2005 Civic Hybrid in 'great condition' can't keep 12V charged.
 

I have a 2005 Honda Civic Hybrid that keeps dying. I've had to get it jumpstarted about 8-10 times in the past two weeks. What's even frustrating is that no-one can find anything wrong with the car. I recently made a 1900mi move and got the car checked out before. The mechanic did some stuff (replaced some fluids and brake pads) but said my car was in good shape. I thought he did a good job, but I don't think think he's too familiar with hybrids.

Issues on Trip:
-Car seemed a little weak sometimes.
-IMA battery meter was usually low, one or two bars.
- Occasionally IMA battery meter would shoot up to full charge, or rapidly decrease.
I've heard this might mean a marginal hybrid battery?

Issues after move:
-12V battery keeps dying, I have probably had it jumped a dozen times or so. The last time AutoZone tested my battery I had to take it out for them to charge it before they would test it. I drove it back home (actually ended up getting lost, so it was a long drive) and car was completely dead by the morning. I've had AutoZone test my battery twice, taken it to one independent shop (was told my car was fine), and taken it into the dealer (also couldn't find any issues).
-Lights also come on right after I jump it (red engine light?, IMA light, and ABS light) but I can always clear those by turning the car on and off. The dealer did not find any codes.

How can I diagnose and fix these issues? I've seen battery testers advertised but I've also read that the charger for the 12V is kind of weird, making a lot of common testers useless. I'm considering just disconnecting the negative wire every night so that I could see if it's getting charged. I'm also suspicious that the charger/IMA might be marginal and making 10-15m one-way trips isn't doing enough to charge it. I think a dead 12V should wipe out most codes. But the counterpoint to that is that I don't have codes or lights during normal use.

Re: 2005 Civic Hybrid in 'great condition' can't keep 12V charged.
 

The IMA gauge behaviors you describe are recalibrations due to imbalance and/or impending failure.

If your 12V battery has been run flat as many times as you have indicated, it doesn't matter what anyone says. The battery is damaged and should be replaced.

Replace your 12V
Replace your (-) battery cable.
Replace your ground straps.

https://cimg1.ibsrv.net/gimg/www.gre...92a84dfab2.jpg

Once you have confirmed your 12V battery is healthy and you have good ground connections, you can do meaningful diagnosis.

Re: 2005 Civic Hybrid in 'great condition' can't keep 12V charged.
 

Ok, thanks. I'll do that. Are non-OEM cables ok, and is this something I could do with minimal tools? Also a coworker suggested I unscrew the negative battery cable overnight so it wouldn't die. I did that and was still able to turn interior lights on. And it was dead in the morning. Is this because it's a hybrid?

Re: 2005 Civic Hybrid in 'great condition' can't keep 12V charged.
 

Non-OEM cables are fine provided they are the same gauge and flexibility. Minimal tools are required.

"Unscrew the negative battery cable" is incomplete. Loosen cable at (-) terminal and REMOVE cable from battery terminal is more complete.

If one of the cables is disconnected from the battery, there should be no power to the car. If you have something added (alarm system, etc.) that is directly wired to the battery, it should be removed.

Re: 2005 Civic Hybrid in 'great condition' can't keep 12V charged.
 

Verify that when you turn the car on the IMA and CEL lights briefly appear. If the bulbs are out the car might be in a state of IMA failure and you would not know it.

If you have a voltmeter check the voltage on the battery when the car is running. ( If you don't have a voltmeter pick one up - they are just a few bucks these days, for instance at Harbor Freight.) On most cars it should be around 14 volts, maybe as much as 15.. There might be something off in yours, so that the voltage is too low or too high, either of which will mess up the 12V battery. When fully charged and the car is not running it should be around 12.6v.

I agree that you need to replace the existing 12V battery, but you also need to know if it isn't charging right, otherwise the next one won't last long either. When I was a kid my mother had a car where the alternator was putting out much too high a voltage. Initial symptom - dead battery. The "mechanic" changed the battery twice before finally checking the voltage. Much cheaper to check the voltage first!

Re: 2005 Civic Hybrid in 'great condition' can't keep 12V charged.
 

The lights do come on after I jump them, so those are working.

Is the voltage test actually accurate for my vehicle? I thought that it didn't test much for my car. I think the car normally stops and starts charging the 12V when driving, so I'd expect to get some unusual readings.

Re: 2005 Civic Hybrid in 'great condition' can't keep 12V charged.
 

Again, you've flattened your battery so many times, it's dead. Period. Even with a good charging system, your battery could be dead overnight. Even if it's not dead, it's so damaged, it will screw you at the first opportunity.

Replace your 12V
Replace your (-) battery cable.
Replace your ground straps.

Once the above is complete, then meaningful testing can begin. The first step is to hold rpm at 2000 and check battery voltage. You can also easy-mode it with a voltmeter in the cigarette lighter:

Re: 2005 Civic Hybrid in 'great condition' can't keep 12V charged.
 

Unfortunately the 12V is not an issue right now, I got into an accident and my car is not driveable

I hadn't figured out the exact issue with the car, I'm in the middle of moving and I wasn't entirely comfortable swapping out wiring. So I looked around for a shop that would do that and didn't really have much luck, most places weren't interested in swapping wiring without actually diagnosing it. But swapping wiring seemed easier than I was expecting after I looked into it some more. So I was planning on doing it myself before the accident. Interestingly enough I did manage to get some codes off by taking it into an autoparts store, one of which was P1601, an IMA related code that didn't trigger the light. I'm not really happy with being charged by the dealer to check the hybrid battery and being told nothing was charged after that. I'm curious about what the issue was, I still suspect it's an issue with the hybrid battery pack.

But right now I'm looking for a new car, I'm looking for a used non-hybrid Toyota or Lexus. I'm not happy with the issues I've had over the past few months. Thanks for the advice earlier though.

Re: 2005 Civic Hybrid in 'great condition' can't keep 12V charged.
 

Hope nobody was injured! Corollas are good cars with high MPG. Mazda 3's are more fun to drive but Mazda drivers complain about them rusting quickly in areas that salt the roads. (Anecdotal evidence from a lot of owner griping, for all I know Mazdas may not rust any faster than other econo boxes.) If you live in a salt free area give the 3's a look.

Re: 2005 Civic Hybrid in 'great condition' can't keep 12V charged.
 

Fortunately no-one was injured. I'm in California right now, so I'm not worried about salted roads. I've checked out the car, and I actually really like the look. And I think I'd like a hatchback. Are Mazda's reliable? Looking at TrueDelta and dashboard-lights it seems like Mazdas are more problematic than other cars. It also seems a little more pricey than I want. Because I just got in an accident I'm more interested in safety features, particularly collision detection. It looks like the features I want are limited to the Grand Touring trim.