2008 Honda Civic intermittent starting issues - electrical problem

Hello all,

A brief history, as it may be relevant:
-I’ve got a 120k mile car with a 50k mile engine thanks to a recall.
-I got side-swiped at about 10mph, and since then I notice water droplets in my turn-signal
-My plastic (nylon?) undercarriage protector parts that go under the front grill, and driver-side wheel well were ripped off, and then slowly replaced (because dealership backorder) so, again, water may have been where it was not welcome.

The issue: A couple months ago I noticed that the starter was occasionally struggling to crank when I started it. This is in temperate weather, nothing extreme. The first couple times, it struggled, but eventually started. So I took it to dealership and asked them to check battery/alternator. They said that if it were an alternator the light would come on with a code, which it did not. So they said to go to their ‘quick service site’ which does oil changes and easy stuff and have them check the battery. I did so. They said battery wasn’t young, but seemed ok. I left with no work done.

Next time it happened at a gas station only it didn’t start at all. Seemed like battery nearly dead. Barely cranked on 1st try. Even less so on second try. I didn’t try a third time, I called AAA. They sent a guy, he tested my battery (maybe 3 weeks after previous test) and showed me the readout on his tester which put it a bit into yellow ‘replace soon’ category. I figured I’d just do it now. He put in a new battery and, of course, it started just fine. It was hot that day, and I’d just driven 45 mins with AC on before it failed to start.

So now I have a brand new battery. And it happened a couple more times. Started, but seems just barely able to do so. I bought one of those lithium jump starter battery packs, and that seems to have magically solved the problem for a week or so now, but I fear it will come back again.

Any ideas?

I am wondering if my AC could be drawing way more power than it should be, or perhaps it is preventing the battery from properly charging while running. I am also wondering if water is in something that doesn’t like water and it’s causing a drain.

It appears they dismissed the alternator as a cause and no one has ever gone back to check it. This is where I would start. A simple check to see if it is functioning correctly. It could be marginal but not set off a diagnostic light. Why they wouldn’t do a 2 minute test to rule it out is beyond me…