Good-fitting replacement battery

[ctaylor738]

One of the issues when replacing batteries is finding one that fits the tray and hold-down, has the posts on top (not lowered), and has the positive terminal on the right side.  After some searching, I found the Interstate MT-34R, which meets all these criteria.  I recently installed one in a 280SL and it's a perfect fit, but I had to disconnect the top oil cooler line to get it into position.  Disconnecting the hood strap and securing the hood spring provides additional room.

Interstate's territory manager told me that the MT-34 series is being replaced by the MT-36.  It has the same footprint but is 1/2" taller, which is not a problem for our cars.

http://www.interstatebatteries.com/Products/RT/PID-MT-34R(Automotive+Truck).aspx?dsNavigation=Nrc~id-3%2CN~4294784989-4290241168-4294750763&Title=Pure+Lead+MT34R+replacement++battery

Cheers,

CT

[Jonny B]

Chuck,

Tried the link as posted and got a page not found error from the Interstate site, tried a second time, and it worked?!? Don't know if it is my browser (Safari) or what, in case any one else had an issue, I used the mt-34r as the search string and got this link:

http://www.interstatebatteries.com/b/vintage-car/N-zihwpmZzihwsq?dsNav=Ntk~SearchGroup%7cmt+34r%7c3%7c,A~Part+Number

[Cees Klumper]

Have a look at reply #336 on August 10 in the 'what have you done to your Pagoda today' (I tried linking to that reply but could not find out how; I've seen otHers do it though):

" I put in a new battery. After some research, I chose the Bosch silver S4 005 type. €85 in the local (France) LeClerc supermarket. This type of course because of the specifications (AH and CCA) but also the dimensions and location of the + and - posts, and the brand itself, which has a good reputation and because Bosch supplied many parts to our cars originally as well. Perfect fit and hopefully many years of service ahead."

Fits perfectly. Someone else in the US posted he got a Bosch (S3 I think) yesterday, and that it can be ordered through the usual parts supply houses.

[49er]

 I installed a World Battery back in 2010 and have been very happy with it. I like the fact that it is black (other then the Logo on the side) and looks a bit more "original" then the more colorful batteries. The hold down bracket is original but many years ago one of the nuts loosened on the forward hold down rod and it fell off while driving down the road. I replaced them with the silver (non original) clamps that I bought at a auto parts store. I still have the remaining original rod.

John

[garymand]

Damn, lead is really getting expensive!  If price is a concern The lowest prices I've found are Sam' Club, Walmart and Costco. 

[jameshoward]

Is there a reason why you don't want to fit an original MB battery to the car? Just fitted a new (I think 85A) battery to my car. Don't have the PN right now but a search on here (Dewtree) will turn up the PN. About €100 in Germany. Terminals the correct way around, fits perfectly and it's OEM.

[Cees Klumper]

I read somewhere you have to stay close to original spec on the amperage, because the system is not designed to properly deal with much more or less? I believe the original Value on my car was 55 A so I'd really hesitate to go to 85 (isn't that for Diesel cars and such?)

[ctaylor738]

James,

If that question is directed at m, the Interstate replaced an "original" MB battery with screw-on caps that was causing all sorts of corrosion in the engine compartment, despite charging at 13.7 volts at highway speeds.  It had corroded the bracket, power steering line fittings, power steering pump, left horn, injection lines, etc.

Cheers,

CT

[Raymond]

The rating on a battery is the number of cold-cranking amps the battery can supply at full charge, not what it wants for charging.   The 55-Amp rating on the alternator is just the maximum it can provide.  It won't hurt to have a larger battery it just might take a bit longer to reach full charge.  Even a flat battery should not kill an alternator. 

[garymand]

In most cases the bigger the better, especially if you live in North Dakota or Alaska.  Batteries have reduced voltage as temps get colder and oil gets thicker.  At 30 below, a 550 CCA battery is not going to get a motor turning.

I just replaced a 1000 CA with a 870 CA in my 250SL/280 motor.  (approximately due to my memory) The problem you are facing is the same as if you have a small battery charger to charge your 500 CA battery when it is down to 50% charge.  

Your alternator has a regulator between it and the battery (and all the other stuff that might be on with the motor running) a 55 Amp Alternator can put out a whole lot more than 55 amps but the heat would make short work of it.  The regulator holds the maximum current draw to 55 Amps.  If your battery is low on charge, keep as much electronics, lights, and blowers off until the battery gets back up a bit, becasue head lights and fan motors pull a lot of current.  Each amp your car needs reduces the 55 Amps available to charge the battery.

A battery charger also has a regulator between the charging voltage and the battery to-be-charged.  Its a current regulator (as opposed to a voltage regulator.   )  If you are charging a 500 Amp battery that needs 250 Amps to get up to full charge, the charger holds the current to below the max rating of the charger per hour.  A 40 Amp charger will limit the current to 40 Amps and it will take a few hours to get the battery up to 460A.  Once the current draw is less that 40A, the regulator will begin reducing the current all the way down to a 'trickle'.

