[sokoloff]

After the discussions we've had here about the EV battery "bricking" in conjunction with the 12v battery going dead, I've decided to do a preemptive strike and just replace my 12v battery to head off any potential cata$trophe. I'm seeing no issues and I have had the service campaigns done, but the battery is original to my 2014 coupe. This goes against everything I've ever done in the past when I waited until the 12v battery told me it was time to be changed. I would often go as long as ten years, but there was little downside. That may no longer be the case with our Smarts.

So I'm seeking input from those of you that have changed the battery. Looking for things to watch out for and things to make the job go smoothly. My plan is to hopefully install the correct battery from Mercedes to avoid any issues with size and fit. I think that some of you have used a Group 47 battery, but I've read reports of some having to make some modifications in the hold down, etc. I figure those issues can be avoided by using the correct Smart battery. It's a very tight fit no matter the battery used. Cost is about $170 which isn't that much more than a battery from a McParts store.

Does it make any difference if the EV battery is fully charged or not when replacing the 12v battery? I've seen one You Tube video where it was suggested that the plastic cover in the center between the passenger and the driver's side be removed, but I've seen others where that wasn't necessary.

Any advice and experiences appreciated.

Thanks.

Len

2014 EV Coupe 19,500 miles
2014 EV Cabriolet 17,500 miles

 

[yblocker]

I wound up buying the Mercedes battery for my 2014 for the same reasons you state.
Very straightforward job. Didn't even loose the rdio pre-sets.

 

[sokoloff]

Good to hear - thanks.

Len
2014 EV Coupe 19,500 miles
2014 EV Cabriolet 17,500 miles

 

[MB DNA]

Although your two "garage queens" and mild climate may not dictate a need for replacement, that unknown time outdoors as lot inventory may have impacted their "as new" 12V batteries. Probably a wise bit of "battery insurance" to replace before failure that may or may not be impactful to the HV battery?

Since MY 2008 - now with 3 smarts (all changed 2 lead & 1 gel) in the fleet I have not been impressed with M-B branded batteries.

The warranty listed below may not be applicable to our "orphan brand" and may include only Mercedes-Benz Passenger Car, Light Truck or Sprinter?

M-B WARRANTY PERIOD:1. Original (Factory-Installed) Battery: The warranty period is for 48 months or 50,000 miles, whichever comes first.2. Replacement Battery:2.1 If a replacement battery is installed while the vehicle is under the terms of the Limited Warranty for Original Installed Battery (see 1), the replacement battery is warranted for the remainder of the original

installed battery warranty terms.2.2 Any replacement battery purchased on or after August 1, 2000 at total customer expense is covered for a warranty period of 24 months, unlimited mileage from the date of purchase. Warrantable repairs will be made at no charge for parts and labor when performed at an authorized Mercedes-Benz Center (Passenger Car, Light Truck or Sprinter / Commercial Vehicle, as applicable).2.3 If a replacement battery purchased prior to August 1, 2000 at total customer expense becomes defective, it will be replaced free of charge during the first 24 months from the date of purchase.

 

[sokoloff]

My thoughts exactly regarding the battery insurance. Plus there is a note in my coupe's VMI that the battery had to be recharged when someone left the radio on. If I had all the info I have now about the HV batteries "bricking," I might have passed on the car. Glad I didn't, because it has given us four and a half years of excellent/fun service so far. I couldn't see a date on the battery, but I assume it is the original. If so, it has served us well. Mercedes batteries used to be Vartas. Not sure if that's what they still use or not.

Len
2014 EV Coupe 19,500 miles
2014 EV Cabriolet 17,500 miles

 

[letoon]

After the discussions we've had here about the EV battery "bricking" in conjunction with the 12v battery going dead, I've decided to do a preemptive strike and just replace my 12v battery to head off any potential cata$trophe. I'm seeing no issues and I have had the service campaigns done, but the battery is original to my 2014 coupe. This goes against everything I've ever done in the past when I waited until the 12v battery told me it was time to be changed. I would often go as long as ten years, but there was little downside. That may no longer be the case with our Smarts.

