I have a 1991 Acura Legend. In colder weather ( once it gets to near freezing) my car won’t start due to the battery being low on charge. Once I jump it it starts right up but over night or sooner it loses its charge. I have replaced the battery at least 3 times in the last year. AAA has run a set of tests on the alternator and other electircal components and finds no problems. Do you have an idea, what the problem may be?
Do a quick lightbulb audit. If you have a light that is stuck on but not visible it could be killing the battery. e.g. glovebox, under the hood, trunk. Most of these turn on and off by a switch that is tripped by opening said glovebox, hood, trunk. If the switch or sensor is bad/stuck, the bulb could be staying on after you close it.
I can do that but also note it only starts doing it once it get about 30 degrees out during the night. During the summer and other warmer weather it never does it.