My battery was pretty dead yesterday - still ticked when turning key and the power locks and interior lights still worked - so it wasn't completely gone.

I left on trickle charge last night (2 amp) and it the charger indicates it is almost back to full charge.

Question. Assuming it starts, will the battery be trustable (word?) or should I replace it? It's only 25 months old.

 

Its tough to answer the question about the life of your battery without having it load tested. Some places will do it for free. So, I would suggest getting it done if possible.

You did not mention how long long your car had been sitting. I'm just wondering if you have a severe drain on your battery while sitting. You can do this with a DVM and go between the battery and the battery cable and check the current drain.

I'm no "guru" just trying to help out.

 

I put a new battery in about 2 years ago, the first year it could sit for months and start right up. After that on a full charge it will last a week or two before it goes dead. I guess its time for a battery tender.

 

1)Just running a battery down once shouldn't really hurt it......

2)Sounds like what you did was just let it sit too long without charging it...a drain is normal......depends how fast the battery went dead as to whether it is good or bad.......should be able to start car for at least 4 weeks based on my experience

3)I would get it charged up like you are doing and then watch the battery voltage......if you don't have a voltmeter, just use the digital meter in the instrument cluster..(With the engine off mine tested about 12.5 volts.....one day later it was 11.5 volts.....conclusion probably one bad cell)...

4)So either have it load tested or just watch it a little to determine what is going on......

 

If the battery has a bad cell, a small 2A charger overnight may not bring the battery back to a fully charged condition, but it will be enough to get the car started. Once the car starts look for 14.5-15V on the dash display. If it's less than 14V, either the battery is not taking the charge or the alternator may be going south.

A battery that's only two years old shoud be in decent shape. What brand is it and what is the CCA rating? If it turns out you need a new battery, go with the highest CCA rating you can find in a Group 75 battery. Look for a minimum of 700CCA.

As mentioned, have a battery load test done. This should be done on a fully charged battery so have a shop fully charge the battery with a big charger. Check out the charging system too.

There is a possibility that there is a current draw of some sort caused the batery to die. The underhood lights are a possible culprit and they will draw a battery down overnight to the condition you had. Console box light is another one to look at.

 

While we are here, I have the same problem. I don't usually let any of my cars sit or a period of time. But we stopped racing at the end of November and December is my busiest month at work, so the car sat for four weeks with an occasional start up.
Well the battery died, I threw the charger on, car was fine. 3 days later, dead again, threw it on the charger, car was fine. A week later dead again almost, it barely started, but it did start. Took it for a spin and I get the SYS coming on. Just like last time when the battery that came with the car died.

SO now I buy a Battery Tender and the description says OK to use with all Lead acid and gel batteries. Well I have a gel battery. When I opened it up and read the instructions, it says lead acid only.

So I go back to the site and read the description again and the online instructions and it says OK for gel batteries, so I write a letter to Deltran, they tell me I need to get the Battery Tender Plus for use with gel batteries.

I responded with a link to their own site showing where it says OK with gel battery. I have written twice with no response.

So I talked with a few buddies who say that my alternator doesn't care what battery I have it still keeps a charge on it. So I'm wondering why I can't use th etender that says it's OK when the manufacturer says it isn't(but they did say it was OK elsewhere). I think they were just trying to upsell me.

Anyway back to teh dead battery. I had a Diehard Gold in one of my older cars and it was dead the day I brought it home. I brought it back to Sears about 600 times, each time they refused to exchange it, so I lived with it. I had to jump start the car every day to go to work and to get home. When I got gas, I had to leave it running for fear of nobody able to give me a jump.

I tested the battery and found 4 dead cells. I made a vow to never buy a Diehard again(of course I did anyway). I needed a new battery fro my truck, so I took the crappy dead Gold and traded it in for a brand new silver and have had no problems since.

I'm running a NAPA Exide battery in my '93 and that is the dead one in question today, it's barely two years old, so I may ask the guy who sold it to me to exchange it since $100 for a battery, it should last longer than 2 years. It's not holding the charge.

 

I know checkers and believe auto zone will check it for free for you if you bring it in

 

My charger has an LED indicator and it did get full charge over night. Car started right up. I let it sit a couple hours and put the charger back on - still shows full charge.

To be safe I went to Auto Zone and Advance - not one person in the store had heard of a bettery tender.

The battery I have has a 3 year replacement on it so I have some time to make sure it is right.

 

[QUOTE=Mr Mojo]
Well I have a gel battery.

Curious as to what kind....will it work as "daily" driver.??

So I talked with a few buddies who say that my alternator doesn't care what battery.

I am not sure this is true....I had battery "expert" tell me this was one of the problems with the AGM batteries, like the Z06 had..

I made a vow to never buy a Diehard again(of course I did anyway)..

I made the same vow....about 1969....I have stuck to it!!!

