Noob at Electrial Issues - Where to Start - Battery
 

Alrighty gang.
Battery is a AGM that's about 2 1/2 years old. Odyssey.

Just started yesterday. No Crank. Hooked it up to the trickle charger at 8 ah for 10 minutes, enough so that it would crank and off we went. Drove, couple of stops, came back home, left it running for another 30 minutes before we shut off.

Today, same deal. No crank. I've got the charger on it now. Might trickle charge it till it goes into float mode.

I'll start the car and put a volt meter on it to see what it reads. Had wife check the cluster all day and nothing weird on the cluster (aka, alternator light or battery light error). Assuming it reads less than 13.5 , then I can assume it's the alt....

1st thing 1st. Is the best way to isolate if it's the battery 1st is to take it out of the car, charge it, remove terminals and see what the charge is on it overnight.

I suppose possibly this weird ballast issue could be the root cause of it....I'm in the middle of knee deep deadlines + a disaster recovery issue I was working on earlier so literally, I don't have time to play weekend warrior mechanic.

Thoughts ? Suggestions
http://www.xoutpost.com/bmw-sav-foru...ing-south.html

Charge battery until it floats on the charger your using. Use a volt meter to read static voltage
Results over 13v?
Less than 12.5?
Who the hell knows? (Too low and falling?)

If the 1st one install battery and finish work. The vehicle will run on the battery only if the charging system is out to lunch.
When you time there is a complete electrical test approach that will uncover the issues:
Battery not likely based on your postings
Charging system
Wiring issues/ system draw when off

quick test After the battery is fully charged.
Car off battery tested at terminals
Voltage?
Start car
Test same way and read voltage
Increase in readings?

Post the answers

Helpfull?

Quick update..

Same deal. Ran a charge at 8ah for abt 10 minutes, started car.
Put meter on it and it was reading 14V

Turned off the car and I think it was at 10 or 11....can't recall.
I took out both headlights to replace the ballast
While it was out, I put the fresh 85122+ bulbs in them. More work on headlights needed but that is a different diatribe

It's slowly been charging. I went with my tried and true low and slow 2 AH. It was taking forever so I went to 4AH. It's now at 12V. Negligable speed in charge so I'm now charging at 8AH and will check back again in a hr to see it it's closer to 14V ....and getting ready to float.


I suppose the next test is to let it charge to float, and then see what the volt is from a charged state while someone starts the car ?

I've had really bad luck with AGM batteries.

I own a performance company, and have a lot of customers who want smaller, AGM units due to either weight reasons or physical six constraints. There are always a few people that have had years of use out AGM batteries without issue, however most people will see a few instances of deep discharge because it wasn't unhooked while storing the car, or ran dead by some system being left on (lights/stereo/whatever).

After that point, we can often get them to take a change if you let them slow charge overnight, but even with the battery sitting on a bench they will typically float back down to sub-par levels, or their reserve capacity is severely diminished.

The only good thing I've experienced is that most battery wholesalers don't even question a warranty claim on them and just trade them out no questions asked.

Great battery if you keep them charged constantly, but quickly develop issues when not kept in this manner.

charge.. .+drive... + no drive.. over night disconnect the battery. reconnect before starting.. dont know where im going or what to do next.. drop off at mechanics... if monkey mechanics - print out my instructions...

It's the battery.....it went into trickle mode around 10PM in the evening. Since then, it's been went float with with the indicator that the battery was too sulphated. Have had it on maintence mode since then, and 7-8 hrs later, it's reading at less than 13 volts

Hi.Try to charge that battery up and if it dies again ,read the error codes and then you will know the issue,I guess.

put your headlights on and see what your battery voltage is ,x not running. you will see if the battery is strong or not by watching the voltage decline. if it declines rapidly then you know its your battery not holding charge.

Battery Tender was reading too sulphated....so I'm swapping under warranty..regardless

Threw the jump pack in the car and we took the X out today.... Had the X parked for a solid 12-13 hrs and came back to it and it started just fine !

I dunno. I suspect it was either a combo of the funky ballast doing weird things that might have popped the trunk and drained the battery. In addition, picked up the car about 3-5 weeks ago from the bodyshop and I'm fairly certain, the battery went flat, as when I picked it up , all the presets were gone. I suspect since the time of the bodyshop, the battery may not have been ~topping off~ since then.