**************.com recommends Optima Red Top batteries.

Do Peach-Parters concur?

If so, which Optima Red Top works for 1985 300D?

Their eq of a 49 should sure do it.

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1985 300D 198K sold
1982 300D 202K
1989 300E 125K
1992 940T

"If you dont have time to do it safely, you dont have time to do it"

"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."

I hear good things about Optima batteries, but they use a gel instead of a liquid inside. Best uses are for off road or boat applications, as the gel doesn't slosh around. You can mount those batteries at any angle.
I have an Interstate unit in the SD, came with it five years ago, still cranking fine.
I bought a battery from Advance Auto, the Titanium ~$12.00.

You need a group 49 battery, don't use a deep cycle battery, those are not designed to be continually charged, but drawn down to near "empty" and recharged fully.

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83 SD

84 CD

Optima doesn't make an equivalent to a BCI group 49 battery.

Try Decca AKA East Penn Manufacturing. They are still made in America not in Mexico or China.

The Optima batteries do not have gel in them. They use an absorbent glass mat. It's a fibrous mat that's used to hold the electrolyte. The electrode is then rolled up in the glass mat. that's why they have more CCa than a typical wet cell bat. More surface area between the electrolyte and the eletrode. This is also why they can be turned and direction.

Deka AGM 12VDC 95AH Battery Group 49 - 9AGM49

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Mad_Matt's Current Stable:
Oil Burners:
09 Jetta TDI The highway queen @ 105k
83 300D. Sold
Gassers:
16 A4 sport line
10 Passat
83 Recaro Trans AM WS6 Bone Stock Survivor
11 Harley Ultra

^Thanks for the correction.

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83 SD

84 CD

There has been lot's of discussion on Optima batteries on Jeep sites. The overwhelming consensus is that the quality of the Optima battery is not what it once was. Lot's of folks who had great success with the original offerings are not at all impressed with the more recent (not made in USA) units.

I don't think they are well suited for a diesel. They don't have the amp hours of a quality conventional battery.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

I cannot find the article but I read one that said unless the Voltage Regulator on a Bosch Alternator can put out 13.7 Volts or more it will not charge an Optima.

I have had no experience with the above so cannot say it is true.

I did a google search = Optima battery needs a minimum of 13.7 volts to charge

"At one time Interstate offered a line of "Extreme Performance" batteries (9). Recently they reappeared on their Web site under the name "Optima Spiralcell", so they may have a cooperative agreement with Optima. Optima has added a little silver to the plates and some sodium sulfate in the electrolyte, and fabricated the lead plates in a spiral. Their main claim to fame is their ability to be charged very quickly, allegedly due to the greater surface area of their plates and the ensuing lower internal resistance (on the order of 3 milliohms). Since there is no way to add water, they may be lead/calcium (+silver), and the higher charging voltages would apply.

Their charging advice supports this theory. They suggest that alternator settings anywhere from 13.8 to 15.0 volts are appropriate, but that they can be rapidly charged at as much as 15.6 volts. Elsewhere in the same document it is suggested that for constant-voltage charging 14.7 to 15.0 VDC is correct (supporting the "lead/calcium" hypothesis). "

The above came from a long article on battery Charging:
http://www.landiss.com/battery.htm

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84 300D, 82 Volvo 244Gl Diesel

Just get a Duralast group 49. They are the best bang for your buck. Seeing as all batteries in this country are made by either Johnson Control or someone else.

You could always spend, probably $30 more and get the official white battery from the dealership. Get something with at a minimum 850 CCA. The higher the better. I think mine is an 850 since I live in FL but for up north you will want 1000 CCA.

A sealed, gel battery is only good to use if the battery itself has to be placed inside the car. Such as in a Delorean where the battery sits behind the passenger in a compartment, on its side!

Walmart (yuck) actually has the correct battery for our cars. When I looked a few weeks ago it was only $98 and has a 3 yr free replacement warranty. Battery is made by johnson controls and looks just like the battery we got from O'reilly's for ~$129 a month or so ago (DOH!).

Bottom of battery is white/semi-transparent and top is black. The battery has handles in the middle that fold back in to the battery. Next time I need a battery for one of the W123's it will probably be this one.

On a side note, when I got my car and started working on it. I wanted a cheap battery just to have handy. I found a "re-certified" battery from my local interstate dealer for about $30. It's not the correct size but I made it work. Cranks the car just fine and has been in there for 2 years now with no issues. We have another one in my father-in-law's 240D that has been there for 2 yrs. Warranty is only like 60 or 90 days but for $30 I'm a happy camper

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'98 E300 Turbo "Juliette"
'85 Federal 300TD

My local Interstate battery guy sells group 49 blems cheep tooo. IIRC last quote was $35. I really dont care if the case is discolored.

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1985 300D 198K sold
1982 300D 202K
1989 300E 125K
1992 940T

"If you dont have time to do it safely, you dont have time to do it"

"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."

I'll give you an honest opinion. I worked for JCI so literally EVERYTHING I drive has an Optima in it.

As cool as they are for most things, they don't seem to be much good on the Diesels. I have Yellow top 34R's in the truck and a Red top 34R in the car. If you drove within the last day or so, they deliver fantastic starting power. Any longer and the cranking power drops off dramatically. You can literally hear the engine cranking slower.

They just don't have the balls for a higher compression engine.

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-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

Our shop does quite a bit of track car fab/prep etc, so many of the customer cars will have optima batteries installed and in many cases we replace them with either a Odyssey motorcycle battery or Interstate stock fitment battery. In my experience, Optimas seem to have a high failure rate compared to almost any other battery on the market.

I've had an Optima in my E300 for about eight years with no issues. Since it is under the rear seat, I wanted something that wouldn't outgas - worked so far.

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Len
'59 220S Cabriolet-SOLD and living happily in Malta
'83 240D 351,500 miles original owner-SOLD
'88 560SL 41,000 miles - totaled and parted out
https://sites.google.com/site/mercedesstuff/home
'99 E300 turbo 227,500 miles
'03 SLK320 40,000 miles - gave to my daughter
'14 Smart electric coupe 28,500 miles
'14 Smart electric cabriolet 28,500 miles
'15 Smart electric coupe 28,000 miles