I have an '07 Tl with 95,000 ish miles. Up until last month, everything was great! Here is what happened:

I drove to the office and right when i was parking, an error came up on the dash/navi. I don't remember exactly what it was but it said to check the charging system. I went to the office for about 2 hours and when i came out, the battery was dead. Tried to jump it but still no go. I ended up letting the jumper cables sit for about 10 mins then it started up. I drove it right to the shop and they replaced the battery.

All was good until i was driving home and everything started to systematically shut down until the car died. Towed it to the shop, they replaced the alternator.

All was good for a couple of weeks until i went out to the car on a thursday and the battery was dead. I jumped it and it started up. Drove around to do some errands with no problems, starting and stopping.
The next day, i needed a jump again. So i jumped it and brought it the the shop. It sat over the weekend and when the mechanic checked it on monday, the battery was dead. He charged it and let it sit until tuesday afternoon. it started up no problem. He said it was probably just a one time deal and i picked up the car on thursday.

i was good for a week. Now if the car sits for more than a few hours, I'll need a jump. After some research on here i found a thread saying the HFL might be the drain, so i disconnected it. The battery is still draining. Are there any common circuits that are know to cause drain? what if its not the HFL but something else on the circuit, what else is on the circuit with the HLF?

 

Have you put in a new battery after changing the HFL? I had the same issue in my MDX and I had to buy a new battery since the old one would not take load from being drained and charged like crazy.

 

The battery is only 2 months old.
The alternator came about a month after the battery.

 

Are your battery cables corroded?

My car left me stranded before, after work one time, and at a gas station another.

Just no power to start the car.

Replaced the negative cable, 32600-SEP-A00 and it's been around 3 years now no problems.

 

The cables look good. The mechanic cleaned them up a bit when he changed the battery. They are tight too, not a loose connection.
I was thinking it might be a connection issue because when i jumped it last night, it started quick. I hooked up the cables, alarm went off, sat in the seat and started the car. The cables weren't even on for 10 seconds before i started it.

 

Based on the information you provided, specifically the tidbit about your vehicle's electrical system losing power while you are driving, it definitely appears your battery is not being charged by the alternator or possibly a short occurring somewhere in the wiring. I'm not a betting man, but if I were, I'd place my money on a problem with a cable or cable connection. Here are a couple of places I would start with:

1) Check the ground cable coming off your battery. Remove the negative terminal from the battery, and with a ohmmeter, place one lead on the negative terminal and the other lead on a known good ground in your engine bay. The resistance should be ~1 ohm or less. If you are picking up high resistance, check the terminals at the wire ends to ensure they are not corroded/damaged/loosely crimped and ohm out the negative cable end-to-end to verify you still have the high resistance -this would indicate a break somewhere in the wire or a bad terminal end(s).

2) Verify the terminal connection at the alternator is not loose/corroded/etc. If everything appears to be good and tight, ohm out the entire wire between the alternator and battery with the cable disconnected at both ends. Ohm the cable from end-to-end (checking for high resistance) and from the terminal to chassis ground (checking for possible shorts).

Hope this helps.

 

You can always take your car to autozone and ask them to hook up the equipment they have to check the whole charging system if there is anything wrong or your battery might be just too weak to start on cold days from all this mess?

 

The car died while driving because the alternator failed. I replaced the alternator. I know the alternator is not the problem and i know the battery has charge when i first turn off the car. If i turn off the engine i can turn it back on again a few mins later, just not over night.

 

I should have read your first post more carefully.

In that case, you could perform a check to see if any part of your electrical system is parasitically draining your battery. There shouldn't be any more than a 50 milliamp draw from your battery with the vehicle off and in "sleep" mode. Here's a good wikihow:

How to Find a Parasitic Battery Drain: 9 Steps (with Pictures)

 

Sooooo.... my mechanic says he has found the bad circuit. He thinks that an AC relay is tuning on and off after the key is removed.

 

I recently went through the same crap with my 08 MDX. Disconnected the HFL. Charged the battery (brand new Interstate and Red Top) SSDD. I finally figured out that every time I would connect a fully charged battery, I could hear the click of the A/C compressor clutch engaging. When I finally hooked up a multimeter and pulled the fuse for the A/C clutch, I was drawing 4-5 amps.

I had the car shut down and didn't open any doors, etc when I ran the test. Sure enough, the fuse was fine, it was the relay that was bad. I picked up a cheapo relay at Autozone and that fixed the parasitic drain. Problem is, It also popped the pressure relief valve on my compressor. So I had to replace that and add a pound of refrigerant. That was about a $350 issue.

 

Replacing the relay is a band-aid. The compressor clutch and stator are bad, and it caused the a/c relay to stick. if the clutch/stator are not replaced, you will continue to have this same problem.