OT Battery trouble

2002 Ford Explorer: Has 2 Y.O. NAPA battery w/ 5 year warranty. Cost about $110. All works OK during summer. Now, colder, battery goes dead if vehicle sits for several days. It did the same last winter. Took it back to NAPA, they tested it & say nothing wrong w/ it. Alternator puts out 13.8 v. I checked current drain when all shut down & measured about 10 ma. I still think there is something wrong w/ the battery. NAPA guy says cars have to be driven regularly in order to keep battery "up". I say nuts to that. I have stored collector cars (w/engine computers)for 8 months & they start right up. Anyone else have similar experience? What is going on here?

Unhook the battery when it sits and see if it starts then.

There are many newer cars that will kill a battery in 6 weeks if they aren't started. NOT a couple of days though. And 10 MAs is nothing. The fact that you've let some sit for 8 months doesn't mean a thing though. Different cars with different options have different current draw demands when parked. My 98 Dodge Caravan will kill a battery in 6 weeks like clockwork if I don't keep a battery maintainer on it OR turn the battery off. It says that right in the owner's manual. My 99 Kia Sportage about the same. On the other hand, my 2002 Subaru can sit much longer.

Besides whatever drain your ECM and/or alarm draws all the time - a battery also discharges all on it's own.

A standard lead-acid battery loses 2%-30% of it's charge every month when not hooked to anything. The more antimony in the plates, the faster it loses its charge. So, the more HD the battery is, the faster it loses it's own charge.

Most standard-equipment car batteries lose 5% per month.

Alternator needs to put out 14.6 volts to fully charge battery. Replace alternator, problem fixed!

While many modern cars still draw very low current when setting (electronics), that 10 ma dont sound like much and I dont see that as causing any rapid discharge and even with no load batteries eventually self discharge. There may be a high resistance internal short yet she still load tests pretty decent, I like the other posters method to disconect it when she sets a long time n see what happens?? The shop can do a load test and check specific gravity but if all that passes yet she continues to fast self discharge there must be a "battery problem" of some sorts.

John T

13.8V is very low to recharge a 12V battery, should be atleast 14.2 with 14.6 being pretty common.

Recharge the battery, then start it and let it run 5 minutes before doing another voltage check at the battery posts with the engine running atleast 1500 rpm. If it still is below 14.2V, you have an alternator problem.
Voltage before starting the pickup with a good fully charged battery should be 12.6 volts, check that first to be sure the battery IS OK.

No they don't have to put out 14.6. Many computer regulated charging systems keep the voltage under 14.

Napa guy needs to take care of his customer and warranty the battery.

Computer regulated or not, your not going to change the fact that a lead acid battery needs atleast 14.2 volts to recharge in any reasonable amount of time, especially when the battery temp is below 70F.
Most of the automotive Delco SI series alternators with internal solid state regulator are set right at 14.6 volts. Most other brands are very close to that number.

These things can drive you nuts, and sometimes the answer is something you never expected. Once I had a Crown Vic that the battery was forever running down on, slowly over a period of time. New battery, same problem. I was constantly re-charging.

One night my small daughter, riding in the back seat, said "What is that light for?" "What light?", I responded. She pointed to the glove box. Turns out that switch on the glove box wasn't killing the light when the lid was closed. Bulb removed, problem solved.

(quoted from post at 18:21:41 11/27/11) Napa guy needs to take care of his customer and warranty the battery.

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If the battery test good then where is the warrenty?


Disconnect the battery, put a charger on it and fully charge it should be about 13.8 volts. Let it set a few days disconnected and test the voltage, if there is a big drop in voltage there is a battery issue so take it to a shop you trust and have them test it. Pull the alternator and have it bench tested. It isn't putting out what it should as someone else pointed out.

Rick

Couple things:

1) I have a 05 Chevrolet pickup with a 4.3 V6 (I know, I', comparing apples to oranges here) But in roughly 14 days time the battery will be quite low.. In 30 days time, get out the jumper cables. Has done it since new in Novenber 2004, nearly 150k ago.. It had a new NAPA battery last year, seems to take a little longer to draw till dead now, but still does, winter or summer, don't matter.

