I have a 4th gen Prelude with 138k miles.
There were no electrical drains. I didn't even leave my alarm on. Today I get in my car and there's barely enough juice to start it. Is that enough to diagnose anything?
TIA,
-Dan

 

sometimes you can bring your battery to a shop and they can run it on a tester (we have one where i work) and they can tell you if you need a new battery. try that first... how old is your battery maybe it still has a warranty.

 

could just be a bad battery.

 

alternator didn't do its job the day before?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by STARRMAN85 &raquo;</TD></TR><TR><TD CLASS="quote">alternator didn't do its job the day before?</TD></TR></TABLE>
Well, I started it a few times that day, and each time it seemed like the battery had gained charge proportional to the amount of time I'd been running it. So I think the alternator's fine.

 

One popular way for a battery to go bad, is to have an internal short. So it discharges itself overnight even if you didn't leave your lights on. That sounds exactly like what's happening, It's happened to me before. One day soon it's gonna go dead much faster, like within hours...

Keep an eye on the electrolyte level in the battery, keep it filled with distilled water. But that's more for the new battery you're gonna buy. It might be too late for this one.

 

to rule out the alternator, start the car and test the voltage at the terminals of the battery. should be around 14 when charging.

 

I would check the alternator. Because it couldnt of been working and the car was running off the battery. They will run for a while with a bad alternator. (depends on condition of batter and what you have turned on in the car) That would be my choice

 

Well, now the story has changed. I took it to a mechanic I trust, and had him do an electrical system diagnostic (check for drains, etc). Turned out I needed a new battery. So I buy this battery and install it. When I turn the key to ON, everything powers up. But when I try to start it, the whole system shuts down! Dome light turns off and everything. WTF?
So I disconnect a battery cable for a second, reconnect it, and try again. ON, everything powers up. Try to start, and it sounds like some circuit breaker kicks in. I don't think he sold me the wrong battery. WTF? Now I'm really confused!

 

the battery you bought might need charging...

 

check for blown fuses

 

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I find that unlikely. It makes a pretty powerful pop when I try to start it. Also, with an almost dead battery, the interior lights are pretty weak.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TeStUdO &raquo;</TD></TR><TR><TD CLASS="quote">check for blown fuses</TD></TR></TABLE>

In the morning, when it's light out, I will.

 

i myself just had to buy a new battery yesterday for my 92 accord. brought it to autozone after i got it jumpstarte, cuz they can test my battery and alternator, and my alternator was showing like 14 volts while car was on, then turned it off, battery was only showing like 5 volts.