DEAD battery with a battery tender on it

[stal023]

So what are my possible issues if my car is still completely and utterly dead after not driving it for just 3 days and I have a battery tender on it? Alternator, what else could be the issue?

 

[Smartbear]

The battery could just be beyond help, tenders can’t perform miracles if the battery is just worn out.
Rob

 

[pvr]

Perhaps the tinder did not find a match?

 

[Zulu4]

Perhaps the tinder did not find a match?

:rofl:

 

[colb]

Try jump starting it with jumper cables from another vehicle or known good battery, if the starter motor turns and the car starts then you will know the starter is ok. Once running disconnect the jump leads and then using a voltmeter put the leads on the battery terminals and see what voltage the alternator is putting into the battery, you should see at least 13 to 14 volts. if you get that then the fault will be the battery has died and not taking the charge.

 

[stal023]

I had taken the battery in to get tested and they said it was fine. I will hook up a multimeter to the battery and alternator tomorrow. I saw this youtube video to test the alternator - https://www.youtube.com/watch?v=C2sU0jdop6o

 

[warmasice]

Just make sure the wires that connect to each clamp are secure. Sometimes one of the nuts works loose.

 

[colb]

That video shows how to test the diodes in the back of the alternator, just testing the battery with a voltmeter and engine running will display what voltage the alternator is putting into the battery or isn't if the alternator has a fault. If its not putting voltage into the battery of at least 13 - 14 volts it will be an internal alternator fault. The video test can be then done to see if its the diodes in the regulator within the unit that have failed. You can buy replacement regulator packs to repair if the rest of the alternator is still good. If high mileage I would put in a recon unit to be sure of a lasting repair.

 

[Wildfire]

What colb said.

Check you battery is charging by putting a multi-meter across the battery when the car is running. Then work back from there.

 

[stal023]

Battery and alternator seem to be fine. Seems like something has to be drawing it down faster than the tender can keep up with. What size tender do y'all use?

I have the top end sound on this car, does that amp stay on full time?

 

[colb]

If you suspect something is drawing current whilst the car is switched off, known as a parasitic drain on the battery you should do a voltage drop test with a meter on the battery to see whats being drawn. Probably best to watch a Youtube video on how to find a parasitic leak, it will involve using a volt meter on the battery and removing individual circuit fuses until you find which circuit and what is running off that circuit is the cause. Could well be an aftermarket Amp if it was recently fitted and is now causing the battery to run down.

 

[jamesditchy]

My money be on the battery. Just had the same issue with mine. Changed battery and you can tell the difference massively on start up. Was on a run with a forum member, battery on trickle charge for days. Started and drive 70ish miles. Stopped for a chat and totally dead. Wouldn't start with push or jump leads. Tool battery from other car and started 1st time. Changed battery and no problems since