So I'm seeking input from those of you that have changed the battery. Looking for things to watch out for and things to make the job go smoothly. My plan is to hopefully install the correct battery from Mercedes to avoid any issues with size and fit. I think that some of you have used a Group 47 battery, but I've read reports of some having to make some modifications in the hold down, etc. I figure those issues can be avoided by using the correct Smart battery. It's a very tight fit no matter the battery used. Cost is about $170 which isn't that much more than a battery from a McParts store.

Does it make any difference if the EV battery is fully charged or not when replacing the 12v battery? I've seen one You Tube video where it was suggested that the plastic cover in the center between the passenger and the driver's side be removed, but I've seen others where that wasn't necessary.

Any advice and experiences appreciated.

Thanks.

Len
2014 EV Coupe 19,500 miles
2014 EV Cabriolet 17,500 miles

Hello, did you figured it out the correct procedure to change your 12v battery safely?
I am at the same point that you, 2014 Fortwo coupe with the original battery, I believe I need to change it soon (especially because I live in Vegas, and hot hot summer!)
My mechanical advised me to stick with the OEM battery, believing it's a AGM battery. But after my research, it's not. Regular lead battery...

So I found one OEM on ebay from Florida, for $195 with the delivery (decent price compared to the $218 at my local MB dealership without installation) but both expensive for a no AGM battery...
So my question, should I buy a OEM battery and change it myself? Or go to Pepboy, spend $123 and get a "Champion Premium Battery, Group Size T4" with the installation included (but probably with guys who never work on EVs...)
May be get an AGM battery? But I didn't find any auto store (Autozone, OReilly, Pepboys) with one would fit on the Fortwo.

If I would change myself, how to proceed properly?

Thank you for your help!

 

[sokoloff]

Up in the stickies is the procedure for changing the 12v battery. Not terribly difficult and no special procedures. Just don't leave it out for days. I did the OE battery only because the aftermarket batteries are slightly larger and you might have to modify the hold down clamp. That's not a terrible job, but I just didn't want to mess with it, the hold down that is. My battery was $173 at the dealer. Lots of dealers will give you a veteran's discount.

Len
2014 EV Coupe 20,000 miles
2014 EV Cabriolet 18,500 miles

 

[JoeReid]

Up in the stickies is the procedure for changing the 12v battery. Not terribly difficult and no special procedures. Just don't leave it out for days. I did the OE battery only because the aftermarket batteries are slightly larger and you might have to modify the hold down clamp. That's not a terrible job, but I just didn't want to mess with it, the hold down that is. My battery was $173 at the dealer. Lots of dealers will give you a veteran's discount.

Len
2014 EV Coupe 20,000 miles
2014 EV Cabriolet 18,500 miles

I replaced the original 12 volt battery in my 2013 ED this morning. The replacement I used is a ACDelco LN1H. I bought it from Wheeler Bros., Inc. in Somerset, PA (866-439-2329) for $105 shipping included. It is not only an exact fit but appears to be made by the same manufacturer as can be seen in the images. There are vent holes on both sides so you will have to use the plug from your original battery on the side closest to the front of the car. The only difference I can notice it that the new battery does not have the electrolyte level window on top and the warrantee is full replacement for 30 months and I believe the OEM battery is only warranteed for 12 months and costs more than twice as much. The most difficult part of the replacement was lifting the old battery out. It is way down in the passenger side foot well and I’m an old guy with a bad back. You may notice that I added a charging cable so I can use a Battery Minder (smart maintainer) when the car is not expected to be driven for more than a week or two. When the installation was complete everything worked as with the OEM battery including the radio station memories. Thanks to Len and Jim Sokoloff for encouraging me to make this replacement before my original battery died and possibly bricked my motive battery.

 

[sokoloff]

Wow Joe - thanks for posting the photos - sure looks identical to the original. Used to be that Mercedes used Varta as their battery source. On my new OE battery I looked hard for a manufacturer, but couldn't find one.

Len
2014 EV Coupe 20,000 miles
2014 EV Cabriolet 18,500 miles

 

[letoon]

Wow Joe - thanks for posting the photos - sure looks identical to the original. Used to be that Mercedes used Varta as their battery source. On my new OE battery I looked hard for a manufacturer, but couldn't find one.

Len
2014 EV Coupe 20,000 miles
2014 EV Cabriolet 18,500 miles

Great catch JoeReid.
Now I need to find where I can find this battery close here. The regular auto stores don't seem to have it... if not I will contact Wheeler Bros.
Thank you!
It's still possible MB and ACDelco use the same provider for their battery, maybe from Varta, and change the sticker.

