The old main battery is now gone, tested bad after an overnight charge, couldn't take the load. It was ok for the most part but failed load testing, it was also the original battery from 2005.

I will agree the charger is rather small, I can charge up the auxiliary battery but that takes the full 10-12 hours to charge that small battery, I am imagining that the main will take a couple of days on that charger.
I will do some more reading and update this thread, if nothing else, this wil help someone else in my shoes.
New alternator (Bosch) ordered. Am I being cheap buying a new unit online for 300 vs OEM for 700? I hope this doesn't bite me in the behind like the first so called bosch reman did

 

More news, the Alternator is toast, just did some testing and under load the Alternator cuts out. Battery tested at 13.3volts on the main one. Aux tested in the very high 12s. Even with load they held up fine, Alternator on the other hand didn't fare so well

 

OK POS Alternator, So orginal died, you replaced it with reman Bosch it dies, after replacing the voltage regulator and two shops that tested it and told you it was good.
I would still get an amp gage on the output of that new alternator just to confirm your dose not have any extradnornary high amperage load on it, you see, in this case the high load was most likley your OEM battery.
It might be good to monitor your voltage for the next few days too.
FWIW this makea a case to buy new parts.

 

Actually I do not think the alternator died, I believe it was dead on arrival. The car left me on the side of the road the first day I tried taking it to work after the alternator was put in. That's how battery replacements and VR replacement got into the mix to begin with

I just don't know how it passed bench tests though

 

Glad it worked out for you, did the auto place take back the alt and give you a credit for the core you gave them. It took a while to figure your problem out, but given the results it is well worth the aggravation. Getting that service life out of a battery is over the top but normally I change out batteries at 5 or 6 years, easier on the charging system and possible contribution to your burning alt issue trying to charge a shorted out battery ( sediment falls to the bottom of the cells and causes them to short out which increases the resistance of the battery) Resistance is heat for the alt.
Happy Motoring now.

 

That is why AMG batteries are best.

 

Thank guys for all the help!!!
I will be back here *****ing if after install of new alternator I have any charging issues! lol

N_Jay, AMG battery is DEAD, aftermarket one lives on

 

Sorry, typo, AGM

 

Oh Ok, well my aftermarket one is full AGM also :-)

 

Surprised your factory one was not.


My '07 (Delivered 12-06) W211 (non-AMG) original AGM battery is going fine at over 7 years.

 

NJay you should ask for a DYI on alternator replacement, that 7 year old battery will bite you in the *** soon enough. Just when you need it most, besides an old battery is hard on the starter, voltage is the carrier, current does the work. Thats why some batteries will show good voltage but fail on the load test.

 

Don't worry.


I know the signs of a bad battery.


I just had it load tested.


(Of course all this mentioning of it will likely cause it to fail out of spite!)

 

Ha ha so true, really just how much longer do you think it will last. Leave the lights and heater on for about 20 minutes and then try to start a cold engine, maybe it will maybe it won't. I like to replace at my convenience not in some parking lot miles from home, because that is where it will fail. You must live in a moderate 70 degree climate or garage your car nightly. Maybe? Ask Kponti about old batteries.

 

Live in the cold (gives longer battery life) and also garage the car most of the time.

 

Battery failure will occur on the hottest day or the coldest depending on location and urgency of need for the car

 

Shhhhhhhhhhhhhh!!!!!!!!!!!!!!!




Don't give it any ideas.