ChatGPT is not wrong... but in my personal experience, once you go below 40% it's all downhill from there. At least if you've done it 2-3 times. Batteries are n

ChatGPT is not wrong... but in my personal experience, once you go below 40% it's all downhill from there. At least if you've done it 2-3 times. Batteries are not always exactly the same, and temperature conditions vary as well. I've been nursing batteries for years, and this is just my anecdotal comments on that. One thing that we can all agree on though is that you must never ever use car batteries. Lead acid need to be the deep cycle kind.