Car needed a jump

[BrianMarks]

I was at a stereo shop going over options for more upgrades to the audio system on my car. I had the stereo on for about 15 min without the car running. When I went to leave, I heard the dreaded "clicking" and windows went down. The stereo guy gave me a jump, and I drove it over to a European garage. He put a doohicky on the battery and said that the battery looked good, but that its only throwing 13.8v and it should be around 14.5, and you need a new alternator. After doing exhaustive searches, 13.8 doesnt seem low. it was at dead idle when he measured it. She is sitting at home right now on the trickle, I will see how that works.

Also, the car started at the mechanics place when I left, so it is charging.

Is 13.8v low? there are no error codes, all looks good.

this is a 2000 C2 cab manual

thanks

b

Edited September 21, 2011 by BrianMarks

[logray]

13.8v should be good, but a real test on an alternator is current draw (amps). not voltage.

It could be the regulator on the alternator.

But I would just charge the battery, and take it for a couple long drives. It should be OK.

If it happens again I would suspect battery, alternator and/or voltage regulator, or corroded wires.

[BrianMarks]

13.8v should be good, but a real test on an alternator is current draw (amps). not voltage.

It could be the regulator on the alternator.

But I would just charge the battery, and take it for a couple long drives. It should be OK.

If it happens again I would suspect battery, alternator and/or voltage regulator, or corroded wires.

thanks! Would low Amps throw a code?

[judgejon]

I think low amps would show up with psm and abs lights coming on. Alt symptoms are weird, but if you do need one replace batt at same time.

[JFP in PA]

Low voltage may or may not throw a code. Sometimes a dying alternator will trigger ABS and PSM MIL’s, but not always. I am also not comfortable with any voltage readings below 14V at idle.

I’d suggest load testing both the battery and alternator; the sequence only last a couple of min., but will confirm the viability of both units.

[fpb111]

After charging the battery or jump starting the car, connect the voltmeter to the battery the same as before and note the charging voltage. A charging system that is operating normally should produce about 13.5 to 14.5 or more volts at idle. If the charging voltage is less than 13.5 volts, the alternator is not putting out enough current to keep the battery charged. You should have the alternator tested (or bench tested at an auto parts store). If the current output is not up to specifications, replace the alternator.

The standard automotive battery in today's vehicles is 12 volts. Each battery has six cells with 2.1 volts. A car battery is considered fully charged at 12.6 volts.

When a battery drops voltage, even a small amount, it makes a big difference. For instance, when a battery drops from 12.6 to 12.0 volts, its power drops from 100% to 25%. At 12.4 volts, a car battery is 75% charged. At 12.2 volts, it's 50% charged.*

Edited September 23, 2011 by fpb111

[BrianMarks]

After charging the battery or jump starting the car, connect the voltmeter to the battery the same as before and note the charging voltage. A charging system that is operating normally should produce about 13.5 to 14.5 or more volts at idle. If the charging voltage is less than 13.5 volts, the alternator is not putting out enough current to keep the battery charged. You should have the alternator tested (or bench tested at an auto parts store). If the current output is not up to specifications, replace the alternator.

Appreciated the info. The mechanic told me that it was putting out 13.8 Volts. that is what threw me, that seem sufficient to keep the battery charged, yet it didnt. I left it in the garage with the trickle charge for the past two days, and it started right up this morning. Will see if the charge holds.

By the way, the volt meter in the car is reading 14V dead on.

[jimmy3530]

Hi everyone

Lately my 2000 C4 has what seems to me, trouble starting. It just seems like the engine coughs to life after you stick the key in and turn it. It's not trouble starting like you need to crank it for a few seconds. It just seems to be that it should come to life faster and with more conviction.

I'm thinking I need to replace the plugs and will do that soon. It has 58,000 miles and so they are due for a change. After reading a bit here, I'm starting to think that maybe I need a new battery. It's probably 5 years old by now (its aftermarket). I see a post up above that the battery gauge in the car should read about 14 at idle. I'm at 12 - 12.5 at best. On starting, it drops to 10V or so.

So, I have 2 questions:

1. What is the preferred battery for this car. I'd rather not get a Porsche $$$ replacement battery

2. Do I need to take it to a shop for the load testing. Can't I just buy an ammeter and do it at home?

Thanks

[scottiemac]

Hi everyone

Lately my 2000 C4 has what seems to me, trouble starting. It just seems like the engine coughs to life after you stick the key in and turn it. It's not trouble starting like you need to crank it for a few seconds. It just seems to be that it should come to life faster and with more conviction.

