AlanW

Wife had dead battery Wed night. I went & jump started it and figured/hoped that the wife had just left too much stuff running on the battery & drained it. Yesterday I cleaned connections & posts & charged it up. Battery charged up to 12.79 V and did OK driving around last night.
This morning, voltage was only 12.2 V.

Before I go buy a new battery, is there known issues with the HFL module draining the battery, like in the 3G TLs???
The battery was in the vehicle when we bought it, has a sticker on it showing 2/16, but it is one of those POS WalMart Maxx NeverStarts

thoiboi

You'll have to do a parasitic drain test to determine what's causing the drain

mrgold35

There is a +90% chance of it being the handsfree module draining the battery. The easy way to know is charge the battery to 100%, see what the drop in power is over time (like 8hrs over night), recharge back to 100% disconnect the handsfree module, and measure the drop of power over the same amount of time. I don't know if the +10 MDX hands free bluetooth module with audio streaming is compatible with the 07-09 versions if you can't fine the module in the 07-09 model years.

AlanW

We don't ever use the HFL in the vehicle. I'll try disconnecting it tonight and give the POS WalMart battery another chance.
When the HFL module went bad in the TL, I disconnected it and never really thought about again.

I'm guessing it is mounted in the roof up by the rearview mirror like the TLs?

Skirmich

^ Mine never failed but it rarely got used so I have a perfectly working HFL Disconnected in my X. I said better safe than sorry, Specially with an Optima Battery in there.

mrgold35

I think the module is located in the rear of the center console right behind the A/C controls for the 2nd row.

https://www.youtube.com/watch?v=hhesmDjyBx0

optimus prime

My wife's MDX had a bad drain issue. When off, car was still drawing over 4 amps. Disconnected the HFL since she refuses to use it anyway, drain issue is gone. Still debating whether to get a replacement since no one seems to miss it.

technocrat

Yes it is, a month ago I had this issue on 2011 Tech + ENT MDX, luckily I have extended warranty so it was covered.

The new module not sure is up-to-date mark as once I was hearing garbeled sound while talking over new hfl unit hasn't happened again so will see.

Also on phone the engineer told me that the cost to fix it would be some $490 and to just disconnect would be $120. Interestingly after confirming warranty coverage, when I picked the car the cost of HFL on bill(with zero payment required from my side) was ~$240. They couldn't explain why they quoted me almost double in absence of warranty.

AlanW

$120 jus to disconnect?? That's outrageous. I took me all of about 2-3 minutes to pop the back of the console off, unplug the module, and snap the console piece back on. Job done!
Battery is now reading around 12.4 V first thing in the mornings. Shouldn't a good strong battery read over 12.5V, more like 12.6 or 12.7??

thoiboi

How old is your battery?

mrgold35

My old OEM battery could range between 11.8v to 12.7v; but, the MDX would fail to start if the battery % got below the 35% reading on my battery charger. I had the alternators on my TSX and RDX fail, power drain in the RDX, and all three OEM batteries fail. They all seemed to handle that voltage range; but, all 3 vehicles really hate low battery capacity % (you get the X-mas lights on the dash, AWD limp mode, jerky transmission, etc...). A battery never seems to bounce back 100% once it goes dead. It might read 100%/12.7v fully charged; but, is could be down on its capacity and it might die on a cold winter morning if it doesn't start 1st or 2nd try.