Best Car Battery for Smart – Top Picks for Every Model

ACDelco Gold 48AGM (88864541) 36 Month Warranty AGM BCI Group 48 Battery

Mighty Max Battery MM-H5 Start and Stop Car BCI Group Size 47 12V 60 AH, 100RC, 680 CCA Rechargeable AGM Car Battery

$149.99

Top Battery Types for Smarts (What to Choose & Why)

Type	Best For	Pros	Watch‑outs	Typical Price
Flooded (Lead‑Acid)	Older 450/452 or budget replacements	Lowest cost; widely available	Lower cycle life; weaker for heavy accessories	$120–$200
EFB	453 with start‑stop; mixed city driving	Better cycle life than flooded; OE on many 453	Don’t downgrade from EFB to flooded	$170–$260 (browse H5 EFB)
AGM	EQ/ED aux battery, short trips, high loads	High CCA; fast charge acceptance; spill‑proof	Slightly higher cost; needs proper venting	$220–$360 (see H5 AGM)
LiFePO₄ (Performance)	Weight savings, occasional track use	Very light; high cranking for size	Compatibility & cold‑weather limits; premium price	$500–$900 (H5 lithium)

Smart Model-Specific Buying Tips

fortwo 450 (1998–2006): Look for DIN L1 / 063 (~207×175×190 mm), ~42–50Ah. Compact case clears the footwell and hold‑down. Search 063 size batteries. ~$120–$180
Roadster 452 (2003–2006): Also DIN L1 / 063. Favor higher Ah (50+) if you run accessories. Shop L1/063. ~$130–$190
fortwo 451 (2007–2015): Commonly H5 / Group 47. If you have lots of short trips or accessories, step up to AGM H5. Browse H5. ~$170–$320
fortwo & forfour 453 (2016–2019): H5 / Group 47 is standard. Many trims used EFB from factory; AGM is an upgrade. H5 EFB or H5 AGM. ~$190–$350
EQ fortwo / ED (electric): The 12V auxiliary uses H5. Choose AGM for deeper cycling and cabin vent safety. See AGM H5. ~$220–$360

Smart Battery Fitment Cheat Sheet (Most-Common Sizes)

Model	Years	Common Size(s)	Tech (OE)	Notes
fortwo 450 (petrol)	1998–2006	DIN L1 / 063 (~207×175×190)	Flooded SLA ~50Ah	Compact footprint; verify hold‑down & vent path
fortwo 450 (diesel)	1999–2005	DIN L1 / 065 (~61Ah)	Flooded SLA	Higher Ah spec than petrol; sealed/vented design recommended
Roadster 452	2003–2006	DIN L1 / 063	Flooded SLA 42–50Ah	Small case; check B13 base clamp
fortwo 451	2007–2015	H5 / Group 47 / L2	Flooded/EFB (~50–61Ah)	AGM upgrade recommended for short trips
fortwo 453	2016–2019	H5 / Group 47 / L2	EFB (many trims)	Located under front hood; vent to exterior
forfour 453	2015–2019	H5 / Group 47 / L2	EFB	Shared platform with Renault Twingo; H5 fitment common
EQ fortwo / ED	2013–2019	H5 / Group 47 (12V auxiliary)	EFB/AGM depending on year	12V runs accessories & relays; high charge acceptance helps

Spec Targets: CCA, RC, and Warranty

CCA: Cold Cranking Amps RC: Reserve Capacity Tech: Flooded / EFB / AGM

CCA: Meet or exceed factory spec. For cold winters, aim +50–100 CCA over OE. H5/47 AGMs typically offer 650–680 CCA.
RC: More RC = better support for lights/HVAC/audio at idle or with the engine off. H5/47 often lands around 90–110 minutes.
Technology: If your Smart shipped with EFB/AGM (common on 453 and EQ/ED), don’t downgrade to standard flooded.
Warranty: Target 36+ months free replacement (policy varies by region and retailer).
Orientation & venting: H5/47 uses top posts; ensure the vent tube routes outside the cabin.

