Battery problems in the first and second generation Honda Civic Hybrids have become a major concern for many Honda owners. The problem has been premature battery failure, which often is NOT covered under warranty. The affected vehicles are 2003 to 2005 Civic Hybrids (1st gen) and 2005 to 2011 Civic Hybrids (2nd gen).
The high voltage hybrid battery is part of the Integrated Motor Assist (IMA) system and is located behind the back seat. In the 1st gen Civics, the battery is a 144 volt nickel metal hydride (NiMH) battery. The 2nd gen Civic Hybrids have a more powerful 158.4 volt NiMH battery. The failure rate is reportedly higher in the 2nd gen Civics than in the older ones.
The average service life of the NiMH battery in the Honda Civic Hybrids is only about seven years, and in some cases much less. By comparison, the high voltage hybrid battery in the Toyota Prius has proved to be extremely durable and trouble-free.
The LA Times reports that over four percent of the hybrid batteries in California Civics have had to be replaced for various reasons, a figure which many officials says is too high to be acceptable.
Why the Batteries are Failing
The leading cause of premature failure with the Honda Civic hybrid batteries has been undercharging. Honda blames the problem on "frequent stop-and-go city driving with the A/C on, especially during warm weather. This type of driving can leave the hybrid battery in a low state of charge. Over time, this can cause battery deterioration and failure.
For maximum service life, the hybrid battery must be maintained at 50 to 60 percent of its full charge. This requires driving the car often enough to keep the battery charged up (at least once every month). If the car sits for more than a month (especially during hot weather), the battery may get so low that it never fully recovers and eventually fails.
Also, if a battery is allowed to fully discharge and is not recharged within 90 days, it may not accept a normal charge and fail prematurely.
Extreme heat can also damage the battery. If a car has been damaged and is repainted, curing the paint in a bake over that exceeds 150 degree F may damage the battery. Body repair shops are cautioned to not let the oven temperature get too high when working on a Honda Civic Hybrid.
Honda’s Fix for the Battery Failure Problem
Honda’s fix for extending battery life in the Honda Civic Hybrids is to reprogram the IMA control software. This requires taking your car to a Honda dealer for the update. There is no charge for the update.
The Honda TSB software update (09-058 and more recently 10-034) reprograms the IMA battery controller, the PGM-FI engine controller, and the CVT transmission controller. The update essentially "detunes" the IMA system so it uses assist less often to reduce the load and stress on the battery.
However, many Civic owners have complained that their cars do not feel the same after the update. They say their car does not accelerate as quickly and does not get the same fuel economy as before.
On the other hand, the update does reduce the risk of battery failure and may save you money by extending the life of the battery.
Here is a copy of Honda's Customer Notice letter, and details about the update:
Hybrid Battery Replacement Costs
If the battery in your Honda Civic Hybrid fails, it can be VERY expensive to replace if it is out of warranty. Honda dealers are reportedly charging $3000 to as much as $4000 to replace these batteries. The cost of the battery itself depends on which battery you buy.
A Honda refurbished hybrid battery costs around $2200 plus installation (figure about $200 for labor). The refurbished battery is a used battery that has been tested and individual cells replaced if found to be faulty. The refurbished battery comes with a one year warranty.
A new Honda battery (if available) is around $3000 and comes with a 3 year warranty.
Aftermarket refurbished batteries are also available from various suppliers (see below). Most of these batteries sell are currently selling for $1700 to $2200 depending on the source (plus shipping costs, installation and your old battery in exchange).
Should you consider replacing a bad battery with a used battery from a wrecked Civic Hybrid in a salvage yard? Although a used battery may cost less than a refurbished battery, it probably does not come with much (if any) warranty. Most salvage yards will guarantee the battery works or will replace it for up to 30 days if it fails to hold a charge, but beyond that you are on your own. Used hybrid batteries are risky because when the battery sits around in the junk yard for more than a couple of months in a discharged condition, some of the cells may never fully recover. The battery may work for awhile, but probably not for long term. The problem is that some NiMH cells discharge at a different rate than others. This upsets the internal charge balance of the battery and prevents the battery from recharging normally, which will eventually cause it to fail. However, installing a used battery may buy you enough time to sell or trade your car for something else before the battery fails again.
Honda Hybrid Battery Warranty
If the battery in your Honda Civic Hybrid fails while it is still under warranty, your Honda dealer will replace it at no cost. The standard warranty on the hybrid battery is 8 years or 80,000 miles, which ever comes first. The warranty date is based on the vehicle build date, not its sale date, which can be found on the build plate on the driver door pillar.
In California and other states that have adopted California’s SULEV emission rules (NY, VT, ME, MA, RI and CT, plus NJ, OR, WA, PA, NM and FL since 2010), any vehicle that is certified to SULEV emission standards gets a 10 year or 150,000 mile battery warranty. To qualify for the extended warranty, your Civic must have been sold and registered in one of these qualifying states, and must be certified to SULEV emission standards (which can be found on the emissions decal in the engine compartment). Your local Honda dealer should also be able to verify this information using your vehicle’s VIN code.
On Honda’s 3rd generation Civic Hybrid (2012 and up), a totally different type of battery is used (lithium ion) and the battery comes with a 15 year or 150,000 mile factory warranty.
Diagnosing Honda Hybrid Battery Problems
Your car’s self-diagnostic system will detect most problems that can occur in the hybrid battery or charging system. If a fault is detected, one or more fault codes will be set and the IMA warning light will be illuminated. To read the codes and diagnose the fault, a scan tool capable of reading Honda fault codes must be plugged into your car’s OBD II diagnostic connector (located under the dash near the steering column).
Though many aftermarket scan tools can read Honda codes, not all can read hybrid codes or access onboard self tests that may be necessary to pinpoint the problem. The best scan tool to use is a Honda scan tool such as the Vetronix Mastertech for 2003 models, or a Teradyne scan tool for 2004 and later models.
Honda Hybrid Battery Fault Codes
Any of the following codes usually means your Civic needs a new battery: POA7E, POA7F, P1435, P1446 or P1570.
Other battery related codes include P1447, P1449, POA9D, POA9E, POAC7, POACD, P1574, POA27 and POAE1. These codes indicate battery-related faults which may or may not require replacing the battery.
How to Recharge a Low Hybrid Battery
There is no high voltage battery charger that can be used to juice up a dead hybrid battery. So if your battery is fully discharged (no bars showing on the dash charge indicator), just start the engine and drive your car so the engine can recharge the battery.
For faster charging, you can remove the #15 fuse from the underhood fuse panel and run the engine at 3,000 RPM to fast charge the battery. When all of the status bars on the dash charge indicator are illuminated, the battery is fully charged.
A low or dead hybrid battery should not prevent your engine from starting because it also has a conventional 12-volt battery in the engine compartment, and a conventional starter motor to crank the engine. This system serves as a backup for the hybrid battery, and is also used during cold weather to start the engine.
How to Replace a Honda Civic Hybrid Battery
Caution: High Voltage hybrid batteries can be dangerous! A shock from a high voltage battery can be deadly.
Honda says to use the following procedure to disable the IMA system and isolate the high voltage battery:
Turn the ignition OFF and disconnect the negative ground cable from the conventional 12 volt battery in the engine compartment. This will disable the IMA controller and prevent it from routing high voltage into the IMA system. Then remove the back seat, remove the small switch cover on the battery pack, and turn the switch OFF (down). Wait at least five minutes for the system's high voltage capacitors to discharge before working on the battery or other IMA high voltage components.
If any work needs to be done on the hybrid battery junction board or control module, wear insulated gloves and use insulated tools.