Not even sure if this is a problem or not because I recall reading about it before, but the past few days it has been extremely hot outside. Mid 90s-100. Abnormal for Ohio weather. My car hasn't had a hard time starting itself, but the battery seems to be struggling to turn the car over. I've never had this problem before and I find it coincidental that this is the first time I've experienced it and that we've had this very extreme heat lately. I put a 12V 10amp charger on my batter for 2.5 hours last night and came out this morning and same issue. However, if I leave the charger on the battery in "crank mode", no issues - turns the engine over just fine.

I had a local towing company extensively test the battery/electrical system and everything seems to be fine - battery reads 12.7V, no abnormal resting system drain, alternator is charging battery just fine, etc.

My only thought is that the battery might be going bad, but I don't want to replace the battery if it's the extreme heat that is causing it. I do have a system that is pulling 600w RMS that I listen to frequently and come to think of it when I was installing my suspension I was listening to some tunes and ran the battery out a couple times to where I had to use a jump starter. This was also in the extreme heat.

If it helps, the battery is from 2011 and is a maintenance free battery.

Thanks for reading.

PS - only closely relevant thread that I could find: https://acurazine.com/forums/3g-tl-2004-2008-93/those-lack-power-surging-hot-weather-859713/

 

I think this is where your problem is. I'm not an expert, but this is the most logical explanation. Normally running it flat once or twice might not hurt the battery, but in extreme heat like that, anything's possible. Get a new battery, and if it fails then use the warranty that comes with it to get it replaced. The heat won't stay around forever.

 

^This

 

^This

 

needs new battery and dont deep cycle the new one.

 

Unless the charger is self-limiting in output, it is very easy to overcharge and damage the battery, esp. in high heat conditions. But the fact that the vehicle starts easily when the charger is in "crank mode" and supplementing the voltage to the starter, indicates a bad (weak) battery.

Battery voltage can only be properly checked when the battery is in "resting" mode, that is, after it has sat for 12 hours without any load, other than the normal parasitic drain. Even a weak battery will read appropriate voltage, just after the car has been driven, or the battery charged. The surface charge must be removed, for a valid voltage reading.

See this link for more

https://acurazine.com/forums/showthread.php?t=890429

or this one

https://acurazine.com/forums/showthread.php?t=775689

A good battery should have no trouble starting the vehicle, even in high heat. Cold (below zero) will cause problems but not heat.

However, high climate heat will shorten the life of a battery more than will cold climates. And of course, if the vehicle only has trouble starting after it has been driven, and left sitting in the heat, then suspect the starter, not the battery. The starter solenoid can heat soak, and cause starting problems, although this is often more of a problem when the exhaust system is routed directly by the starter/ solenoid.
---eof

 

^^ Best explanation yet.

 

Even in the winter, the battery can be at rather high temps, when starting the engine, if the car has been driven to normal operating temps, and then parked for 1/2 hour - because the engine heats it. That is why there is usually no problem with starting, even when the summer temps are *high*.

After driving the vehicle, the engine (and battery) is always *high*, winter or summer - the difference is just not that great. But 150 (or more) at the battery, inside the engine bay after driving, is not unusual. Remember that the engine is running at 200 or so.

So mid 90s - 100 degrees ambient is not what I would consider high heat.

And just to be clear what I consider high temps - last week it was 107 (in the shade) at 5pm, and after sitting for 1 hour in the sun, my 15 year old Chevy 4x4 with 4.3 V6 started instantly with a Bosch (PepBoys) battery - and it was 126 degrees on the drivers seat (in the shade of the vehicle roof) - I had accidentally left my very accurate thermometer inside, which I was using to test the A/C earlier.

And my RDX similarly started all week when the temps were 102-105 degrees in my garage. And has started just fine in August in Las Vegas - I shudder to think what the temp actually was, but it definitely was way more than 110.

When the temps are like this, I once had the GM body shop measure (with an infrared thermometer) the temp at 150 degrees on the roof of my all black Camaro. Of course, that was in the sun - so sun or shade makes a big difference.

I believe that Consumer Reports tests battery charging and life, at 165 degrees.

Finally, I will note that the battery box in my RDX is excellent, and keeps the battery temp way below the temps in other parts of the engine bay. That is also partly due to the air-flow management of the battery box and surrounding ducting. I do not know what kind of temp protection is provided for a TL battery.