2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

The car is an 88 Crx si. Just got it back on the road from a overwinter build.

The car ran mint 2 weeks ago when I took it for a few hour trip out of town, electrical system was fine.

2 days ago I start driving it again and noticed that after a while of the car idling and me turning it off an on (no driving, I was tuning idle and such) that the battery was getting weaker. Eventually the car didnt start

I figured my battery went dead or I got a bad one (battery was BRAND NEW 2 weeks ago). SO I grabbed the dinky small one out of my truck and threw it in and it fired right up. Went for a 30 min drive tonight without turning the car off and came home

Went out 2 hours later and the car wont start, barely has enough power to light up my gauges and start the fan.

So now Im stuck, the battery is brand new, could be bad but I swapped it with a known working one that I drive daily in my truck and it still killed it.

I also read that if you get the car running and then disconnect the negative battery terminal that if the alt is bad the car would die, well the car kept running when I pulled the negative terminal.

The alternator was replaced about 14 months ago, sat through winter, worked just fine a few weeks ago on my trip. but my battery isnt getting charged

The car is obd0 and the motor is a d16a6. I need some help on how to diagnose this ---- please. I need this car

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

1) take off alternator
2) go to autozone
3) have alternator tested.
4) have batteries tested/ charged for free

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal D
 

Thats not true, it depends how bad the alternator is, Also, you may need to check all the wiring again to make sure nothings fried or theres no shorts. Also, make sure you dont have a light or switch on somewhere that you dont know about draining your battery.

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

get a multi meter out, check batt voltage when car is running, if its under 13v alt is bad

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

The alt was a rebuilt unit

Is there a certain time when you have to check the power level?

Like if I fully charge this dead battery like im doing now, throw it in the car and start it up, will the atl still read the higher voltage?

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

just because its a rebuilt alternator doesnt mean its good.. i put a rebuilt alternator into my truck and it was fucked up.. i took it bacck and got another one.. and it worked fine...

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

yea def.ly check the alternator. I replaced the alter. on a corolla with a Kargen rebuilt unit :l and it went bad within a week, luckily it came with life time warrenty

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal D
 

OEM for the win. Stick a stocker new Honda one and let it last another 17 years without touching it :X.

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

I dont believe it is the alternator though because the car will run when you disconnect the battery when you kump start it

Meaning the alt is keeping the motor going

Its new and it worked a week ago and when i searched people said thats how you determine a bad alt

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

ditto, except mine charged just find, it was the regulator that was fubared, 18+v aint good for my car.. mm that smelt good.

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

Wehn i did my swap I had a bad alt...get a multimeter check across the battery terminals with the car off should be 11-13v I believe or around there...then start the car and check again, if its the same then the alter is bad, I think it should be around 14-15v...you wouldn't be the first person to get a bad rebuilt alt, sounds like you problem if the alt is putting out 11-13v its enough to keep the car running but not enough to charge the battery..HTH

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

Well you really have to check and see how many volts your putting out with the car running at the battery. the alternator is probably weak. it's still making enough juice to run the car but not enough to charge the battery.

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

Well I guess im pulling the altnernator if cleaning up the grounds doesnt work

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal D
 

Did you try the multimeter? its really easy and may save yo sometime and trouble

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal D
 

Definately check for something that could be draining the battery. If the car runs fine, and it started fine on a "fresh" battery out of your vehicle, and then you left it with this known good battery for a couple hours and it was dead, doesn't that tell you something is draining the power from the battery?

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

Well I think I found the problem

One battery is garbage, the new one, wont even charge up in my truck

But this small battery is mint, stays 12.6volts and in the truck the alt powers it to 14.5V

So I throw the good battery in the car, connect the ground, connect one end of the multimeter to the positive terminal and one to the positive cable wire (there not connected) and I get a 12.5volt reading on the multimeter

That means something is draining some serious power right?

How do I find the fucker

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

if u have 12.5 ish not running thats perfect, if u have 12.5 while it is running your alt is fucked, ypu should have almost or just over 14v's running

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

I have 15.5-16.5 when running

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

It sounds like its over charging. If its a reman, it should have atleast a 1yr warranty if not a lifetime. Take it off, and get it exchanged. It probably shorted a cell inside the battery from over charging, thats why the new ones junk, if you keep the one out of your truck in there, it too will short a cell.

I heard this somewhere...you can test the battery for shorted cell by switching your volt meter from DC to AC, If it reads anything alternating, its shorted (I think I remeber that correctly).

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

My battery is definetely being drained by something
I cant figure out how muhc is being drawn though, what does the sign look like or say on the multimeter, i dont understand this thing

Thanks guys

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

ur battery is getting over charged if it reads 15.x + volts with engine running.
The regulator which built into the alternator would be the cause, just take it off and have it checked out for FREE at autozone and stop guessing.

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

My battery is being drained when it is sitting as well. I can drive the car for a while and disconnect the battery and when i come out itll start up just fine, shhowing me that the battery is being charged

LEave it connected and the voltage on the battery starts to drop, i cant figure out how to find out how much, I have a 2 prong multimter but on every setting I use I either get an error reading or something complrely different that 50 milli amps. I dont even know what sign to put it on to get a milliamp reading

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

If it has a SHORTED cell it will drain itself over time!!! THINK about it. If you take a AA battery with a piece of wire and a resistor, and connect the 2 ends, it will be similar to a shorted battery seeing as the resitor would be a 'shorted cell' similar as to your car battery. Now, connect a bulb to it also with the resitor connected still in paralell circuit to it, and it will light up ok (bulb is load of engine trying to start). Leave the resitor on, but remove the bulb, wait 1 hr, try the bulb again, doesnt light does it? (like trying to start your car again) It just drained itself from its own shorted cell. Think about it real slow, its not that hard. Get a new battery, replace the alternator, and it will be 100% again. If dont want to take anyones advice, dont ask.

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

dude just for the record u r not sposed to run ur car with either of the battery cables disconnected..ur battery acts like a buffer for any surges of power that ur car shoots out...also if u still want to check if ur alternator is bad then get a multimeter and put it on AC voltage...then while the car is running stick it on the two terminals and if it reads more then .5v in AC then that would mean that your diods in ur alternator are shot and its letting voltage back the other way and causing a draw on ur battery...also try cable to post voltage drops...see if u have any resistance in ur connections