Twice in the past two days (yesterday and today) I’ve needed a jump for my 2019 Nissan Sentra. I’m thinking that my headlights are switching on more easily than they should, by me bumping the turn signal. Both of these happened in public areas, after I was at those locations for 2 hours or less (specifically, the library where I volunteer yesterday, and the antique mall where I have a booth today).
This afternoon, I stopped at O’Reilly’s on the way home when I saw they do free battery testing, and a very nice young lady came out with a machine and tested my battery, starter, and alternator, and they all looked OK but she did say there was a little “crud” on the battery anodes. While I was at O’Reilly’s, I bought a can of battery cleaner, which has a pH indicator that turns pink if the battery is leaky, and I used it when I got home and it did not turn pink.
FWIW, I put some tape on the turn signal so it won’t bump the lights into the “ON” position unless I put it there.
Disconnect each battery connector, and clean everything thoroughly with a brass bristle brush. Reinstall each. Connections should be clean and tight. See if that fixes your problem.
I have heard of folks having a faulty relay that controls the AC clutch. It stays stuck on when the AC and the vehicle are off. But it should still not drain too fast.
I actually drove for about 15 minutes, which was how long it took me to get home, after each jump. I later had to take something out to my car, and started it up just fine.
Here’s what happened to me once upon a time:
It was an old pickup truck. When you opened the hood, a little light bulb came on. Unbeknownst to me, the light bulb stayed on when you slammed the hood shut. Took forever (and many jump starts) to figure this out. Fixed the problem by removing the bulb. Didn’t investigate any further. YMMV.
When this happens. Does the engine turn over at all? Is it cranking very slowly? Or not at all. Just a click sound when you try to start it. If you are familiar with operating a multimeter you can disconnect one battery lead and insert the meter set to current reading. Should be just a few miliamps or zero. Unless you also have under hood lighting. Then it will be more.
I had an old Nissan (1980 or so) acting up. It was erratic, then the accelearator pedal sparked!
Turns out the other end of the ground connection wire was bad, there was one small wire connected to something (the engine? hence the spark) and so not a good enough ground.
Batteries can read 12+ volts and still be unfunctional as one or more of the cells is not functioning. My Scion died friday, recharged it slowly saturday, then dead again today, so new battery this afternoon.
This same thing happened to me when a sensor for the backup lights went bad, so they never turned off. It took a while to figure out until I went to the back of the car. My brother had a similar problem when the dome light stayed on.
I suppose a switch issue is possible, but I personally would suspect a stuck relay or something else drawing power when it shouldn’t over a simple switch.
I used to have an old Cadillac with a sticky fan relay. The first time it stuck it drained the battery. I noticed that the radiator fan was still running quite some time later, so I opened the hood and smacked the relay box. The fan shut off. I started paying attention to whether or not the radiator fan shut off or not when I stopped the car. On one other occasion the relay stuck, and again, smacking the relay box made it stop. I was going to replace the relay if it kept sticking, but apparently my smacking it twice managed to fix it. It never stuck again. Hooray for percussive maintenance!
The fan relay is fairly noticeable since you’ll hear the fan running if you listen for it. If it’s a different relay like the AC clutch relay suggested upthread then the symptoms might not be so obvious.
They tend to undersize batteries a bit these days, mostly to save weight. I always put the largest battery (in terms of cranking amps) that will fit into my vehicles, and the batteries typically last longer than 7 years.
Auto start batteries don’t take deep discharge well, and while a jump start will get things going again it presents a heavy load on the electrical system. A battery charger is your friend here. One thing, I’d think a 2019 model would have circuitry to prevent lights from being left on.
Conductance testers are useful, they convert the DC battery voltage to a high frequency AC signal and feed it back through the plates or somesuch, and determine battery health that way, potential CCA. They do a good job of spotting defective batteries. I notice in the advertisement though they call it a load tester. I’m a little skeptical of that, simply looking at it, I mean maybe, but ordinarily a genuine load tester is a bulky affair and uses carbon piles. They produce lots of heat, it is basically a controlled short circuit.
I’m not sure how it works, TBH. Am guessing it briefly connects two or three different loads to the battery, one at a time, and then calculates internal resistance and CCA. And am further guessing “brief” is a few tens of milliseconds, given the size and weight of the unit.
Right, i own a conductance tester, they are excellent for weeding out a bad battery. By that I mean if they indicate a defective battery, then it is almost certainly a defective battery. But the reverse is not necessarily true. A true load test is the gold standard for battery testing. I am doubtful a device like that shown is placing any meaningful load on a battery. But it is easy to see why the conductance testers have found favor.
For all that a simple voltmeter can be used to replicate load testing, sort of, by measuring battery voltage sag during engine crank while engine start is disabled. But as someone noted above after several years most car batteries are on the way out. Leaving aside things like loose or corroded terminals or lights or accessories left on inadvertently, the mere fact a jump start has been necessary twice now means that particular battery is pretty much done moving electrons around.
What do you and Crafter Man think of the desulfinator/chargers? I have oversight of 10 or so household and work vehicles, and it seems we sure spend a lot of time fooling around with batteries and chargers etc.
4 of the vehicles are on trickle chargers, as they are not driven regularly, and discharge themselves unless they are on chargers. (cranky english collectables)
I purchased a couple of the Noco desulfinator/chargers, Im not quite sure yet if they do as advertised, but at least they can charge. Thanx. also for discussion of Conductive tester and link. I should probably buy, I use a multimeter now.
There is sometimes an issue with the brake switch. The car will not start because the brake switch is not operating. Does not detect you are indeed pressing the brake pedal. It is located above the brake pedal and can be removed by turning counter clockwise. There may also be a cruise control switch there as well. Spraying some electronics cleaner into the switch may help. Make sure the cleaner is safe for plastics.