2016 RDX with tech pkg, 80,000 miles. Battery died and I purchased a AAA battery six months ago. That battery died and AAA just replaced it under warranty. A few days later that battery was dead so took to dealer to check for parasitic draw. They replaced AC relay and said I was good to go.
Six days later battery is dead so I returned to dealer for testing. They put system to sleep and checked for issues. They couldn’t find any problems and said battery and electrical system checked out. 24 hours later my battery is dead.
I’m wondering if AAA installed the wrong battery and am considering spending $300 for an Interstate AGM battery. Any thoughts about this issue?
Thanks for your ideas.

 

There is a known issue with the Hands Free Link (HFL) module going bad and draining the battery. Worth having that disconnected for a few days to see if the problem goes away. Tale a look here for location: https://acurazine.com/forums/second-...x-tech-994113/

 

Check your battery cables and make sure they are attached firmly to the terminals. A loose clamp will cause the issues you are experiencing.

 

Thank you for the info and links. I may try and disconnect today if I can get the panel off. I had read about this issue here on the forum and asked the Acura service manager to make sure they checked the HFL module. He said they tested and it checked out ok. I think it’s still worth me having a go at it though.

 

I checked the battery cables for tightness, located and disconnected the HFL module. I charged the battery and drove the car for 45 minutes yesterday afternoon.
20 hours later the battery is dead and there is a strange clicking noise coming from the dash area. The noise stops when I push on the brake pedal or push the start button, but the car is dead, no interior light's etc. Another odd thing is when I opened the door yesterday, all of the windows and sunroof opened. The key fob was in the house so I know I didn’t inadvertently push the unlock button. Any ideas about the clicking sound or what my next step shroud be? Thanks again for your help!

 

Sounds like you definitely have a component that's draining the battery. This will be tough to troubleshoot. Either take it to a good mechanic who specializes in electrical problems, or you can charge the battery, and put a tester on it. If the tester shows drain with the car off, start pulling fuses one by one until the drain stops. Then you will know which circuit is the culprit.

Interesting videos that might help:

 

sounds like your buttons are pressed down on the remote. pull the battery on the remote and try again

 

Thanks again for your help. Looks like this may take awhile to solve. I did disconnect the battery overnight after charging yesterday. Battery seemed fine this morning. I will see how long it takes to drain it now that it’s reconnected.

 

Thanks, good idea! I’m checking that now.

 

I recently had to add a shim to the positive terminal on my 2018 RDX (could no longer get a solid grip on the terminal, and was losing connection), and this morning, about 6 weeks after installing the shim, which remains solid, the RDX wouldn't start.

I've got a charger on the battery (slow, as it's only 1.5 amp, intended for a motorcycle), but I noticed it is not only an Acura branded battery, but has a sticker marked 11/19.

In an abundance of caution, I ordered a new battery and new battery cable to replace the current positive terminal.

Is this is common issue with these 2nd gen RDX's? If it's a 2018, my guess is that the original battery was replaced after about two years, and this one about 26 months.

Curious as to your thoughts that there can be a slow drain I'm missing. Car is driven heavily, with mixed long and short rides, so should be plenty charged. Any thoughts appreciated. I'll update once new battery installed and let you all know if there is a continuing problem... hoping it will resolve.

Thanks,

-Dan

 

OP - I would say that you definitely have some sort of parasitic drain. You mention hearing a strange clicking noise so that means something isn't shutting off when you turn off your RDX. We have a 2016 RDX Advance that we bought used in 2017 (5 years ago last month) and as far as I know we still have the original factory battery. It's definitely OEM, I just don't know if it was replaced during the first year of ownership. We have just under ~80K on the odometer and to date have had no issues.
As already mentioned the HFL is/has been a known issue in the 3G TL and I believe the RL. I am/was unaware it has been an issue in the RDX, but I suppose it could be. Another known issue and parasitic drain in the 3G TL is a faulty AC relay so they do happen. Some diagnostic work either on your part or that of a good mechanic should be able to figure it out.
Lots of members here on Azine are not fans of the OEM battery, say they don't last and we may be on the other side with longer than usual life, but you shouldn't need to be replacing your battery that frequently.

 

The RDX went back to the dealer for the third time. They requested that I leave it for a few days so that they could thoroughly check electrical system.
They called and said they were certain that it was the keyless access/tpms control unit failure creating excess draw when vehicle was turned off.
They replaced the unit and reregistered the keys. Tested battery and reconnected the HFL module. Repair total $1163. I drove the car home Monday afternoon and just now discovered it dead in the garage. At the first visit they inspected and replaced the AC compressor relay for $226, this is now starting to get expensive, especially with the problem unresolved..
It’s a 90 minute round trip journey to the dealer and I don’t have confidence that a fourth trip will yield better results. At this point I would like to get a full refund from Acura and try to find an independent shop and see if they can figure this out. Any suggestions would be appreciated. Thanks much.

 

Sorry to hear of your frustration. Dealers seam to easily "dupe" themselves into believing their "diagnosis" -- without making any attempt to confirm it (e.g., dealer telling me the noise in the ass end was caused by spare tire; if so, REMOVE spare tire and verify noise leaves with it! Ooops! I guess it was a bad shock and not the tire...). This doesn't inspire confidence in the thought process of their techs!

Note that a modern car is never really "off". And, the things that are running have a mind of their own. I.e., a load can come on any time the car decides to power it up!

You can make sure you don't leave anything near the car that can "tickle" it. E.g., key fob or anything else that emits radio waves (that the car would have to evaluate to determine if it is supposed to react in some way).

So, you really need a sort of "data logger" to watch your power drain, over time. Or, sit and watch a meter "overnight" (no doubt you have better things to do with your time!).

Sadly, I've been scratching my head and can't think of anything that "Joe Average User" could apply to the task, given that we don't know when the drain can manifest, in your case (something less than 20 hours?) and how long it will persist (is it on for a minute and off for 10?).

Can you, perhaps, park the car at your neighbor's house (or some other place that is NOT your normal site), instead? I.e., to put some physical distance between it and your "lifestyle" -- in case there is something in your home that is tickling it?

Short of that, you can possibly start pulling fuses for "nonessential" items that you KNOW the car doesn't need to access while parked, overnight. This would help eliminate the possible culprits.

 

Thank you for your thoughts and suggestions. Acura said yesterday they were certain that it’s my battery causing my grief. AAA came out in the afternoon and carefully inspected, cleaned terminals and tightened down the battery since Acura failed to do so. Tech told me to drive for an hour to charge the battery and if it died again they would replace it under warranty. Next step is to start pulling fuses and park the car outside for a few days. It’s a bummer because this RDX has been a great car for six years.

 

My bet: if the battery cable was not tightened down, AAA fixed your problem by tightening it.

 

I wish that were true. The cables were tight but the battery itself had not been cinched down. AAA tech is on the way now as the car is dead again. Their dispatch just said that AAA does not sell batteries for the 2016 RDX and that I will need to purchase elsewhere. I wonder what the last tech installed as it is clearly marked as AAA battery. I would have thought that Acura would replace the battery as part of their diagnostic process.