I'm thinking I need to replace the plugs and will do that soon. It has 58,000 miles and so they are due for a change. After reading a bit here, I'm starting to think that maybe I need a new battery. It's probably 5 years old by now (its aftermarket). I see a post up above that the battery gauge in the car should read about 14 at idle. I'm at 12 - 12.5 at best. On starting, it drops to 10V or so.

So, I have 2 questions:

1. What is the preferred battery for this car. I'd rather not get a Porsche $$$ replacement battery

2. Do I need to take it to a shop for the load testing. Can't I just buy an ammeter and do it at home?

Thanks

To answer your second question, you need a special tool to do load testing on a battery. They disconnect the battery from the car loads, hook it up to the load tester and watch how it reacts to a high load. It doesn't take very long - a couple of minutes.

To your first question, your existing battery will likely have some markings on it indicating the group number (I think it is Group 48). I have a no name battery (literally no markings except somebody wrote a number on the side with a crayon) in my car that I've had now for 4 years. I keep it on a tender and monitor the levels in the cells and it has been OK so far. When I replace it I intend to get the biggest recessed post battery with the highest cold cranking amps that will fit in the tray. If you look at the battery tray in the car there are two mounting points and I want to get a battery that is longer than the OE one and fits in the larger of the two mounting points. Hope this helps.

Cheers

[logray]

A good battery thread, I like the costco one myself

[fpb111]

Another good battery thread

http://forums.rennlist.com/rennforums/996-forum/618336-had-to-upgrade-my-battery-after-2-5-years-on-group-48-replacement-battery.html

I replaced an Interstate MTP-H7 With a Braille 7548 AGM battery direct replacement.

Braille AGM B7548 battery group 48

BCI Group: [?]Group 48

Length:10.9" (277mm)

Width:6.8" (173mm)

Height (without posts):7.5" (191mm)

http://www.braillebattery.com/index....tteries/b7548#

Interstate sizes that fit 2003 996

Group

Size Interstate Type CCA1 CA/

MCA2 RC3

(Min.) Warranty

(Months) Dimensions (inches)

L x W x H Posts

H6 (48) MTP-H6 640 800 121 85 10-15/16 x 6-7/8 x 7-1/5 Top

H7 (94R) MTP-H7 640 800 135 85 12-3/8 x 6-7/8 x 7-1/5 Top

H8 (49) MTP-H8 720 900 176 85 13-15/16 x 6-7/8 x 7-1/5 Top

[jimmy3530]

Thanks for all of the useful information here. I did a quick of my battery and it shows 12.3 volts when the car is not on. With the car on, its only 13.1 volts. I think i'll replace the battery first and then look into the regulator.

One more thing, i don't see any batteries for sale at Costco, at least not in Maryland.

Thanks

[whall]

I had a similiar problem with an alternator/voltage regulator a few months ago.

The problem was in the voltage regulator. When the engine, alternator, voltage regulator were cool, the indicated voltage was 13.+. After the car heated up the indicated voltage started dropping - at one point below 11 volts. I refused the dealer's offer to replace the entire alternator (~$1,200!) and took the unit to an independent automotive electronics shop and had the voltage regulator replaced ($82.50). The voltage regulator itself only cost about $25. And it is easy to change. But, I paid a professional do it and test the alternator following the work. The extra money was, in my opinion, well spent to insure I got a reliable electric source.

Now, I have an electrical system that runs at 14.1 volts (after starting) and about 13.5 volts (after the battery has been charged).

Bill

[skyline]

They do not sell batteries any more at costco in the UK. They stopped stocking them a while back.

[jimmy3530]

Will be swapping out my battery for a new size 48 (probably a DieHard from Sears or a Bosch from PepBoys - apparently they are all the same) and I just wanted to know if I should be concerned with electrical problems (i.e., alarm not working, etc.) once the new battery is in. I don't care if I loose my radio presets but I'd hate to screwup anything else.

Thanks again everyone.

[1schoir]

Jimmy:

The batteries are all the same, but the Bosch battery comes with a 3 year full replacement warranty and a further 3 year pro-rated warranty.

If you go to Pep Boys, you can pick up a small device that plugs into your cigarette lighter that can avoid having to reset anything.

You won't have to have your radio code re-entered, and will also avoid possibly having to re-set the windows. Your car won't have to re-learn the fuel trims, etc...

Regards, Maurice.

[jimmy3530]

Hi Maurice:

Just to be clear, I need that device to prevent resetting the radio code, windows, etc.

I was going to hook up my trickle charger to the lighter socket but I don't know if the center is + or -

Maybe buying the 9v battery device is easier.