your phone. Any time you are within range of the car/battery, it syncs data and sends any appropriate notifications to your phone. So the app gives you a battery percent gauge just like your phone has for its own battery, and you can also set alert points of when to send a notification to your phone about battery percentages... Example, send an alert to the phone when battery gets down to 40% or etc. Then you know you better get out there and put on the trickle charger.
So having this tracker, and assuming the car is parked inside the home garage within bluetooth range of your phone, I really dont see how you could ever have a surprise dead battery.
PS this battery tracker device from Anti-Gravity is cheap, like under $40, and they also offer it for lead/acid batteries (different part number). I have been meaning to go and order a couple more for the truck and harley. I dont personally know enough about batteries to know if something like this can be as precise/accurate on a lead acid battery or not? But I am going to try it.
Sorry for the long sales pitch post, I just really dig this new battery situation I have going on and think everyone else would be happy with it. Now it just has to keep working a few years and not burn my house down.