 

Mojo,
I think there is difference on battery "float" voltage between the Gel and lead acid. I think the float after the 14.5 full charge on gel is 12.5 and lead acid is 13.8. Thus, the two types of chargers. The company should answer this for you.

 

From Deltrans website

 

Lead acid batteries self discharge about 1% each day and more if there is some leakage current. When lead acid batteries discharge the plates get coated with lead sulphate which is an insulator and fully sulphated the battery will not draw current from a battery charger and you have a doorstop. Every time you fully discharge a battery it loses some of its amp-hour capacity so if your car is going to sit for 4+ weeks you should periodically charge the battery. A battery tender is the best solution, but if you already have a battery charger, buy an interval timer (turns your lights on each night when you aren't home) and have it charge your battery each day for its minimum interval (usually 15 mins). A load test does not test the battery for reserve time (how long the battery can deliver 20 amps without falling below 12.0 volts, usually about 100 minutes). Sulphated batteries that are charged back up have a reduced reserve time and is why a recharged battery goes dead sooner than it did when new. Lead particles fall off the plates and collect on the bottom of the battery and when high enough, touch the plate bottoms and make current flow all the time which signals the end of the batteries life. The guaranty period of the battery is directly proportional to the amount of space between the plates and the bottom of the battery case. Batteries with debris touching the plates can be charged up but self discharge quickly and these batteries should be replaced.
Gel batteries can be safely charged and maintained with a battery tender, but be certain that the charger doesn't charge at a maximum rate (usually 10 amps) higher than the battery specifications.

In short, car batteries don't like sitting idle for long (4+ wks) periods of time, so charge them periodically!

 

Lead/acid batteries HATE being (deep) cycled. Depending on the battery age, once is enough. Twice is cause for worry and after a 3rd time... My starter-alternator shop explained to me that the batteries that CAN have water added tolerate cycling better than the true, maintenance free batteries. If I don't drive my car for about a month or so, I run an extension cord to the car and leave it on a 2 amp charge for about 24 hours. Corvettes built after '85 or '86 don't have the alternator to recharge a dead battery. It may do it once or twice, but it takes it's toll on the alternator. The battery should be recharged, rather than jump started and allowed to recharge off of the alternator.

From posts on this forum, I don't think there is any advantage to the gel-cell batteries.

RACE ON!!!

 

LT-4 CE,
I think that everyone agrees that one of two things are happening. Either you have excessive current draw while your car is sitting or a bad cell in the battery.
Mojo,
I'll check out the website, I just wanted to share a little info with you. People have different thoughts on how batteries should be maintained.

 

I had an alternator rebuilt by an old school shop, and he said the most common cause of alt failure was due to the battery (age, number of times completely dead ...) He also recommended a new batt should accompany any/all rebuilt or new alternator. What would constitute a "new" battery? I guess if it were no more than a year old.

I can't tell you how many maintenance free batteries I have had a green eye that wouldn't do squat let alone pass a load test.

 

The car sat in an un-insultated garage from mid-December until this weekend (almost 8 weeks). And it is holding a charge per the charger I have. This is a new house and is scheduled to be insulated. I didn;t have a problem last winer in my old house.

 

That's not too bad. I guess I will be a battery victim as well, my car has been sitting outside for about a month now. I figure I should be good for about 8 to 12 weeks based on drain, temp.

 

I know about the modern alternator not being able to keep up with charging a battery as well as taking care of the rest of it's duties.

Is there even a non maintainence free battery anymore? I haven't shopped for a battery in a few years but last time out I recall almost all being maintainence free.

I bought the Gel Cell based on the understanding that it would take a charge better than the old lead acid type.

Form what I've been told the lead acid can only take a drain so many times before it will crap out for good(which was the case for every battery I've had before 1997).

Other than the Diehard Gold I mentioned above, I've always had good luck with batteries, but with racing seson at a pause and me being lazy and not wanting to put street tires back on, I parked it in the garage expecting to drive it a little more than I actually did.

I didn't expect the battery to crap out after 3-4 weeks, but I did expect it to hold a charge.

I bought the Battery Tender because of all the good things I've heard and my current charger is about 35 years old. SO it was time for soething else. I'm still planning on buying a new charger for use in the garage.

I just wish I would get a reply from Deltran explaining why they say two different things.

 

In my experience, Exide batteries only last about 2 years. So your battery fell right in line with what I would expect. Personally, I stay away from Exide. I don't know many people who have been happy with it. They normally said they lasted a relatively short time and had to be replaced. Spending that much money on a battery ($100), I would think you had to have received a pretty good warranty (2-3 year full replacement or 7-8 year pro-rated). Or at least I hope you did.

 

Well, I forget exactly what the warranty is, I believe it was full replacement for two years and 6 years pro rated. I do know the owner of the store who sold it to me, so I shouldn't have a problem replacing it for free or very cheap. Now if he would just answer the phone.