2) Last winter, I fought the fight with my local NAPA about the batteries in my 86 Ford diesel.. If I drove it every day, and cycled the glow plugs only once, it would fire off fine.. Otherwise.. it was a no go.. 30 seconds on 200-amp boost and off we'd go, and it'd be fine the rest of the day.. Took batteries (in truck) to the napa, tested them, again, in the truck, and seemed to be fine.. Waited until the morning it wouldn't start again, pulled the batteries and took them in.. One ended up having a bad cell.. Replaced under warranty.. Happy customer I was.

3) BOTH my 05 Chevy and my 86 Ford charge closer to 14.5 volts than the 13.8 range.. I DARE TO BET if you ramp the truck up around 1500 r's, kick the lights on, and the blower fan on high you'll be lucky to charge at 13v.. Then I bet you'll have a rally good idea what your issue is..

Unless you've trouble shot all possible scenarios, it's hard to blame that battery, but again, you could have a battery issue.. Before you jump to conclusions and start war with the parts house, trouble shoot all other possibilities out.. Don't be like my dad and throw parts at it until it's fixed.. (3 starters, a alternator, and finally a replacement battery in a 8 year old truck to make it start and hold a charge.. But hey, I'm just a kid, what the heck do I know.. I know if the battery is junk no alternator will make it hold charge, and no starter will work with a dead battery)

Brad

(quoted from post at 21:54:27 11/27/11) Couple things:



3) BOTH my 05 Chevy and my 86 Ford charge closer to 14.5 volts than the 13.8 range.. I DARE TO BET if you ramp the truck up around 1500 r's, kick the lights on, and the blower fan on high you'll be lucky to charge at 13v.. Then I bet you'll have a rally good idea what your issue is..

Unless you've trouble shot all possible scenarios, it's hard to blame that battery, but again, you could have a battery issue.. Before you jump to conclusions and start war with the parts house, trouble shoot all other possibilities out.. Don't be like my dad and throw parts at it until it's fixed.. (3 starters, a alternator, and finally a replacement battery in a 8 year old truck to make it start and hold a charge.. But hey, I'm just a kid, what the heck do I know.. I know if the battery is junk no alternator will make it hold charge, and no starter will work with a dead battery)

Brad

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Bet ya that with the blower and lights on at 1500 RPM's the alternator will be putting out 14.6......if it didn't your battery would go dead while running. Thats what the regulators job is. To increase the amp output to keep up with draw. The lights and fan motor require 12 volts to operate but they draw amperage to run.


Good point about no starter will work with a dead battery.....LOL I like that! Another good point for a young person reguarding fuel.....if ya keep the top half of the tank full the bottom half will never run empty (advice I got and have followed when an old guy helped me out many years ago when I ran out of gas).

Rick

My Ford pickup did the same thing,glove box switch stayed on.Trunk lite in my wifes 85 chevy was on full time.The car was ok during the week but wouldnt crank on Monday mornings.I checked the under hood lite first, ok .Opened the trunk, touched the bulb, hot as a poker.Door switches let the interior lights stay on on often.Over the years I found brake lite switches the left the lites stay on.

You should see 14.5 volts when measuring your charging voltage across the battery terminals. If you have an internal regulator it may be causing the battery drain and the low charging voltage. Do what's been suggested and disconnect the battery ground
and put a trickle charger on it overnight. If you can let the battery sit for several days then see if your battery will start the engine. If it starts ok I would have the alternator checked. Hal

Two things:

The newer computerized vehicles do have a small continual "drain" ('bout 7ma) on the battery to keep the memory alive. However, the battery shoudn't go south in just a few days.

Second, your alternator isn't putting out nearly enough juice (minimum of 14.2 with a fully charged battery).

Alternators are "usually" the source of a larger drain. I.E. the system just can't keep up with the added load of colder weather.

Not saying your battery isn't t!ts up, but I'd sure be looking at that charging system.

Allan