Howdy folks, been a while...

My 99 7.3 seems to eat Batteries....for years I have to drop in 2 new ones about every 2 years.

I've always used the motorcraft from the stealer.

Question one: anyone else have this issue?

Two: what batteries might be better?

I have searches a few times for the drain with no success.

Low Battery issue started again late spring this year....been able to nurse it along as long as I drive everyday. But if I miss a day it's a jump start.

Thanks for any suggestions.
DL

 

Have you considered keeping it on a float charger? I don't notice a problem with mine, which I rarely drive, because it's always on a float charger. I have about 2.5 years and 8k miles on a pair of nothing-special batteries (I think 2-year warranty) from the local auto parts store.

 

Typically when someone is chewing through batteries like that there are several things that should be looked at, cleaned and inspected.

- Grounds to include major chassis and 2 main block connections
- Alternator efficiency
- Alternator B+ terminal and cable
- Battery terminal connections
- Battery wiring for corrosion
- Starter terminals
- Starter efficiency
- Starter relay on passenger fender (earlier trucks)
- Starter relay wiring and connections
- Parasitic drains

 

Interstate batteries from Costco's are a popular cost effective battery. Can/do you monitor your charging levels? Could your alternator be overcharging your batteries? That would take its toll over time.

 

How often do you drive the truck and how long are the drive cycles? LA batteries do not do well when put to bed without a full/near full charge which you won't get with short drive cycles.

 

I'm a real believer in the battery tenders mounted under the hood with an exterior plug. I think most 1999-2003 alternators do not do a good job of keeping our batteries charged. I now have a rebuilt 6.0 (large body) alternator from a local alternator shop along with a dual battery battery tender. I think this combo will extend the life of my batteries. The 6.0 alternator shows 14.1 volts at idle and will range around 14.3/14.4 on the road. I do not have any serious accessories that would require extra volts/amps, just batteries that didn't seem to last as long as they should have. I also like swapping the driver's side with the passenger's side every year or so as I have seen the passenger side (I think) die before the other side. All this is based upon observation and experience with the batteries and alternators. You must have the battery cables, clamps, etc. in top condition for the above to be true.

 

What batteries are they selling you.. They have two different ones I found.. You want the 850 CCA, but they usually sell the 750 and these trucks are tough
on them.

 

Not sure how much you drive but mine was a daily driver. I had an issue that killed batteries in less than 2 years and it turned out to be my starter. I don't know how or why but that fixed the issue.

As for batteries I have used sealed batteries for 15+ years. I do a lot of off-roading and I don't need the spillage. I used to use Optimas but my last set did not impress me much. I switched to North Star and loved them. The truck could sit for weeks and it would start like it ran the day before.

I also had the larger 6G case alternator like AubieTN. I had dual alternators and upgraded to 140A units and never had an issue again.

 

Better batteries aren't going to help much while having a drain and that drain will start damaging new batteries so you should solve that first. With a big drain, which this seems to be, I'd start by checking the alternator(s), disconnect the big charge wire and check between it and the cable with an amp meter. When they fail the draw is often enough to get a spark by tapping the connector to the post so you may not need a meter. The wire will have power so be careful not to touch it to any grounded metal parts, and while disconnecting it make sure your tool doesn't touch it and any grounded parts at the same time, the spark will be huge and can cause damage.

If that's not it, continue checking. With charged batteries; put an amp meter between one battery's negative post & cable then disconnect the other battery's negative and note the reading. Then start pulling fuses one at a time 'till the drain drops and that'll tell you which circuit is the culprit. You'll have to have the door open to get to your fuses which will turn on the dome lights and skew the reading. You can close the door latch with the door open to kill the lights. It can be latched with your fingers, but a screwdriver or other small diameter tool makes it easier, remember it's a two stage latch so you gotta close it to the second click. Also, I say to install the meter before disconnecting the other battery because sometimes the draw will be through a relay that'll deactivate when you remove power from the system.

The most common 'hidden' culprits I run into are glove box or vanity mirror lights staying on. Dome lights staying on is very common, but usually doesn't go unnoticed. Also, I've found some power adapters (things you plug into the cigarette lighter/power ports) that draw a lot of power even when nothing's plugged into them so if you have any you leave in place check those while your meter is connected.

 

I've been had by the cigarette lighter accessories getting me. Some have a light that stays on so I make sure not to use one of those. Took me a few days to figure out...but easy fix.

 

I don't think the light is what does it, mine draws very little, but maybe on some they draw more. I've heard some of them just draw a stupid amount of power for an unknown reason, and maybe they can become defective and draw too much. One of my friends recently had one turn his wiring crispy because it developed a short, but not enough of a short to pop the fuse, so it just slowly cooked the wires. I had one stop working recently, the light still worked, but no output.

 

installing new batteries at Walmart.



battery cable to drive side through 200 amp fuse and YES that is a new S&B air filter assembly..


when your truck is running the voltage at battery should read 14.1 to 14.3 if you are less then the alternator could be going bad.. On my 03 the batteries i bought the truck with in '15 were put in the M month of 2011 which is 12/11. I replaced them this spring with two new date code walmart 850 CCA guys. Now the alternator was rebuilt but local company in Va, Beach VA in the past so that could be a lot of the reason they lasted so long. plus during winter I keep a harbor freight trickle charger on it as i don't get a change to drive it much.

When i am at idle the plug in USB which has a volt display show 14.1 and at speed can show 14.3. I also have a separate battery wire from alt to driver side battery as well..

 

I have wondered what kind of draw those USB chargers pull. I have two of them plugged in and one is a system voltage display. It made me a little leery at first just leaving it plugged in but I thought logically it should not be drawing much at all with nothing charging off of it and they don't seem to create heat. My truck is usually driven very regularly though, which I assume helps with battery life.

 

Chinese made crap.