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Newbie here, I’ve got a little problem that I’m hoping the group can provide input. Sorry for the long dissertation below.

Civic 2012, all factory equipment. The battery was replaced by a recall some years ago, not sure when.

About 12 weeks ago, we found the engine would turn over so slowly that car would not start. Sounds just like a low battery, but read on. Previous starts all seemed normal.

Charged battery for 2 hours. Removed the Positive and Negative cables, cleaned with wire brush, WD 40 and reinstalled. Seemed fine. We normally used car every day, but some days no use. No problem for a week or so. Then would re occur. This cycle happened maybe 4 times. Trend seemed to be when car was not used for 3 days or so.

Then 2 weeks ago drove 250+ km (about 150 miles). Next day, no start. Same issue, battery seemed to not have enough juice to turn engine fast enough for start. One or 2 short slow whirls, and now no engine rotation at all. Never any Battery or Alternator type lights on dash. No advisory lights at all, ever.

Charged battery a few hours. Put voltmeter on battery, 12.5 volts. As starter turns, analogue reading dropped to 10, engine starts immediately and meter now shows 13.5 volts. Then over next 60 seconds dropped to 12.5 volts. The vehicle has one of those sensors on the negative battery terminal that somehow detects battery condition, and allows lower voltage charge when the battery is good, it’s a fuel saving idea I think. So I thought these voltages were OK.

Mechanic said battery is probably the problem. It’s maybe 7 to 8 years old. New battery. Exactly the same problems. I charged the old battery 3 hours, then left it 5 days on my bench, then hooked it to my corolla and corolla started fine. So old battery probably was fine.

New battery put in Civic, car started just fine. Decided to put charger on for 2 hours, just to be sure.

2 days later start attempted, could not rotate fast enough to start. Same problem. Left car for 4 days, then put charger on for 2 hours.

Next day, same problem, just a short whirl noise as starter turned engine slowly, and no start. Drove my lady to her appointment in Corolla, then a half hour later, started no problem. Immediately turned off engine. Now I’m perplexed, but maybe battery is still very poor, and maybe just by luck engine started. So I decide to find out. I put headlights on for 5 minutes. Car started fine. Immediately shut down engine, and another 5 minutes of headlights on battery. Car still started fine again. WTF?

So I’m thinking definitely not Alternator problem.

My mechanic loosened then re tightened what few cables he could find underneath (a ground, I also asked him to reset any power to starter cable but I’m not sure he could reach that). He did an alternator check, it said 12.5 volts no load, and also 12.5 volts under load, and that means a bad ALTERNATOR.

Before I splurge on the alternator purchase, anyone have some thoughts?

Sorry for the ramblings…..

Dave

 
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use car-part.com and find a nearby scrapyard, locate a OEM alternator
aftermarket ones do not work well with Hondas, test with an used one first

I will be honest - my batteries don't last much longer than 2 years (sure, i don't drive my cars as much since COVID, but anything longer than 2 years is a given for batteries, especially with Cnada winters.

 
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So, you're thinking the alternator isn't charging while driving. The battery is then low when you park and therefore won't start the next day?

What about a battery drain happening overnight? It sounds like that could be the cause as well.

 
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Thanks for the speedy responses guys.

sdaidoji, our local scrap yard has a 2013 civic with one on it, outside in the elements, but it's "at least a year old, probably more". Do you think electrical parts do well when inactive for a long time?

Brotatoe, I was just thinking that. I disconnected the negative lead from the battery, put my analogue meter in line and read 250 + milli amps. The meter goes past full scale, so I'm sure its certainly 300 or more milli amps. Does that sound unreasonable? Doors close, hood open but no hood light. No theft protection devices. Keys in the house, not in the car. My 2002 corolla shows a 15 milli amp draw, way less.

Thoughts?

 
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pending price... have you checked the price for a new OEM alternator?

 
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That's a high load. I would expect the parasitic draw to be like 80 mA. The battery is probably around 80 Ah (amp hours is capacity) when new. With a 300 mA draw it would be completely dead in 11 days, compared to the Corolla's 200+ days with 15 mA draw. Below a 50% charge you may not have enough juice to start the engine. If the battery is old it will have even less capacity too.

I would suggest measure the parasitic draw, then start pulling one fuse at a time to find what's causing the large drain.

 
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Definitely some sort of draw

 
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I did find the draw. It was a fuse in the panel that is in the engine, number 29, marked "Back Up". When I pull it, draw drops down to 20 mAmps. thats's from 250 + MAmps to 20 milli amps. So I expect that my reverse lights to be the problem. Ok if so, I can get by without them

However, reverse lights work fine with the fuse out. But the Information Display, Or Multi Information Display, depending on where Honda refers to it in the owner's manual, is blank now. So...can't control the radio at all (can't seem to even turn it on now), nor see a bunch of warnings, nor see average fuel economy, nor see maintenance info. Plus, the key FOB will not work with this fuse out, the FOB will not unlock doors, trunk or sound horn alarm. The horn via the steering wheel switch does work fuse in or out

Any idea what "Back Up" means on the fuse label?

Should I keep on pulling other fuses, see if that causes an amperage drop too?

 
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Back up does not mean back up lights, I really don't understand why. Check out this extremely relevant thread:

https://www.civicforums.com/forums/3...itic-draw.html

 
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Very good thanks Brotato. Much infomation there, I will have to try many things. Dave

 
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Didn't mean go reply to that other thread, just thought it would give you some ideas. The next step would be find out everything that's on that fuse then go unplug one at a time until the draw drops. Unfortunately, I don't have a 9th gen Civic service manual and the 8th gen Civic manual isn't close enough to work.

 
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Well the draw is 1.2 amps. When I used my analogue meter, full scale was 250 ma so I could only quickly touch the terminals with the meter's leads. I had an used digital meter so tried that. 1.2 amps discharge

HOWEVER, after about 3 or 4 seconds of keeping the ammeter hooked up, that discharge dropped to zero (or maybe close to zero). So as some have already pointed out, that initial high draw may be only for a short time, and this was the case for my 2012 civic.

Just letting any interested readers know. Dave

 
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No more problems. It appears that perhaps there was a bad ground, or battery connection to the start system. That seems to be the only explanation that fits all the symptoms. My mechanic supposedly unhooked all he could get access too, and reconnected them, except for the connection right at the starter motor, apparently it was too inaccessible. No problems since after many starts. Dave

 
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Thank you for reporting back!