After sitting for around 10 days my Disco ended up with a flat battery 6 volts indicated, the battery is about a month old.

After getting the truck started, I took a short 30 minute drive, the battery showed 12.19 volts this am 11.79

I need to go out this morning so I monitored the charging rate, it bounced between 13.5 and 13.9 with nothing on and everything on.

So no problem I thought 20 minutes later I am bouncing between 12.5 and 13.6 -mostly right around 13.2 as above it stays stable underload.

All voltages measure at the ODB port.

Any suggestions where to start - I am thinking alternator getting hot and under performing but I suppose it could be the battery

 

The charging numbers look normal to me. Mine goes from around 13.8 to 14.5 on my standalone aftermarket gauge. My OBD reader always shows about 1V lower.

The battery numbers look a bit low though. Should be pretty close to 12.6. Draining it to 6V isn't good, but one discharge on a month old battery shouldn't kill it. Do you have a charger that you could run overnight?

 

Red5 I do I have been trying figure out what could have drained it, it has been very warm here and I have never had a drain issue before. But then my Disco does not usually sit for that long either. It could be an iffy battery I have never seen one run that low before

 

Mine kinda started out of the blue as well. I'm thinking alternator or door switch at this point. Got a thread going here on battery draw, but not much input so far...

 

Voltage shouldn't be jumping around so much. I'd check all terminals and cable ends, first. Especially, ground cable at alternator bracket. A poor ground, will result in poor charging system readings. If the problem still happens, yes...check alternator at parts store.



Brian.

 

Back to this stupid battery issue

At that alternator 14.4 volts - positive to alternator casing
At the battery 13.8 at posts
ODB port reports lower - which is fine I can figure that out

Checking warm and everything on voltage shortly

My negative cable to the battery looks iffy damaged in one spot- where does that terminate it should really be replaced.

Battery does not seem to charge - I am thinking it is no good.

 

Still working on this but I discovered a few things :

• My 10 (yes 10) driver side ground all need a cleaning - did that and added some dialetric grease. That along put my charge to a solid 14 volts up from 13.7
• My Negative lead was ok but added some grease to an exposed cable and cleaned up it's ground point
• Discovered the Torque App I use does not report battery voltage correctly hooked up my Foxwell Nt 520 and it does. I will need to add a gauge.

Good news is my alternator puts out a solid 14+ volts
But I still have a slow draw, it appears to be very small