How long should batteries last?

[DennisG01]

Batteries sit on store shelves for months and still retain their juice, don't they? I'll hook up an ammeter to check draw, but shouldn't batteries last longer? Would the ECM, radio memory and whatever else that has a constant draw be enough to kill the batteries in a month? They are less than a year old - matched set, 900cca.

The last time I drove my truck was about a month ago. Today (about 40* outside and I plugged the block heater in last night), there was enough juice to unlock the doors, turn on gauges, idiot lights, etc. But wouldn't turn the engine - I got more than a "click", but not enough power to completely start to spin the engine. I didn't have time to do much else, I just hooked up a charger and went to work with the Honda - although I disconnected the crossover cable and for now the charger is only on the passenger's side.


How long have some of you been able to go without having to charge? Or, am I expecting too much?

 

[JMJNet]

Have you checked your alternator?

Also check the battery fluid.

Or you get a lemon battery. Challenge is it is probably only 1 of them is bad but you need 2.

 

[pgguru]

You should get more than a Month on 2 batteries. I would try to do a warranty replacement

 

[DennisG01]

About 4 months ago the alt was putting out 14.3 at the battery - but good point - easy enough to check again.

Glad to hear others think they should last longer!

 

[BigBlueChevy]

my optima yellowtops have been in my truck since 05' And they have never once given me a problem. Hell, I have so much power that people call me when there batteries die to jump them. There car starts after about 5 seconds of charging.

 

[Diesel -T]

Parasitic draw & Pennsylvania cold weather might deplete batteries over a month ,enough to prevent cranking ,but probaly a good idea to have them load tested where purchased to see if ok or defective . Need to be charged right up to test.

 

[packratt]

Also have you cleaned your grounds and the hot wires at the battery. Remove the spacer and make sure that the actual terminals on the pos wire are clean and free of insulation. The plastic sheath on mine was actually covering part of the terminal.

 

[DennisG01]

Also have you cleaned your grounds and the hot wires at the battery. Remove the spacer and make sure that the actual terminals on the pos wire are clean and free of insulation. The plastic sheath on mine was actually covering part of the terminal.

Yes, in fact all cables are brand new - bigger cables, bigger and more grounds - as of about 10 months ago when the engine went back in. Everything is nice and shiny - both front and back sides.

I've had the one battery charging all day. I'll try starting her up when I get home. I'll put the other battery on charge overnight. I'll run it tomorrow -- gotta go pick-up a small flatbed to transport my boat engine, anyways. I'll then check for current draw - and again check alt output. I'll get the batteries tested, as well - just to be sure.

 

[packratt]

Check and make sure it is not feeding back through your alternator. Get an amp meter. Remove one of the battery cables. Put amp meter between cable and battery terminal. As you know you have a drain it should be showing a draw. Unplug alternator. If draw is gone you have a bad alternator. The diodes going bad will not always show up on the diagnostic computers. Had a $20,000 Sun machine tell me my alternator was good but the $25 multimeter told the truth.

 

[Matt Bachand]

I'd be happy with a month but thats me. In fact, even if i let a vehicle sit a month i'd put the batt charger on it before start.

Of course i'd EXPECT the dome lights and stuff to come on their own. not be flat out dead.

 

[mitchedo]

My 91 Suburban can barely make it a month without being started. My 78 Scout and 67 Chevelle can sit for upwards of a year and still crank themselves to life. Therefore, I conclude the computer and other electronics (like the radio) put a small draw on our vehicles and destroy batteries on seldom-driven vehicles.

Once you run a lead-acid battery completely dead, you usually have to replace it. Lead acid batteries don't tolerate being run completely dead.

 

[DennisG01]

Check and make sure it is not feeding back through your alternator. Get an amp meter. Remove one of the battery cables. Put amp meter between cable and battery terminal. As you know you have a drain it should be showing a draw. Unplug alternator. If draw is gone you have a bad alternator. The diodes going bad will not always show up on the diagnostic computers. Had a $20,000 Sun machine tell me my alternator was good but the $25 multimeter told the truth.

After unplugging the alt, I would still see the draw from ECM, radio, etc., right? I guess I'm just looking to see if the draw changes after unplugging the alt? In other words, under normal circumstances, an alt shouldn't draw anything?

By the way - I made one of those rushed, stupid mistakes yesterday morning when I hooked up the passenger's side battery and left for work... I have a regular outlet outside and an outdoor timer set up for glow plug use - it's set to go off around 9am. Guess what I plugged the charger into? ut:
So, the passenger's side was then charged last night, the driver's is now charging.

I did try starting it on one battery this morning - it cranked - not as fast as it should (maybe not fully charged). But, I think the driver's side was so dead that it didn't have enough juice to run the electronics or the lift pump. I even put the driver's side on the 55amp "starting" setting for a few minutes. We'll see what happens when I get home.

 

[Turbine Doc]

If going to not charge for extended periods, best thing you can do is to provide trickle charging via electrical powered charger, or solar one on the dash. All batts will self discharge over time, 1st thing I do with new abttery is to put on a charger, as even new on the shelf stored ones are at some state of discharge. How often as well as quality of the charge are important, make sure your self regulating charger is still regulating the charge, it will have same effect of "cooking" or undercharging the battery as a bad alt or gnds/connections will have. Lots of info on web about batts, I had to get up to speed about bats/charging when I went solar power at my hunting camp, here is one of the better battery sites you can start with: http://www.trojanbattery.com/Tech-Support/FAQ/Charging.aspx

 

[schiker]

My truck has sat for 2-3 weeks and cranking speed was close to normal speed cranking as far as I could tell. I think I have let batteries sit out of the truck for a month plus and started on reassembly A OK.
However, if I forget to turn off my Sirius radio (add on plugged in cig lighter) it will kill batteries in 2-3 days easy so dead it won't do much of any cranking. So watch any add ons and how they draw power (direct or relayed through an accessory circuit).

