Battery Time - PeachParts Mercedes-Benz Forum

vwnate1 · #1 02-27-2022, 07:59 PM

Dang ~ my Coupe and Wagon both needs new batteries, the last one I put into the '84 Coupe was an AGM that co$t me an arm and a leg, it's only 3 years old and is stone dead, won't take any charge at all

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The one in the '84 graymarket wagon is *just* over 4 years old, flooded acid .

So, this time I'm buying somewhat by price : 900 A. 1000CCA , not the top priced ones .

I've tried pretty much all different brands over the years, this time I went with O'Reillys , I hope they'll last a while, $480 GASP

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JHZR2 · #2 02-27-2022, 08:10 PM

$480???

I would buy the East penn group 49 from Napa on discount, or else the Walmart version.

These alternators can’t charge batteries well. Undercharging sulfates the plates which is death for the battery.

Very little reason to use an AGM.

Run a battery smart charger. The MB flooded battery in my 240D must be 15 years old now and still works great.

vwnate1 · #3 02-27-2022, 09:16 PM

Thanx ! .

I did try the Wallymart battery once and it was okay, I looked and they're only rated 880 CCA......

If you use the 1985 alternator and the correct voltage regulator they'll charge just fine, I see 13 ~ 14 VDC on a regular basis .

barry12345 · #4 02-27-2022, 10:05 PM

Interstate so called rebuilts. They have been doing okay except one and it may have been my fault. Last type 49 was 59.00. Smaller battery capacities 49.00 Canadian and a dud turned in. Interstate is a bigger name battery in America.

May be cheaper there as the American dollar is worth more. So there should be a factory distrbutor in your area. You do not just want a store that buys them from interstate but a factory outlet store.

Lately being last fall. They have been giving me new second or better as they where out of their so called rebuilts. Of the types I wanted.

They load test fine and have a warranty. Only six months, Usually that is enough time to tell if they are going to go a reasonable distance in time. A lot of the guys around here are starting to use them after I mention it. Best of all the people working there are really nice with customer service and a great attitude.

vwnate1 · #5 02-27-2022, 11:21 PM

Thank you Sir .

As it turned out the O'Reilly ones co$t $190 each plus core charges , taxes and some California 'special fee'........

They sent me an E-Mail so Demarkis and I zipped over there to pick them up, I forgot to bring the damn credit card so no core refund, I brought all four batteries home and have the newest one made in January 2022 on the trickle charger now, I'll install it tomorrow and return the cores and hopefully get my core deposit back .

IIRC the Wallymart one was within $5 price wise and rated less so I think (hope !) I did okay, we'll see .

The second one was manufactured in December of 2021 so they're nice and fresh .

Once I get the wagon (S.W.M.B.O.'s car so first to be fixed) running I'll test the alternator output, it may be time to replace the voltage regulator and brushes, I keep spare BOSCH ones on hand as spares always, I did the off brand thing, they all suck, even the various German made ones ~ ONLY BOSCH or HELLA brand ones will give you the proper charge rate .

Stand by to see what happens next ~ I hope they'll go right in and work fine, we'll see .

vwnate1 · #6 02-28-2022, 08:04 PM

O.K., after 12 plus hours on a trickle charger I installed the battery to the wagon and lit it off, the voltage zoomed right up to 14.+, I shut it down and later took it out for errands to see how it goes, it's now charging at 13.7+ on the throttle, drops to 12.6 at idle at stop lights so it's good to go .

The other battery is slow charging right now, I think I'll pop it in Wednesday .

BillGrissom · #7 02-28-2022, 10:31 PM

Like many here, I use an H8 battery in my 300D's. Don't know if your coupe and wagon differ. The H8 was ~$25 cheaper and 10 lb lighter compared to the "correct" Frame 49 at Autozone. I recall it specs the same or higher CCA, but regardless it rarely freezes here so hasn't bit me.

If you really want to be a big spender, forget the AGM and get one of the new Li batteries, as show car guys do. Will set you back ~$650. I read that Tesla will start using one for their 12 V battery instead of lead-acid type, but battery-cars and hybrids have a half-size battery so perhaps cheaper for them (thought current small lead-acid hybrid batteries are actually pricier). If a cheap bastard and/or shocked by current battery prices, watch youtubes on restoring a battery using a high-amp welder if you have one. Some large chargers have the function built-in. It often works to kick the sulfate off the plates.

vwnate1 · #8 02-28-2022, 10:53 PM

Thanx Bill ! .