 

[lebikerboy]

Has anyone replaced the 12V battery in a 453 yet? The location where it's sitting looks like it's going to be a real bear to get out...

 

[MB DNA]

May be get an AGM battery? But I didn't find any auto store (Autozone, OReilly, Pepboys) with one would fit on the Fortwo.

AGM NG47 at Advance Auto (oops)...

Amp Hour:	60.0 AH
Cold Cranking Amperage:	680 A
Cranking Amperage:	850 A
Height:	7.5 in
Length:	9.562 in
Negative Terminal Location:	Top Left
Positive Terminal Location:	Top Right
Reserve Capacity:	100 min
Terminal Type:	Top Mount
Voltage:	12.0 VDC
Weight:	39.6 lb
Width:	6.937 in

 

[letoon]

I never changed it yet, but I will in few time...
I ordered online LN1H Battery Asm
Thank you JoeReid

 

[letoon]

AGM NG47 at A’zone...

This one would fit? or I should bend the holder?

 

[letoon]

AGM NG47 at Advance Auto (oops)...

Amp Hour:	60.0 AH
Cold Cranking Amperage:	680 A
Cranking Amperage:	850 A
Height:	7.5 in
Length:	9.562 in
Negative Terminal Location:	Top Left
Positive Terminal Location:	Top Right
Reserve Capacity:	100 min
Terminal Type:	Top Mount
Voltage:	12.0 VDC
Weight:	39.6 lb
Width:	6.937 in

Great, thank you

 

[Vincent Rapide]

I would not want a "flooded lead acid" batt inside my car for the fumes to mingle about. Just to save a couple hundred buck$. But you may say, even AGMs have a tiny breather vent. Still . . .

Has anyone clamped a dc ammeter to the 12v batt lead to monitor max amps during normal driving conditions? I'm set to do this but wonder how I can view the small screen on the meter while driving. I'm guessing maybe the max draw might not be the full [~60ah] ever (??). What would cause such a heavy 12v draw? The heater and AC work off the hv batt.
--

 

[JoeReid]

I would not want a "flooded lead acid" batt inside my car for the fumes to mingle about. Just to save a couple hundred buck$. But you may say, even AGMs have a tiny breather vent. Still . . .

Has anyone clamped a dc ammeter to the 12v batt lead to monitor max amps during normal driving conditions? I'm set to do this but wonder how I can view the small screen on the meter while driving. I'm guessing maybe the max draw might not be the full [~60ah] ever (??). What would cause such a heavy 12v draw? The heater and AC work off the hv batt.
--

I'm not concerned with fumes from the electrolyte because my new battery has a vent tube on the back side and the vent on the front is plugged so any vapor should be dumped outside the car as it was with the OEM battery. Please share the current through your 12 volt battery, the max current in both charge and discharge if you are able to measure it,

I have two ICE cars ("88 Honda and a "99 Porsche) both of which have AGM batteries that are more than 6 years old and still crank the engines with vigor. Because those cars have robust charging systems they don't seem to be effected by the high charging current drawn by the lower internal resistance of the AGM batteries. I wonder if the DC to DC converter in the Smart ED can survive the the charging current required by an AGM battery. Any one out there with long term AGM battery experience in a Smart ED like to share their experience?

 

[Vincent Rapide]

My Spark has an AGM but apparently not so the Smart. Hmm.

Instead of trying to read a clamp-on dc ammeter in the Smart while driving, instead I will measure the voltage across the neg post shunt and then align the volt scale to coincide with amps shown on the clamp. Then maybe mount the meter on the dash.

VR
--

 

[Vincent Rapide]

Got no readings across this shunt. So I'll hookup a small float charger to my aged 12v batt and leave the 12v connected while I'm away for a few weeks. What could possibly go wrong?
VR
--

 

[JoeReid]

Got no readings across this shunt. So I'll hookup a small float charger to my aged 12v batt and leave the 12v connected while I'm away for a few weeks. What could possibly go wrong?
VR
--

I left a Battery Minder connected to my original 12 volt battery for months over the last 6 winters with no deleterious effect. I kept the motive battery between 50% and 70% during those periods. The only reason I replaced mine was to preclude the eventuality of a failure that might lead to motive battery bricking,