Best Car Battery Brands for Smart & Where-to-Buy

Brand/Line	Why It’s Good for Smart	Shop
Odyssey ODP‑AGM47 (H5)	Premium AGM, strong CCA & cycling for short‑trip city use	Search on Amazon
Optima YellowTop DH5 (H5)	Deep‑cycle AGM ideal for accessories and frequent stops	Search on Amazon
Interstate MTP‑47/H5	Trusted fitment for 451/453; robust CCA	Search on Amazon
DieHard Platinum AGM H5	Well‑reviewed AGM with long warranty	Search on Amazon
Duralast Gold / Platinum (H5)	Good CCA & availability; Platinum = AGM	Search on Amazon
Varta / Bosch H5	OE‑tier European options, especially for 450/452/453	Search on Amazon
Performance Lithium (H5 case)	Ultra‑light; niche builds. Confirm alternator/BMS compatibility.	Search on Amazon

Where to buy (US/EU): Amazon (fast delivery), AutoZone/Advance/O’Reilly (testing & install), Walmart (budget), MB/Smart dealers (coding/updates & OE parts).
Pro tip: Ask retailers to load‑test your old battery/charging system before you buy—often free.

How to Check Freshness & Authenticity

Find the date code (e.g., A=Jan → L=Dec; number=year). Prefer stock < 6 months old.
Confirm weight matches spec (very light can indicate low electrolyte in lead‑acid).
Inspect case & posts for scuffs, spills, crooked labels; avoid products with tampered vent caps.
Buy from reputable sellers; keep receipt for warranty.

Car Battery Warranty Tips

Look for free replacement period (e.g., 36 months) rather than pro‑rated only.
Verify the warranty is honored nationwide (handy on road trips).
Record install date, mileage, and voltage on the receipt or under‑hood label.
Follow required charging/venting notes; misuse can void coverage.

ACDelco Gold 48AGM (88864541) 36 Month Warranty AGM BCI Group 48 Battery

Weize Platinum AGM Battery BCI Group 24F Automotive Battery, 120RC, 710CCA, 36 Months Warranty, Dimensions 10.75" L x 6.81" W x 8.98" H

$199.99

Weize Platinum AGM Battery BCI Group 47-12v 60ah H5 Size 47 Automotive Battery, 100RC, 680CCA, 36 Months Warranty, Dimensions 9.52" L x 6.89" W x 7.48" H

Smart Car Battery Installation Guide (DIY or Shop)

Save settings & prep: Keep doors open, key out. If available, connect a memory saver to the OBD port to retain presets.
Access the battery: On 451/453, open the front service flap/hood; the battery sits ahead of the cabin (passenger side on many trims). Remove covers/trim as needed.
Vent check: Identify the vent tube and note which side it plugs into on the new battery.
Disconnect safely: Negative (−) first, then positive (+). Undo the hold‑down clamp.
Swap in new battery: Place the correct size (H5/47 or L1/063 on early cars). Ensure posts match orientation. Refit the clamp to spec.
Reconnect: Positive (+) first, then negative (−). Attach the vent tube to the battery’s vent port.
Initial check: Start the car, verify voltage (13.8–14.6V running), and ensure no battery/charging warnings.
Reset items: Set clock/windows if needed. Some start‑stop cars may relearn idle/charging after a short drive.
When to use a shop: If the car has start‑stop or you’re switching tech (EFB→AGM), many shops can code/register the battery and test the alternator/DC‑DC system.

Smart Car Battery Maintenance & Longevity

Drive pattern: Short, infrequent trips? Use an intelligent maintainer (AGM‑safe) to avoid sulfation.
Clean connections: Keep posts/clamps clean and tight; protect with dielectric grease.
Avoid deep discharges: Don’t leave lights or accessories on; AGM tolerates this better but still ages faster when deeply cycled.
Heat management: Park in shade when possible; heat is the #1 battery killer.
Annual test: Have a shop run a conductance test before winter or road trips.

Signs You Need a New Battery

Slow cranking, especially after overnight sits
Frequent start‑stop disable warnings (453)
Dashboard battery/charging alerts, dim lights at idle
12.2V or less at rest after full charge (ageing cell)
Swollen case, sulfur smell, or electrolyte stains

2-Pack Smart Fully Automatic 6V 12V Battery Charger Maintainer for Car, Marine, Motorcycle, Lawn Mower

$39.97

YONHAN Battery Charger 10-Amp 12V and 24V Fully-Automatic Smart Car Battery Charger, Battery Maintainer Trickle Charger, and Battery Desulfator with Temperature Compensation

$25.99

Tworider 12 pcs Battery terminal cleaner tool kit, battery brush, Wash Cleaning Battery Wire Brush Post Battery Cable Cleaner Dirt Corrosion Brushes Hand Tool Car Battery Cleaner Tool

$6.99

Contact Smart Customer Service & Support

smart USA resources: Support hub, Owner’s manuals, and service/dealer locator.
Worldwide smart: Choose your country at global.smart.com or find a showroom in the UK/EU via the dealer locator.
Official owner’s manual (453 example): 2016 fortwo Operator’s Manual (PDF).

