Fishy battery issues.... - PeachParts Mercedes-Benz Forum

pawoSD · #1 03-13-2007, 06:19 PM

I took my old DieHard International 100Amp 805CCA battery (which left me stranded) to sears today to get it tested/refunded/changed out...whatever they'd do....so he takes it, brings it back and says it is charged and passed the tests fine. I think this is a load of ####....as the thing left me stranded in KY Saturday with barely enough juice in it to make a light bulb glow.

MB tech installed a new battery in my car (thank heavens for the roadside assistance) at the cost of $142....started up the car, low and behold its showing 14 volts like it should, drove around for a while, stayed at 14v even with the headlights, radio, and blower all on, just above 13V at idle with all that stuff on. Days later here I am, it still goes to 14V when running....and has held the charge fine. I say the DieHard battery crapped out, what do you all think?

Also, back in February I had a day where it was -10 outside and I glowed for about 25 seconds, then cranked for about 9-10 seconds, at which point the battery was dead, no go. So I tried jumping it with another car for 20 mins of charging then attempted to start....no go...so I went and bought a mega charger/starter....charged it for 20 mins at 15A, then flipped it to 100A start mode, cranked the car right up and all was fine...until this incident that took place Saturday....went from 14V to 12V while driving....randomly for 5 mins during the trip it went back to 14V, then fell to 12 again and never went back up. Any ideas on what might have caused it? I still say the battery is bad....10 seconds of cranking is wimpy, when the battery was new I could crank for 25+ seconds without even wearing it down.

DeliveryValve · #2 03-13-2007, 07:20 PM

Take it to another place for another opinion... Like Autozone. I think they do it for free. If they find it is bad, make a complaint to Sears. Seems to me the battery is junk.

bgkast · #3 03-13-2007, 07:34 PM

Sounds like sears standing behind their product.

I'm leery of them after the other scam they pulled a few years back.

pawoSD · #4 03-13-2007, 08:18 PM

Well, I went back to sears....on the way I noticed that my Voltmeter was reading lower again in my car, at idle with the headlights and brake lights on, I was down to about 12.8 volts....it used to be about 13.5 in that situation....so I am guessing my alternator is dying. Idling with no load except the radio it only reaches about 13.6...used to be 14.1.....raising the rpms about 300-400 brings it to 13.9....but it won't go over 14 anymore....even way revved up. I think I may just replace the alternator....it has the ancient style voltage regulator...and those are $55 by themselves....so why bother....its at least 60-70k miles old...and its a re manufactured one a previous owner put on it.

I am wondering if I could use a 70 or 80 amp alternator meant for the 380SE/SEL on the 617? It looks physically identical....connectors...mounting and all....don't see why it wouldn't work, and it'd give some extra output. Anyone else done this? I know I could just get the 65A one for the diesels....but if the 70 or 80 would work, and is the same price...why not.

I want to deal with it soon, so I don't kill my new MB battery too.

I have the old diehard out on the charger, we'll see if it goes back up to a "full charge" 12.6 volts....

Matt L · #5 03-13-2007, 08:51 PM

Ensure that your belt is in good shape and properly adjusted.

pawoSD · #6 03-13-2007, 09:41 PM

Quote:

Originally Posted by Matt L

Ensure that your belt is in good shape and properly adjusted.

Hmmm.....I think it is....it never squeaks or anything...our '83's belts squeaked when they were loose and it had an electrical load....

I may check/change the belts just to be sure before I blow $200 on an alternator....

I have some new belts, I'll try to install them sometime in the next few days.

Hatterasguy · #7 03-13-2007, 10:06 PM

Its starting to sound like the alternator, is their are local place that can rebuild them? Usualy they can rebuild these for $100 and its probably better then an India Bosch rebuild.

mobetta · #8 03-13-2007, 10:31 PM

I'd go w/ the biggest alt you can fit, since your shopping for one anyways.

IMO,the 'puterized battery testers that most shops use nowadays are junk. they dont put a real, full load on. you need one of those old skool units with the big fan and knob you crank down to put on a load. also, have them charge it and let it sit a day off the charger. then test it. bet it fails.

pawoSD · #9 03-14-2007, 01:32 AM

Quote:

Originally Posted by Hatterasguy

Its starting to sound like the alternator, is their are local place that can rebuild them? Usualy they can rebuild these for $100 and its probably better then an India Bosch rebuild.

There is a shop here that does them.....maybe I could get it rebuilt with higher capacity? That'd be cool...

JimmyL · #10 03-14-2007, 01:36 AM

It has been sounding like your alternator since the posts from the trip you took. Why are you not doing the regulator?

deerefanatic · #11 03-15-2007, 07:20 PM

Hey Pawo, I put a 115 amp AL129x alt in my SD and it only cost me $100..... no shipping charge, no core charge...I've been fairly happy with it, and it uses the new-style internal regulator... I've had some similar voltage creepy things going on too.... I put an onboard 1.5 amp charger on the car and let it sit overnight 3 or 4 times. Now my voltage is much better. You get a Hi-Capacity battery like our cars use (Group 49's) and they take a LONG time to come to full charge..... Gotta trickle charge em for years it seems!

But, if you're interested, I can give you the phone number to the place I got my alt from.... They have a 1 year, Unlimited Mileage warranty to. Very nice, clean rebuilt unit....... With new regulator.

Oh, and it's bolt on! (Tight fit, but does fit without mods....)

Give me a call if you're interested, 269-303-1637...... I don't live to horridly far from you, you could see my system if you'd like.......