Ramblings....

Where I work the first time we crank up a new machine we test it up then park it running for an hour or so to fully charge up the new battery so it will be "topped" off and ready for a dealer lot. On the dealer lot it might sit a while.

One battery can kill the other as the voltage will "weep" to the weakest "cell" or plate??? So it doesn't take much to draw down then stress just one battery with glow plug and starting too. Which then I have heard repeated hard use of a battery and quick charging (alternator charge) will use up electrolyte out of a battery (evaporate?) due to heat and bubbling action of the chemical reaction even a no maintenace battery. Not sure about sealed batteries like optima's. Any plate of lead that becomes exposed will oxidize and burn out. They make additives that can help clean up and improve the electrolyte lead interface and were good for older batteries with thicker lead pieces. But today's batteries I think are cheaper and optimize the lead content for profit potential etc so once any plate oxidizes might as well replace 'em. The above mentioned alternator quick charge high amp and heat is also a big difference in life vs deep cell use trickle charge.

Clean batteries on a non conductive surface will out last a battery placed on source that will accelerate drain. Have heard never put batteries on cement or the earth ground. Better to put them on wood or plastic etc. Even though the case is non conductive dust, grit, grime, and especially corrosion acid residue on outside of battery will make a slight connection to earth and increase drainage of charge. Not sure if its a wives tale and I have never heard anyone explain it scientifically but many people have said cement will kill them pretty bad. Maybe its natural earth flux or some ionic thing???

Waiting on GMCTD to jump in and learn us up on that sillyness :smile5:

 

[DennisG01]

Have heard never put batteries on cement or the earth ground. Better to put them on wood or plastic etc. Even though the case is non conductive dust, grit, grime, and especially corrosion acid residue on outside of battery will make a slight connection to earth and increase drainage of charge. Not sure if its a wives tale :smile5:

Yes, I've heard that, too. But, then about 2 or 3 months ago I read an article (not sure where I read it, but seemed legit - possible some battery manufacturers website) that debunked this. It said it used to be true when cases where made of a different material that allowed exactly what you said to happen. But with modern plastic cases, it is no longer an issue. It also talked about cold/hot. While cold will keep the battery from giving it's full power, it will not affect the usable life. Excessive heat, though, will shorten it's life. I think we all know about the heat issues, I found the cold statement interesting.

Shiker - I did install a new radio - one of those flip-out touch screens with a back-up camera. Looks like I got a couple of things to do an amp-draw test on.

TD - Totally agree with your statement. In a case like mine, I'll use the regular old Sears Special charger (2/10/55 amp, then switches to trickle) on the 2 amp setting overnight. Then I'll let it cool and use my Battery Tender on it.

 

[packratt]

Probably Interstate's site. They have an article up in my local distributor about the battery sitting on ground.

 

[DennisG01]

UPDATE: Voltage #'s

Haven't done a draw test, yet. But over the weekend I measured the battery voltage at various times. I left the crossover cable disconnected throughout the time period.

1 hour after engine shutdown:
Driver's Batt = 12.83, Passenger's Batt = 12.86

6 hours after shutdown:
Driver's Batt = 12.40, Passenger's Bat = 12.76

26 hours after shutdown:
Driver's Batt = 12.39, Passenge's Batt = 12.68

I'm going to let it sit for 3 or 4 days and do it again. Hopefully I can get to a draw test this weekend.

What's considered normal for voltage loss over time?

 

[Matt Bachand]

Not sure, but its based on a %, meaning the first hour will lose more than the 3rd because its x%/hr. (or day). So.. on that theory the 2nd half of the battery will last a whole lot longer than the top.

If you have a bad battery, you probably wont be in the 12's at all.

 

[SnowDrift]

Batteries sit on store shelves for months and still retain their juice, don't they? I'll hook up an ammeter to check draw, but shouldn't batteries last longer? Would the ECM, radio memory and whatever else that has a constant draw be enough to kill the batteries in a month? They are less than a year old - matched set, 900cca.

The last time I drove my truck was about a month ago. Today (about 40* outside and I plugged the block heater in last night), there was enough juice to unlock the doors, turn on gauges, idiot lights, etc. But wouldn't turn the engine - I got more than a "click", but not enough power to completely start to spin the engine. I didn't have time to do much else, I just hooked up a charger and went to work with the Honda - although I disconnected the crossover cable and for now the charger is only on the passenger's side.


How long have some of you been able to go without having to charge? Or, am I expecting too much?

Mine's got a matched set of Interstate batteries in it from my gasser I had about 6 or 7 years ago and they're still strong today. They sit for a month or two on end in the winter with no charger. Last winter, I had to fire it up after it had sat about 4 weeks on the coldest day of the year in that season and it wasn't plugged in. It was about 10 below outside and probably near zero in the garage where it was sitting. She was noisy, but started right up.

Interstate dealer should charge batteries for you if they have been sitting on the shelf. Warranty starts from when you purchase, not manufacture date.

 

[DennisG01]

Update - amp draw

Ok, the truck has sat for about four or five days, with the crossover cable disconnected.

A simple voltage test showed the Driver's side battery now down to 12.08, the passenger's side at 12.51.

I disconnected the negative cable and put my meter between the cable and negative post. The driver's side initially read .234A, after about 3-4 seconds it dropped to .088A, then after another 3-4 seconds, it settled in at .067A. The passenger's side read 0.000.

What do you think?