Smart Car Battery FAQs

Can I upgrade from a standard flooded battery to AGM in my Smart?
Yes, in most Smart models AGM is considered an upgrade. AGM (Absorbent Glass Mat) batteries are sealed, vibration-resistant, recharge faster, and tolerate deep discharge better than basic flooded lead-acid. You can safely go from flooded → AGM without harming the charging system in most cases. What you should not do is go backward (AGM → basic flooded) if the car relies on stable voltage for all its electronics, especially in newer Smart models with start-stop or heavy accessory load.

Do I need a special battery for start-stop in my Smart?
If your Smart uses start-stop or “micro-hybrid” idle cutoff, you should use at least an EFB (Enhanced Flooded Battery) or AGM. Those chemistries are built for repeated engine restarts in traffic and frequent partial discharge. Installing a cheap standard flooded battery instead can shorten lifespan dramatically and can trigger electrical warnings or weak restarts at red lights.

How long should a Smart car battery last?
Most Smart car 12V batteries last around 3–4 years in typical city usage. Smarts are often driven on short trips with lots of accessories (lights, HVAC fan, infotainment) and very little sustained charging time, which is harder on the battery. With mostly highway miles, moderate climate, and an AGM/EFB battery that’s kept topped up, you can sometimes see 5 years or more. Extreme heat, long storage without a maintainer, and constant start-stop cycles can pull that down to about 2–3 years.

How much is a Smart car battery?
Expect roughly $120–$180 for a standard flooded or compact EFB-sized replacement in older Smart city cars, and about $180–$260 for a high-quality AGM with better reserve capacity and deeper cycle durability. Pricing at the dealer can run higher, especially if installation is included or if the Smart uses a specific case size that’s less common at big-box auto parts stores.

What size battery does my Smart need?
Smart cars often use a small case size with tight packaging. You need to match three things: physical footprint so it fits in the tray, terminal orientation so the cables reach without strain, and the factory Cold Cranking Amps (CCA) / Reserve Capacity (RC) rating. The easiest way to confirm is to read the label on your current battery or check the owner’s manual/parts catalog for your exact model year and engine type before you order.

When should I replace the battery instead of just recharging it?
Replace it if the car struggles to crank after sitting overnight, interior lights dim hard on startup, or you’re seeing random electrical glitches like radio resets, cluster warning lights that disappear after driving, or power steering assist cutting in and out. If voltage keeps sagging below ~12.4V at rest even after a long drive or a proper charger session, that battery is sulfated and it’s usually cheaper to replace than keep jump-starting it.

Does warranty matter when choosing a Smart battery?
Definitely. Look for a clear free-replacement window (often 24–36 months) rather than only pro-rated coverage. A stronger warranty usually signals thicker internal plates, better vibration resistance, and better cycle life under the stop-and-go abuse that Smart city cars see every day.

Bottom line: For most modern Smarts (451/453 and EQ/ED), a quality H5 / Group 47 battery is the correct footprint. If your car has start‑stop or you drive mostly short urban trips, choose AGM H5; otherwise EFB H5 is a great value. Early cars (450/452) typically use the smaller L1 / 063 size. Prioritize fresh stock, solid CCA (650 A class), high RC, and a 3+ year warranty. Use the fitment table and quick picks above to buy with confidence.

Best Car Battery for Smart – Top Picks for Every Model

ACDelco Gold 48AGM (88864541) 36 Month Warranty AGM BCI Group 48 Battery

Weize Platinum AGM Battery BCI Group 24F Automotive Battery, 120RC, 710CCA, 36 Months Warranty, Dimensions 10.75" L x 6.81" W x 8.98" H

$199.99

Weize Platinum AGM Battery BCI Group 47-12v 60ah H5 Size 47 Automotive Battery, 100RC, 680CCA, 36 Months Warranty, Dimensions 9.52" L x 6.89" W x 7.48" H