I have battery tenders on both my 240D and 300Sd when I'm not driving them for a day or two. Could be the middle of winter or height of summer, they'll be plugged in.

Has anyone else had experience with battery tenders and how long should I expect my batteries to last. Both are currently at ten years, both Interstates. I know batteries have a finite life and Battery Tenders shoudl extend that life, but what kind of maximum life are others seeing out there?

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1977 240D
1981 300SD

Cool that this was posted, because I installed a battery tender/desulfater on the 300sd YESTERDAY. I guess I have a long way to go for giving an evaluation though. Lol

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1982 300sd from craigslist $800 greased on one tank with NO CONVERSION in the Hot Texas Sun. (currently dead & awaiting engine damage investigation and/or longblock swap)
new daily: '03 vw 5speed jetta tdi wagon. bagged&chipped

You, Sir, are leading a charmed life if your battery is still functioning after 10 years. In my case my 7.5 yr old '85 300D battery was working fine until last week it just quit after sitting in the garage over night. It was fortunate that it quit in while it was in the garage because the prior day I'd been out in the desert near Tucson, Az at a shooting range. The shooting range was at least 15 miles from the closest town! I bought a proper replacement from O'reilly's. The best and biggest they had and while it was still less than the MB dealer, it was still almost $150! Start saving up!

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Pete Williams, President emeritus - MBCA-International Stars (Eastern Mich.) Now Wi. & Az.
1985 300D Manual 4 speed Green Hen's tooth
1979 MGB triple black Az car nice
1969 back 1/2 of MGB (Az home built trailer)
1991 Volvo 245 Wagon Nice AZ Restored Gold Brick
1983 Jeep CJ7 37,600 Miles Summer use only

Hey Pete, I like to think I lived a charmed life I've always heard or believed the marketing that these things extended batter life but was wondering what the envelope is off of prior experience.

Having lived in Phoenix for a few years I know how hard summer can be on batteries. Seven and a half years sounds pretty good. During our harsh winters my cars Battery Tenders are plugged in so I don't have long glow cycles followed by the additional draw of starting the cars.

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1977 240D
1981 300SD

Yep, I do lead a charmed life Having lived in Phoenix for a few years, seven and a half years with your summers is doing pretty well.
At least during my winters the battery tenders are plugged and the cars started very once in a while. Still wondering what the outside of the envelope is when religiously using battery tenders.

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1977 240D
1981 300SD

Ten years

Must be working. The oldest battery I've had that still worked was a 9 year old in a Suzuki Samurai. The fact that the battery was almost the size of the engine probably helped. Most of the cars I've bought needed a battery replaced in the first year or two, and the battery I bought was still good when I got rid of the car. I've only had a few cars long enough to put more than one battery in them, and that usually came after I'd done something abusive to the battery such as letting it go dead more than a couple times.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

If you are seeing ten years with whatever you are doing. Plus especially if the car is not in constant daily use. You have it made in the shade.

High ambient temperatures in the more arrid regions are also hard on batteries I have heard. So much so the batteries intended for sale in those areas are a little differant I have also heard. May just be random hearsay though.

Group 49, the battery for at least the w123, Interstate blems are bout $40 out the door.

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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."

How much does it cost to run a battery tender for ten years?

Where are these available? Thanks

If it is the 1.25 amp model, running it at full capacity for one year would come to 131 kilowatt hours which at .10 would be about $13 per year and about $19 per year at .15 However the Tender does not charge at the full rate when it has reached the maintainence stage, so I would say the actual operating costs would be far less. However you would also need to factor in the cost of the Tender itself and how long it will last.

I don't use mine to save money though, I use it more for the convienence and dependability, I know if I leave that vehicle sit I won't have to drag out jumper cables next time I want to use it. I use it on my F350 which has constant parasitic loads when shut down. Plus 2 batteries, not cheap to replace.

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Brian
87 300Dturbo 180K #14 head still running R-12 SOLD 12/2017
02 F350 Powerstroke 180K
05 Chevy Express 1 ton w/Royal Utility box 120K
08 Infiniti FX-35 40K
15 Golf Sportwagen TDI 35K
10 Sprinter 3500 chassis with a Class A Winnebago on it. 56K

a battery desulfator uses no external power

I have 2 years on this desulfator on a new battery, will let you know it 10 years how it is going

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1999 Mercedes E300TD daily driver sold at 238K miles 106K miles were mine, rust worm got it :-(
2006 Mercedes CDI new daily driver! 56,000 miles May 2016 now 85,625 Apr 2018 and Apr 2019 101,000 miles Apr 2020 109,875. March 2024 135,250

I would not trust the battery tenders sold at Harbor Freight Tools. I use a quality tender that was bought from my local battery store (don't remember the brand). It was around $35.00, but worth the price.

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All Diesel Fleet
1985 R107 300SLD TURBODIESEL
2005 E320 CDI (daily)

LOTS of parts for sale!


EGR block kit
http://www.peachparts.com/shopforum/diesel-discussion/355250-sale-egr-delete-block-off-plate-kit.html

1985 CA emissions 617 owners- You Need This!
Sanden style A/C Compressor Mounting Kit for your 616/ 617 For Sale + Install Inst.

Sanden Instalation Guide (post 11):
http://www.peachparts.com/shopforum/diesel-discussion/367883-sanden-retrofit-installation-guide.html

Deltran makes the best

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Brian
87 300Dturbo 180K #14 head still running R-12 SOLD 12/2017
02 F350 Powerstroke 180K
05 Chevy Express 1 ton w/Royal Utility box 120K
08 Infiniti FX-35 40K
15 Golf Sportwagen TDI 35K
10 Sprinter 3500 chassis with a Class A Winnebago on it. 56K

I would like to know if tender battery connected to the posts under hood in 2012 ML 350 may damage the ISM.

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Juan