I wonder if maybe the AGM one wasn't bad, just discharged from sitting too long ~ almost a year .

barry12345 · #9 03-01-2022, 08:38 AM

I buy more batteries than otherwise would be the case by having them not in service often enough. How does interstate sell used batteries with some indication they are still really good? The factory owned places have a battery checker that reads far more information on a battery than we have any ability to do. Possibly the internal resistance as well. With time as that builds up it is unable to deliver current.

They are not taking the batteries apart for real rebuilding. If one qualifies to be resold. They fuly charge it and check for bleed down after a week perhaps. Low to none and it passes a load test then it is probably almost as good as new. No ideal of where they come up with so many resellable duds. At times like when they are out of the type I want. I get a new battery instead at teh same prices I suspect very strongly. I call them seconds but they load test as they should. Cases are obviously brand new. Not just cleaned. They can do trhis speaks strongly of their internal costs of manufacturing them.

I am sure members know. At a retail outlet where they have many examples of the same type battery in stock. Look at the date labels on them. Many times the one at the back of the rack will have the newest date.

One constant in my life is I found a brand of battery I liked at times over the years. Only to see it discontinued when I wanted another the same a few years later.

Also a new kink is to change the battery on an age basis in the newest vehicles. My interpretation is when it still works well but will not high load test anymore. Modern cars can have issues caused by running batteries like most of us do. Until there is evidence they need changed just by the way they crank the engine. I notice in some of my manuals that this is now a required practice. My guess is there is not enough voltage available to meet the other needs of the elecronic system if the cranking is pulling the voltage down too far. Just a guess that makes some sense to me perhaps.

There are other possibilities and considerations. Some starters are now so small they have not got enough mass to avoid rapid heating up. You do not want to buy a new alternator on some of these newer cars until you are certain it is the issue. Or create the issue. No longer as easy to establish on many cars. I do not know if there is a rebuilt available for our 7-800.00 alternator on one car.

vwnate1 · #10 03-01-2022, 09:46 PM

I may have made a serious mistake turning in my stone dead AGM ~ I'd thought about connecting it with another good battery in parallel before connecting the charger, I googled it tonight and supposedly one should do this to try before tossing it out .

I used those Intersate 'used / new' batteries, for a while I had very good luck and put one into every used car I built because I don't like comebacks .

Then several failed , didn't keep a charge over a week so I stopped .

I prefer one and done .

barry12345 · #11 03-01-2022, 10:55 PM

I expected more of a problem with them than I am experiencing. May be the quality of the staff at an interstate owned factory outlet. I know that non factory owned retailers can get them. Plus see no reason they could not sell used batteries claiming they were from interstate.

I have no ideal of what that battery checker the interstate factory outlet had. Never saw anything like it anywhere else.
It does more than voltage and load checks. In fact it could not do load testing.

I suspect without actually knowing internal resistance is one of them. Natural internal resistance increase with deterioration. All I know is they cannot keep up with demand.

Old rule is never leave a battery sitting on concrete. When not in service. I am like you Nate. I will keep buying them until they are a problem.

There is only one positive way to store a lead acid battery. It is messy. Remove the acid and put it back in just before reuse. This is how the American military does it. At least the naval arm.

ykobayashi · #12 03-01-2022, 11:27 PM

I buy the MAX-H8 batteries from Walmart. They are around $150.

I don’t know if they’re good or bad. I feel I get what I pay for kind of like most things I get at Walmart. They work but they’re nothing extraordinary.

ETA-I went out to the garage and they say 900CCA on them. They seem to do the job. My cars run pretty well so it doesn’t take much to fire them up.

vwnate1 · #13 03-02-2022, 09:27 AM

That's one of the ones that died .

ykobayashi · #14 03-02-2022, 11:41 PM

Yeah well they’re cheap. I have a four year old one in my blue 300d. It discharges if I leave the car off the trickle charger a month. I should check the draw. It could be the car or it could be the cheapo Walmart battery.

My feeling is these last me six years unless I do something dumb like discharge them accidentally. When they start getting anemic cranking I swap them out fast. They don’t give much warning.

I use these in most of my cars. I make sure to never let them go dead. That’s been a chore during the pandemic because we drive less. I seem to be able to really kill them quick if they’re left discharged.

vwnate1 · #15 03-03-2022, 12:56 AM

Thanx ~ up until now I too have gotten 6 years or more out of every battery .

I'm thinking I killed that AGM one, bummer that

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I agree about the slow cranking meaning is getting ready to fail, for some reason my 240D always is find right until it won't crank, usually in the dead of August far from home in the Desert where it's at least 100* F .

They're not cheap ! .

I don't have much $ being retired and on a fixed budget .