Hello everyone,

I'm new to this forum and is my first hybrid. Recently purchased a new 2013 Honda Civic Hybrid with 150 miles on the odometer fresh from Honda Dealership in Florida. My Civic was parked at the dealership for over 15 months and only 150 miles was driven from test drives. I've noticed the IMA battery will drained down to 20 to 30% in city traffic and the Autostop function was disable from time to time as well. On the highway doing average of 75 mph I can only manage around 37.7 MPG, while IMA battery (at about 40% show on the screen) never really assisted the motor and needed to be charge randomly. So my question is could my IMA battery gone bad already from sitting at the Honda dealership without being driven? So far I put on 500 miles since the purchased and can only manage 36.5 MPG mixing city and highway. And NO I wasn't driving like an dumb ***, since it has less than 1000 miles on the new motor I've never gone pass 3500 rpm yet.

 

Try a new 12v battery first. The OEM (151R class) size is more expensive (but lighter ) than a 51R class, but an 51R class fits just fine.

R means reversed posts. Non reversed works too, but it not as nice when installed. Wires are stressed.

Try it first, then start worrying about the "IMA battery".

Not endorsing, but Costco sells a good battery (same manufacture as BMW batteries) and they have an amazing return policy. If you find it's not the problem, returning is simple.

 

I had a similar problem, but the Costco in my area doesnt sell 151R or 51R batteries. Autozone, Advance Auto Parts, and Napa were the three stores in my area that did. I ended up buying the one from Autozone because it had more Cold Cranking Amps (They were all around the same price). It didnt make a difference for me, but I have heard that changing the 12v battery has worked for others.

EDIT: I just got back from the dealership(I'm getting my IMA battery replaced under warranty on Wednesday) and they said having a car sit (and not be used) for long periods of time is the #1 killer of hybrid batteries. Not sure how true that is from the anecdotal evidence I've scrounged up on the internet, but it's worth mentioning.

 

Look under your hood (well at least on my Honda 2014 Civic Hybrid sticker) and it states "If this vehicle is unused for over a month, the service life of the 144V Lithium-ion battery will be reduced and the battery may be permanently damaged. Drive the vehicle for at least 30 minutes a month to charge the 144V battery. " So yea I think being stuck for 15 months would definitely do a number on the IMA battery. As far as driving on the freeway doing 75mph you're only gonna get 35-38 mph. Drive 65 mph or 60 mph and you'd get better gas mileage. At 60 mph I can get 53-56 mpg on mine but drives everyone behind me crazy lol so I stay on the slow lane. At 75 mph you're using mostly gas so the IMA rarely kicks in unless you go uphill then it'll pitch in with the assist. Your IMA on screen isn't always gonna be 100% charged when you're actively punching it but every time you slow down or go downhill without hitting the gas you'll see the IMA charging and if it's a big downhill you can charge it 100% but gets depleted once you level off and start accelerating again. At least that's how I noticed my Civic performs. Hope this helps.

 

OP,

You're not going to get great mileage at 75mph. It has nothing to do with whether the IMA assists or not. It has everything to do with the amount of energy required to overcome the drag associated with the airflow (mostly, rolling and mechanical resistance are relatively constant and ignored for this exercise). Drag increases by the square of velocity, so 75mph takes (75^2-65^2)/65^2 = 33% more drag than 65mph. Internal combustion engines are at their maximum thermodynamic efficiency at maximum power, so the engine becomes a little more efficient at the power settings, BUT that efficiency is based on the amount of burned per horsepower. So while you're burning less fuel per horsepower, you're putting out more hp, so your total fuel burn goes up. Regardless, if my crappy old '06 is any indication, you should be getting low 40s at 75mph on flat terrain.

150 miles over 15 months likely does not meet the manufacturer's recommendation of 30 minutes per month, and it is the dealer's responsibility to document that. The dealer likely did not follow the manufacturer's recommendation, and your mixed-driving mpg and battery performance indicators support that. On that basis, you may have a claim for a replacement battery. I don't know anything about the Li batteries, but I suspect that Honda can measure the degradation of the battery pack with the diagnostic tool in much the same way they can the Ni-MH batteries. If your battery shows significant degradation, it should be replaced.

 

Like Michael said (and I read up on this before I bought my 2003 3 weeks ago) letting a hybrid sit for 15 months will TRASH the IMA battery. If your car is new take it back to them and have them replace BOTH batteries. If they won't do it, let it sit there till they do it and/or call your Honda district rep.

As for your bad mileage you ARE driving like a nut. Especially if you think (and you obviously do) that "doing an average of 75 mph" isn't abusing the car. If you have to drive that fast to get where you're going why don't you leave the house 5 measly minutes earlier?????? Then you won't be an accident looking for a place to happen.

Letting ANY battery sit idle or not on a charger for 15 months will drastically degrade it's lifespan - if not totally kill it. The only reason a new battery can st that long is that they don't have any acid in them yet. As for an IMA I don't know about their composition, but I do know that it won't do them any good to sit.

 

After driving for well over 45 years and seeing all those led-footed driver go by everything on the road I KNEW I'd see one of them on a forum some day, wondering why they got crappy gas mileage out of their car!!!!!!

His next complaint is going to be: "I was driving my new Honda the 350 miles from Vegas to L.A. last week, and guess what - the engine just BLEW UP!!! Yep - averaged 80 mph all the way there!!!"

A day later the dealer plugs his scan tool in to the car's black box and...........well you know........so much for that drivetrain warranty!!!!

 

rodbuilder,

Speaking ONLY of NiMH cells, there is evidence that deep self-discharge of these packs and/or sticks is actually beneficial provided cell reversal doesn't occur. I bought a pack from rossfree on this site, and it sat for about 2.5 years as-removed. The pack voltage was 59.6V (0.45V/cell) as-received. He removed it due to excessive recals and an IMA light.

I cycled them 3 times and discharged at 11.5A... there was no improvement from cycle to cycle, and they were at 90% rated capacity. That pack is now working in a car and hasn't thrown a single recal since the initial 12V terminal disconnect/connect.

eq1 over on Insight Central has recently tested sticks that sat for a couple years, and their capacity improved significantly as did their internal resistance. The longevity of these deep self-discharge cell is unknown, but things are looking pretty good at my end.

I have also fabricated 22 zener diode circuits to continuously drain the sticks as the chemistry catches up. I call this my "trickle discharger". I was getting tired of voltage rebound with repeated short drains. I took an 18 Ohm resistor and a 4.7V zener diode (both 5W) and shorted the terminals. After about 24 hours, the stick voltage sits at about 3.6V and will hold there for another day. I immediately recharge after that. I have recovered sticks that tested 4200-4300mAh to 5400-5500mAh.

Again, the longevity is in question, but initial results are very promising.

THAT SAID, the car electronics are ill-equipped to handle this situation, and IIRC, the 2013 uses a Li-ion pack, so I don't know that there's any value to grid charging. For a NiMH pack, excessive sitting can be easily corrected with a 24 hour grid charge.

Steve