Bad charge on battery or bad alternator?
 

Got a new battery last year and went to start my car the other day. It hesitated quite a bit (you can tell the charge is low because the console lights dim and the starter turns slowly).

I actually ran out of juice twice in 2 days and had to get the car bump started. Ever since 4-5 days ago (other than the 2 bump starts) I have had slow, sluggish start ups.

Wondering how to tell if its the battery or the alternator. The only thing I have done recently is installed sidemarkers but that was over 2-3 weeks ago and I doubt I have a bad ground.

Another thing. If I turn my car off (after driving for 20-30 mins) and then turn it on 10 seconds after, it starts up fine. Which is leading me to believe that the alternator is doing its job, and I either have a bad battery or a leeching ground. How can I test for which one it is, if am I correct about the alternator.

Thanks!

Re: Bad charge on battery or bad alternator?
 

Get a multi meter and measure resistance.

Re: Bad charge on battery or bad alternator?
 

Sounds like you have either a bad batt., [will not hold a charge] or you have a "parasitic draw", [something is staying on].

You can do a simple basic test for parasitic draw with a 12V test light... https://honda-tech.com/forums/showth...&highlight=fcm 94

Re: Bad charge on battery or bad alternator?
 

Thanks FCM, exactly what I was looking for.

Re: Bad charge on battery or bad alternator?
 

What am I looking for? Values when the car is off or on? What do they tell me?

Thanks

Re: Bad charge on battery or bad alternator?
 

A bad battery can read well over 12v with no load but the load of headlights will drop it very quickly. Use a good car/battery and compare.

Re: Bad charge on battery or bad alternator?
 

How do I know if its time for a new one? Im sure the charge right after I shut my car off is +12v, since I can start it up right after I shut it off...

If I shut it off and leave it overnight, its -12 V...

Leech or bad charge? Need tips.

Re: Bad charge on battery or bad alternator?
 

You can take the battery to an autozone or whatever to have them try to charge it. They can determine for you if the battery is at the end of its life. Think they should be able to tell within a half hour.

Re: Bad charge on battery or bad alternator?
 

It is possible to make a visual check of the alternator. It's easier at night or in a garage.

1 Get the engine running.

2 Have someone increase the idle to about 2000 rpm, and then have them turn on the highbeam headlights.

3 While this is being done, you watch the alternator, for sparks. Sparking windings, in an alternator, will burn themselves completely open, so you need to replace it.

Re: Bad charge on battery or bad alternator?
 

You can check the alternator with a multimeter by revving the car to 2000 or so and taking the reading. A good alternator should read around 14 volts.

Re: Bad charge on battery or bad alternator?
 

had a similar issue battery and alt tested good with multimeter, it was the starter, had weaker and weaker starts until it wouldn't turn over the motor over i thought it was the battery going out, 5 years old and summer time, push starts car runs normal. if you are getting 12v at the battery in the morning, 13 or so when running, 12 at the starter, then I would have the starter tested

gl

Re: Bad charge on battery or bad alternator?
 

DId some tests.

12.6 after I turn it off. 12.5 with key in ignition and BARELY starts. Very sluggish.

Drove for about an hour today, went to the gas station, left my headlights on, got back in the car, battery was dead. Instrument gauge was dim. Had to push start.

Had car at idle, tested with multimeter, 14.4 Volts, very healthy alternator I believe. I am ruling out leeching since leaving my headlights on after a 1hour drive (charge @ 14.4 volts) for 2 - 4 mins drained my entire battery.... yeah thats a shitty battery.

I forgot to mention, bought the battery 19 months ago, warranty is for 18 months (SOL I guess), and for 4 months this summer the car was driven for maybe 3-7 days, I had something else insured. Heard that lead acid batteries need to be constantly charged or they just corrode and die.

Finally, I put my multimeter on my battery and turned my alarm on/off, it fluctuated from 12.2-12.6 but never going above 12.6. I unplugged MANY fuses and the voltage never went up above 12.6, suggesting that there is no power draw from anything else.

Anyone with me? New Battery Time...

Re: Bad charge on battery or bad alternator?
 

See if u can track down a battery charger with a desulfator function. I got one and its improved battery life for all my batteries.

Re: Bad charge on battery or bad alternator?
 

Did you do a parasitic draw test? 94

Re: Bad charge on battery or bad alternator?
 

Most parts stores will load check your battery for free.

Re: Bad charge on battery or bad alternator?
 

Likely your battery will need to be replaced. It may have suffered sulfonation when sitting for a long period uncharged. Even if you can revive it I doubt that it will be reliable for winter. You can get a load test as noted and be prepared to replace it at the same stop and save a trip/

Re: Bad charge on battery or bad alternator?
 

myteggy: Wow, never heard of that. I will definitely do that,

fcm: not by using your method, but yes, I checked for it, and there appears to be none.

dogginator: the place I am returning it to will need to check it before they give me a new one, thanks for the tip

drive_4_fun: good point about winter. Ill probably just go and replace it.

Re: Bad charge on battery or bad alternator?
 

Prob has a surface charge the starter will pull alot of amps when trying to start the car.