What Battery Do You Have in Your 355?

Why not solar? They do make them for small applications. Battery Mart carries them. I do not know how well they work though.

5-Watt Solar Panel by Battery Tender: BatteryMart.com

 

When out and checked the 13 year old battery in the 308. As I said above, I just disconnect it and let it sit. Measured 12.4 V which indicates about 75% of full charge. Seems pretty good for such an old battery that has been sitting for 3+ months.

Of course, I am not advocating not using a tender if you leave your battery connected, or even if you disconnect it. Just reporting my experiences.

 

I use that on my diesel with 3 batteries because it can sit for a weeks at a time. Works great.
Just remember to get one with a regulator in it like that model, lots of cheap one's don't.

 

The only reasons solar charger isn't an option for me is my parking stall is in the interior of the garage. No sunshine.

 

Battery tenders do have extension cords available for them.

25 Foot Extension Cable: BatteryMart.com

Tim has one of the solar tenders and is very happy with it.

 

I replaced my battery with a Bosch from Pep Boys last year and always keep it plugged in with a Battery Tender Jr. I think the battery was around $150ish and has a 5 year warranty.

 

In doing the wheels off detailing, I've worked my way to the battery compartment. I decided to go ahead and replace the 5 year old battery while I was there. Went with the Interstate MT7 34R. An AGM battery that won't leak and while I was there, I installed the pig tail for the Ctek Battery maintainer. Now on to the next task. --- mosierjr
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The replacement for the Interstate 34R is a 36R

 

That's good to know thank you. I was told the 34r was dc. There may be some left in old inventory.

 

Must be some miscommunication somewhere.

All stores had Megatron 34's in stock, and my AGM Mt7 34R has a manufacturing date of Jan 2015.

Just for clarification, so everyone understands, the 34 in the notation is a Size Group which can't be superseded. Group 36 is a different size. While you may be able to fit more than one size group into a given application, they are different physical sizes regardless of manufacturer or battery model type. Millions of cars will require group 34 size batteries as replacements for years to come.
View attachment Specification+Sheet+-+Batteries.pdf

 

Good news, the Interstate MT-34r is still available. I picked mine up today.
Now I just need time to swap it out. Is there any tricks to changing the battery? Does the battery switch need to be turned off? Does anything need to be done to the alarm once the new battery is installed? Any other tips, suggestions, concerns?

 

I turned the switch off because I wanted to clean/wax the headlights in the up position while i was doing the battery. No issues noted turning it back on and starting the car. Just remember to let it idle for awhile to re-learn the ECU.

FYI All - I noticed in the drivers manual (1996) the positive battery terminal is on the left, which would NOT be an R version battery. However, I also noticed while installing the battery that the cables come down from above the battery and are plenty long. It would be just as simple to hook up an "R" (reverse terminal) battery, or a non-"R" battery. It won't make any difference which one you buy.

Also, There is a little extra length and height available for the battery, so while most people put in a Size Group 34 battery, others may fit as well. ---- mosierjr

 

Has anyone tried this? Doesn't look as strong as the 34R, which was discontinued a year ago.

36R:

Cranking Amps: 810
Cold Cranking Amps: 650
Voltage: 12
Termination: A
Weight (lbs): 39
Length (in): 10.38
Height (in): 8.88
ReserveCapacity-25: 130.00

34R

Cranking Amps: 875
Cold Cranking Amps: 700
Termination: A
Voltage: 12
Width: 6.88”
Length: 10.25”
Height: 7.75”
Weight: 37.40

Anything better out there?

 

Yes, Bosch 34. Got mine from Pep Boys

Cranking Amps: 950
Cold Cranking Amps: 770

Bosch Premium Performance Battery Group Size 34 | Product Details | Pep Boys

 

Sears Platinum AGM is a good option. Available in 34R and around $165 (on sale for $150 right now) with three year free replacement warranty. Totally sealed, no vent tube needed. 775 CCA

It is also sold at Sams Club under the Duracell brand name...probably for even less.

 

just viewed the interstate site and they appear to have discontinued the mt34r as stated by others but they still sell the mt 34 and as the battery cables are long enough in the 355 this battery will work as well. the price is only $122.00 (vs $258.00 for the agm 34r)

 

I picked up a Interstate MT-34R in January in Hawaii. I heard they were discontinued also. Did some research and found out otherwise

Good luck

 

If you look in the compartment you will see the cables come down directly from above and will just as easily connect to an "R" batttery or a non "R" battery. I don't know where this "R" version recommendation started. Even my 1996 owners manual does not show an "R" battery installed.

Interstate also make the MT7 AGM type in a 34 size that is superior for a little more money. There are many good choices in batteries, just don't get hung up on the "R" designation (which only reverses Pos & Neg sides), it makes no difference in a 355.

 

I know Ferrari Of Beverly Hills Replaced all of the batteries in new cars with Interstates before delivery..I have a Bosch in mine now

 

seems that if you keep your car on a tender when not driving the battery NEVER goes bad. anyone with the same experience?

 

It seems as if you just put on a tender here and there and no problems

 

Have new glass mat tech battery in mine. Lighter than sealed lead acid.

 

Technology improves as time goes by. Just put this 10 pound lithium ion battery which has 1000cca and an auto disconnect feature that holds reserve starting power when the voltage goes down. Also holds 80% power after 1 year of no use. The price of these also have come down quite a bit where over the long haul the premium you pay is worth it. Image Unavailable, Please Login

 

1000 ca, no cca. Big difference in use. It will work until the battery begins to lose some capacity over time. It would be preferable to have purchased a larger one.
I have been using a lithium ion battery in my motorcycle for 5 years...only because I went a bit oversize, it still gives good service. It is rated at around 360cca, and still tests after five years at around 240cca, which is the oem spec, so still adequate.

I think the only reason all of the "high performance" battery sellers still use CA specs, is they are hiding behind the fact to match equal CCA performance will cost you way, way more.

 

Even though you may rarely need it, worth getting a lithium ion battery tender. Deltran offers some inexpensive ones that work well.