aggieEVO

iTrader: (11)

Hey All,

About a week ago I got to my car after work and found the battery dead. Got a jump start, made the 20 minute drive home with no issues. It was a mini battery. Not an Odyssey. Not automotive grade. Just a VRLA with automotive posts. I assumed it couldn't take the heat, as it's just started to get close to the 100s during the day. I charged my full sized and kept it in the trunk for a week with my jumper cables and ordered a PC680. Only had to use the cables twice over the past week.

I installed the PC680 on Thursday morning and she fired right up. No issues Thursday after work or Friday at all. Yesterday around noon I went to get something out of the back seat and my keyless wouldn't pop the doors. Voltage was super low and the car wouldn't crank.

Grabbed my test light this morning and found that under the hood, fuses 16-21 (all related to the headlights) are pulling some voltage. Is this normal?

Anything I should look for quickly? I haven't made any recent changes to the car.

Brady

Tekniq

iTrader: (11)

I am in no way a electrical expert. But im going to out on a limb and say, that might be normal only because I know the headlights work car off no key in the ignition.

https://www.evolutionm.net/forums/ev...s-how-fix.html

aggieEVO

iTrader: (11)

It had been a while since I've had to check for draw on a car. Did this on a Prelude I flipped many years ago. Proper thing to do is pull the negative cable and measure for amp draw between the cable and post with door closed and key out. I'm showing. .18.

TheBoz

iTrader: (9)

Did you check your alternator? You should see 14.3+ volts while running.

There is a spec in the manual, and as it gets warmer or colder cannot remember but it should always be over 13.5v

aggieEVO

iTrader: (11)

Voltage at the battery with the car running was 14.3. I replaced the alternator last year.

Biggiesacks

the headlights are not open circuit when the car is off so seeing voltage across those fuses is normal. The real question is how much total current is the vehicle drawing off the battery. As mentioned above the best way to test that is putting your mutlimeter in current mode and putting it in series with the negative battery cable and the terminal on the battery with the car off, doors closed etc. I would say anything above half an amp draw is concerning.

edsct9a

iTrader: (5)

What extra electrical items do you have? I've been running the small batteries for years and every now and then it would be to low to start. I got fed up with it couple months ago and finally hooked up a meter to it and my amp draw was around .20-.30. This didn't seem much to me but I started to pull fuses out one by one until I found the fuse that powers the radio and other interior stuff to be causing the draw. Pulling this fuse out dropped the amp draw to .16. I disconnected my radio and gauges and no luck. I finally unhooked the turbo timer and that was causing the slight draw with the car off. It was such a small draw that I didn't think it was the problem but it has started right up since then.

aggieEVO

iTrader: (11)

No real extras. I've been running this setup since late last summer. Just running an Alpine head unit, boost and AFR gauge. I also keep my laptop plugged into a converter, but that doesn't run when the car is off. I believe I even had it unplugged while troubleshooting this.

I hooked up my test light and have pulled every fuse. Still a draw somewhere. None of the fuses caused the light to go off. Under the hood and under the dash. Do we have a 3rd on the side of the dash? I forget...

Biggiesacks

a test light is not a particularly useful tool for this kind of troubleshooting. If you don't have one, this would be a great time to pick up a multimeter.

aggieEVO

iTrader: (11)

I do have a multimeter. Measuring from cable to terminal showed .18 amp. I should switch it to mA and see what I get. I'm currently checking my battery voltage every hour to see if it's draining.

On a side note, occasionally my boost gauge will stay on after I turn off the car... I just noticed this on Thursday night. I ran into the grocery store and came back out and could see it illuminated while walking up to it. I turned the car on and off, and the gauge was normal.

It's an old gauge and was in the car when I bought it (Prosport peak/hold). I've been meaning to replace it with an AEM to match my AFR gauge. Maybe I should consider it.

Biggiesacks

yah somehow i missed that you had done that test. .18 is pretty low, sounds about right for the ecu/radio/dash clock/airbag ecu memory. That kind of a draw should not be wiping out your battery unless the battery itself is going bad. Also dirty battery terminals can cause some headaches as well.

aggieEVO

iTrader: (11)

Brand new PC680 with brand new automotive terminals.

Battery has been sitting at 12.4 for the past 5 hours. Interested to check it late tonight.

TheBoz

iTrader: (9)

Pull the mfi relay. I have an issue on my car where the relays latch open or closed do t remember the correct term.

aggieEVO

iTrader: (11)

So, it seems like whatever drain I have stops pulling when I pull the battery. If I run the car for a decent amount of time... like my commute... then leave the battery connected, it'll drain fairly consistently during the day.

If I try to troubleshoot the issue and pull the battery cable, whatever is draining seems to stop. I'll hook the cable back up and the battery won't drain again until after I run the car again. I can let it sit for a couple days and it stays charged.

How can I test for the drain while leaving the battery connected?

Biggiesacks

The p680 only has a 16amp hour capacity. That's why it's dying so fast. The typical lead acid for our cars are like 75-90 amp hour ( a decent one anyway). Mini batteries are known for not lasting very long and you should probably get a float charger if you wanna keep it and have the car sitting for a few days