Patches

I installed a Red Top in the wife's C5 shortly after buying it 2.33 years ago so it's been in almost 2 years. For the past several months, the battery has died a few times when the car was left sitting for more than a couple of days. Now, I know the hatred and angst associated with the Red Top here on this forum, but I've had one in my other C5 for ~7 years (on a Battery Tender since it's a garage queen) with no issues.

I decided to put Bill Curlee's vast intellect to work and used his current draw test procedure to vet out any unauthorized electron-stealing processes going on under my nose in her electrical system. I connected my DVM in series with the negative cable and post on the battery and set it up to display current in the range of 0-10 amps. Initial current spiked to 7-8 amps and quickly settled to 0.29 after a minute or so, then finally to 0.22 after a good 45 minutes of monitoring.

After a minute


After 45 minutes


This is definitely too large of a current draw to expect the battery to survive unattended for very long. I thought back to all the mods I've done since installing the Red Top and the one that immediately hit the "Suspicious" button was the Garmin Nav unit hardwire mod I did almost a year ago.

So, I reached in and unplugged it. The amperage, of course, suddenly spiked to 8 amps since I "woke" the BCM up but, after several minutes, the current settled to 0.04 amps or 40 milliamps which is very close to Bill's recommendation for a trouble-free charging system, taking the resistance variation of systems into consideration.



That's 5.5 times less current draw than when the Garmin is plugged in. Realize that the Garmin was fully charged and off/in sleep mode during the initial test when it was still plugged in. I imagine it would be significantly higher if it were in full charge mode with the ignition off. I will continue to monitor the battery condition and look for more of those pesky current burglers now that I know it's always a potential issue.

Blue 92

With the Garmin off you'd think any load would be negligible.

Patches

Apparently, the Garmin draws a nominal current even in fully-charged sleep mode even when off.

I had bought the wife an emergency battey starter to keep in the car just in case which I'm leaving in there until I've verified that this is the only parasitic draw on her car. I'm thinking of checking my coupe as well just in case.

Bill Curlee

Well done!!!!

BC

Dave68

That's good info to know. I would guess that the two no-start conditions means a shortened battery life. I estimate that for every "big drain", a typical battery loses about 3-4 months of its life. Also, from what I've gathered here on the forum, AGM batteries are particularly susceptible to having their lifespans severely shortened after being allowed to drain for one reason or another. The reason why I'm mentining this is that you might want to replace her battery long before 7 years rolls around.

Dave

Bill Curlee

Dave

I bought my 97 F150 in late 96 and just sold/traded it in on an 08 Jeep back in Feb. The battery in the truck is the origional Ford Motorcraft battery. I ran it down to DOOR NAIL DEAD twice and it charged right back up with no apparent issues.
So,,,it was 12 years old when I traded the truck!

The OEM Delco in my 98 lasted 7 years before I caved in and pulled it out because I was afraid that it was going to leak!

I guess Im good with batteries.

Bill

mcgilles

good catch! I try to unplug all that stuff when I park the car, now I'll pay even more attention to it. it could be just the charging circuitry in the charger. if the garmin runs off 5V there would have to be a converter in it (no idea what they actually use)

those little transformers that you have all over your house aparently draw about 60% of their nominal in-use current even if the device on the other end is unplugged completely! I was surprised to hear that but it make sense, the rectifier inside is still in operation even if there is no load. always a good idea to unplug everything when you can.

you should wire your garmin into the ACC circuit provided above the BCM so its only powerd when the ignition is on. if you need to use it otherwise you can always run it on batteries. how did you hard wire it anyway? sounds like an interesting mod to me!

killain

I have always had excellant service from a Optima Red Top, but I do have a little advice when using a Red Top, if your not going to be using the car for a number of days, use a battery tender or float charger. Optima Red Tops do not do well when allowed to go into Deep Discharge, then charged back up, but you never really get back the same level of original charge. If fact Optime, makes a battery if this is going to be the service environment, the Optima Yellow Top is designed to withstand deep discharge, and recharging. If I'm not going to use my 2003 for a couple of weeks I put the battery butler, float charger on the battery and it's alway crips when I need to use it.

Dave68

That you are, Bill!

I typically use Walmart batteries in my 89 Mazda MX6 GT. When someone in the family leaves the door ajar overnight, once or twice, the battery lasts about 4.5 years, but if there were never any large drains, I get 5-6 years out of the battery - not bad for a $60 battery!

Dave

Patches

I need to unplug her Valentine 1 and see if that has any effect also, although, not having a battery to charge probably negates any parasitic effect it could have.

Frenchican

Good info, thanks for the effort. I MAYBE... put 500 miles a year on my C5 with that has the Red Top. I usually put a 2 amp charge for 30 hours every few months. So these results are pretty right on for my situation.

Thanks,
Tommy

timemender

I have my V1 hard wired to the "switched" accessory wire on the harness next to the BCM. (yellow wire IF I remember correctly) That way I don't have to switch it off separately.

Patches

I pulled the traffic module/power plug apart and added terminals then ran it into the center stack and tapped into an always-hot power source with an inline fuse.







The non-dimming rv mirror I have it wired to doesn't have a switched power source. Not a big deal as that's hard to forget due to it's beeping when the car is shut off. I am considering running the wire to the BCM accessory connector.

jrprich

Re: Hardwire........I have my Garmin, my iPod, and SAT radio all hard wired to ACC feeds.
While Patches' method is beautiful, as always.....mine works fine with less work.
At any auto parts rack you can find those 12v lighter plug splitters.
I just cut off the two female ends and splice them to my 12v ACC source and use the OEM male lighter plugs.......held in firmly with some elec. tape. Works fine, plenty or room behind the ashtray section to house the taped adapters.
However I don't leave these items plugged in except when in use......SAT radio excepted.

Patches

Nice solution, Jim. But you know that if it wasn't painfully complex, I would be dissatisfied with the method. Simple often doesn't work for me.

jrprich

I understand......I just didn't want to toast my OEM adapters as I will want them in the future for resale when I upgrade.
Not to mention that my solder skills are lame......
My solution isn't pretty......but then no one ever sees it anyway.

Patches

Yeah, I ended up buying the wife a second adapter because she's so addicted to the damn thing, she takes the Garmin in her friends' cars when they drive.