The wiring in your car is designed to carry the battery charging current plus maybe 100%, (at least that's how some of us were taught to design.  Like I think MB designers ensure 150K engines by designing to 300K miles.)  The wire carrying charging current to your battery should handle the 2x full alternator rating rating and it is usually not fused.  

Bottom line, you could jump start you car and leave the jumper battery connected until both were charged up again.  If the car battery is a 700 and the jumper is a 700 the only problem might be the wire size between the regulator and your car battery.  It needs to carry the full current, but the full current is limited by your regulator to what, 55 Amps?  You'll just use a lot of gas, OH, another point: At low RPMs like Idle, the alternator might not be turning fast enough to reach full regulated output.  That's why you might want to get the rpms up when jumpstarting a dead battery from another car.  

I have a friend with a huge stereo in his Bmw.  He has a second battery in the trunk.  I don't know the sizes, but I'd guess maybe 800 CA each!  Dumb, lots of money, no real benefit, and a lot of extra weight.  Bottom line for this question: the alternator doesn't care.  It doesn't even know there are 1600 CA out there somewhere.  It just cranks out the 55 to 75 (maybe) Amps Max.

So I hope I've laid tireless questin to rest  

 

[jameshoward]

James,

If that question is directed at m, the Interstate replaced an "original" MB battery with screw-on caps that was causing all sorts of corrosion in the engine compartment, despite charging at 13.7 volts at highway speeds.  It had corroded the bracket, power steering line fittings, power steering pump, left horn, injection lines, etc.

Cheers,

CT

No. I'm not talking about an old fashioned battery to which you have to add acid, etc. I mean a new MB maintenance free sealed battery that doesn't leak/corrode, etc. Have a quick search. I'm pretty sure there's a post a few years back to which Dewtree contributed (its does happen, God Bless him...) about a good MB battery for his being-restored pagoda. I got the same part. I can get you a picture at the weekend, but most if not all of the cars I saw at Essen this year used the same battery, including Mekatronic. (or however you spell it). That's why I bought it.

[garymand]

That will solve the problem too, just buy what everyone else is buying and don't worry about the other stuff.

[66andBlue]

... found the Interstate MT-34R, which meets all these criteria. I recently installed one in a 280SL and it's a perfect fit, but I had to disconnect the top oil cooler line to get it into position.  Disconnecting the hood strap and securing the hood spring provides additional room. ...

Hello Chuck,
I am surprised you had to remove the oil cooler line to get a 34R battery in.
I bought a DieHard AMG 34R battery and can get it in and out easily without removing lines or the strap. Of course it helps that it is lighter than a regular lead-containing battery.
Removed the brand label in the front and now I am waiting for a more vintage one.

[Baybear]

Well you could always buy the geniune MB replacement battery which still has the battery caps. #002541870126 but it it's crazy expensive at a list of around $280.00. The hold downs fit perfectly however. ( yes I bought one but my parts person reduced the price to 160.00 ,still stupid) but it looks good.
Baybear

[Cees Klumper]

Thanks Ray, Gary, very clear!

[JamesL]

I was at an event recently where there were a couple of stands selling Li-Ion car batteries such as the one in the link
http://www.demon-tweeks.co.uk/motorsport/batteries/super-b-b5200-lithium-ion-battery

Weight saving, and power seem "too good to be true" (unless you're a concoursy person) but I have not investigated any downsides/read reviews etc. Seeing as Boeing have them that have caught fire...

[ctaylor738]

Alfred,

The difference is that your battery has the strap, which probably allowed you to position the battery and guide it down.  Without a strap, the oil cooler line gets in the way of your right hand right at the critical moment when you are simultaneously trying to position and lower the battery. 

Cheers,

CT

[thelews]

you need one of these

[69280sl]

Alfred
Can the sticker on top be peeled off also?
Gus

[66andBlue]

Gus,
yes, it is removable.
What kind of decorative label would you replace it with?

[69280sl]

Alfred
None. I would leave the top of the battery black. I would also consider painting the case black with Krylon Fusion paint which is supposedly formulated for plastic. But maybe the case is some sort of poly.. which would not take any paint.

Not original, but it doesn't scream replacement. Just my opinion.

Gus

[66andBlue]

Hello Gus,
I am planning to remove the top label once I have figured out how to make the front black but in a way that it can be reversed should I need to claim any warranty.
Obviously in such a case I need to put the labels back on again and make it look like a DieHard battery.

[jameshoward]

Alfred,

How about a piece of black wrap? You should be able to get a local detailer to do that for you easily enough and the cost would be peanuts. It's easily removed.

James

[KevinC]

Of all places, Pep Boys sells many Bosch brand batteries in various sizes. I am told that they are probably made by someone else but look appropriate in our cars. The bracket in this photo was home-made though...