Same here--I have been fighting with the longevity of the FIT OEM batteries since I bought the FIT new in 2015.
They don't last long on this car.
On my previous 2009 FIT the batteries lasted an amazing long time.
I have all my service done at the Honda Dealer and they don't have a solution except to replace the battery.
The service manager once thought it was a never used aftermarket dealer lot alarm wiring that was on 2015 FIT and ordered that his techs strip it out to solve the problem but that did not help.
I just replace the battery every 2-3 years when it gives out.
Honda gave me 2 of the 4 batteries for free because I am a good customer of the dealership and the batteries expired too soon.
The last one cost me $140 and they installed it for free.
I am on my 4th Honda OEM battery since 2015.

 

Have you posted a complaint on the US NHTSA Recall website: https://www.nhtsa.gov/report-a-safety-problem . If enough people post a similar complaint, Honda has to officially open an investigation and drive to root cause. That's how recalls start.

 

Ok, I tested the new battery on the 2016 Fit, and it started at 14.2 volts and went down every day till it got to 11.1, and I put the trickle charger on to keep it from dying. Now interesting it the 2015 Fit is now holding the charge with the 100 thousand mile Honda battery, but we also use it daily, so will have to let it sit to test it. The dealer still insists I have something that is not standard that's causing the drain, and saw I have a GPS tracker that was added by the dealer when I bought it, that for some reason that they failed to disclose. I don't think that has anything to do with it, but will have to find where its hidden and remove it as the mechanic didn't show me where it was when he checked it. I don't think he thought it was the issue either, he just told me as a afterthought after testing it.

 

Well looks like it might be the IMMOBILIZER... https://www.fitfreak.net/forums/3rd-...onda-fits.html

 

You need to stop blowing money at the dealer and take it to a real technician. Dealers push hours, not diags- I've worked with some. Any good tech worth his weight will tell you, 4 mile trips is not what I'd consider enough to return your battery to full charge status. Depending on the system a minimum of 15-30 mins of run time is enough to give the battery a proper float voltage.

That being said these systems do have ELD so whilst running you will see 12+v and 14+ v at different times pending your alternator is good. DYOR if you don't know what that is, it's a good setup.

Third, you may have a slight drain. The charging systems on these have much to be desired and I do have times where the auto lock for driving is very weak, especially after just starting the vehicle. Heck even sometimes after driving a bit I can tell a difference. I don't put much stock into these systems.

So A. Find a real tech, rule out a draw (ideally you can do this yourself rather easily).
B. Take longer trips exceeding 15 mins.
C. If you really want the nitty gritty, run an ammeter to see if the math for "charge time" checks out. I'd do all of this for your proposed law suit as it would prevent the need for having to hire an EE expert witness to justify your case. 4 mile trips are not enough, and Honda did a good job not fast charging these batteries if it's the case.

 

Down here in Florida, you take it to a dealer or you get problems as most of the new mechanics have no clue or cant fix nothing on the new cars, as the parts have to be changed not fixed, and guess who has the parts....

I used to have a personal mechanic but he retired and the others were in Miami which is a bit of drive now...

 

Same here in Los Angeles. I always go to the same Honda Dealer for service. Over the years the times I tried to save some $$ and go to two different independent shops, the work was mediocre, they tried to sell me things I did not need, and they break other things and deny it. At the dealer, work is not always perfect, but if I point it out--they re-do it immediately and usually compensate me with future service credit. The Honda service manager confided in me that in my area the cost of living is so high that both Honda Dealers and independents have a difficult time attracting and keeping quality technicians at the wages they can pay.

 

That sucks. I know it's an issue here also.

The only way good techs are going to stay is to be given tools + training and not treated like garbage/ripped off with warranty times, or go with a different caliber of people altogether - the real solution. But that is a ship that needs a large force, and it just won't happen-likely.

I'll preface this saying it's not my job to solve it- I don't want to solve it, honestly. I make good money because of it. Regardless, dealers out here for example charge $160-$220/hr (per Toyota and Chevy respectively), but techs are down in the 20-25/hr range, benefits are about double that. Math just doesn't make sense. In an independent shop- maybe- for a dealer, absolutely not.

I know the dealers make money also. I once had a customer who had a friend who was a corporate lawyer. Long story short, dealer ripped him off- he tried to remedy- dealer said GFY- he bought a billboard up the road stating the facts and the dealer paid out 3 or 4 new vehicles- one being a brand new Corvette, what was undisclosed but may have been 3-4 million-nobody knows as they say, and they even agreed to buy the billboard's contract for 36k. So they have money, they just don't want to pay it. I even offered subcontracting services for an indy shop/dealer at $40/hour, They were charging $60-which I doubt because they would have had so much work their shop would have halted, but they turned down the $40/hr contract agreement, pricing the only issue. Tried me at 25 to contract but that's a slap to the face. EV is going to be lengths worse should it be forced.

 

I think I am getting a clue on this. As I said I have two Honda Fits, and so no matter what the Immobilizer appears to be getting activated by the key fob from the other Honda Fit. So in other words, I can leave my 2016 Honda Fit EX locked up and sitting for a month or more without opening or coming by with the key fob for the 2016 Honda Fit EX. But unfortunately, I am coming by with the key fob for the 2015 Honda Fit EX, so it appears to be activating the 2016 Honda Fit EX Immobilizer system and thus draws down the battery.

I left my 2016 Honda Fit EX unlocked, and the drain seems to stabilize or disappear altogether, as I had a trickle charge on it all the time, it was hard to figure that out. I took the trickle charger off and left it unlocked, and its been stabilized around 12.5 volts on the meter, right where it should be. But if I lock the 2016 Honda Fit EX, the battery starts to drain, even if it is not near the 2016 Honda Fit EX key fob, but only come by it with the key fob for the 2015 Honda Fit EX to open and start the other car. Bottom line, the Immobilizer seems to activate if any key fob for a Honda Fit EX comes near, and thus put a drain on the battery of any nearby 3rd Gen Honda Fit. My question would be, what activates the Immobilizer, any key fob or a Honda key fob or just those specifically for the Honda Fit, any one know?

 

I don’t think any else knows more than you at this point, except the engineers that designed the system.

It seems that the alarm is listening for a specific radio protocol, which in turn activates something while the car is locked (the capacitive handle sensing, maybe?). I imagine this radio protocol is limited to recent generations of Honda key fobs

Best of luck

 

The immobilizer is strictly to do with securing the engine from hot-wiring. The issue at hand is likely to do with the Keyless Access system and/or the associated security system. I'm not sure what it's doing while locked that's so power hungry, but it makes sense that the system could go completely dormant while sitting unlocked - it doesn't even need to watch the door handle touch-pads. Keyless Access is likely using some variation on near-field communication, similar to RFID tags. While locked, it might be pinging for nearby keyfobs, to speed up the verification process when you touch the door handle? The slight delay between touching the door handle and lock(s) actuating always made me think it was the other way around - touch wakes up the system, which then pings for a keyfob, does a secure handshake, then unlocks the door. Maybe early versions were too laggy, so Honda took a more responsive but power-hungry approach?

 

I added a costco interstate 51r and it lasted for nearly 5 years, replaced it with the same less than 6 months ago, but then had power/starting issues. I'll spare y'all and myself the long twisty story of my experience chasing the issue, but an auto shop determined it was the battery and claimed Costco Interstate batteries are not manufactured the the same quality as non-Costco batteries so he sold me his for a pretty penny. Everything has been fine since.

 

Uh huh. A company renowned for its accommodating return policy is selling junk batteries, or an auto-shop is looking for a reason to price-gouge you on a battery sale. I bet you had a loose battery terminal.