Can I install a higher capacity battery in my Subaru REX III 0.5?

Yes, you can install a higher capacity (Ah) battery as long as the physical dimensions fit your Subaru REX III 0.5 battery compartment and the positive terminal position matches.

What battery fits the Subaru Rex III 0.5?

The Subaru Rex III 0.5 requires a battery with the correct capacity (Ah) and Cold Cranking Amps (CCA) for this engine. Compatible batteries offer 45 Ah, 330 A (CCA), 12 V, case B24, conventional flooded technology. Browse the compatible battery list below.

How many Ah does the Subaru Rex III 0.5 battery need?

The exact Ah rating for the Subaru Rex III 0.5 depends on the vehicle's original electrical consumers. Compatible batteries offer 45 Ah, 330 A (CCA), 12 V, case B24, conventional flooded technology. Use our finder for a precise recommendation.

What type of battery does my car need?

You need the make, model and engine. If your car has Start-Stop (the engine switches off at traffic lights), it needs an EFB or an AGM battery, depending on what it came with: if it has an AGM, fit another AGM; if it has an EFB, another EFB or an AGM. On cars with battery management (BMW, Mercedes, VAG group…), moving from EFB to AGM requires coding the new battery. Without Start-Stop, a conventional battery is fine, or an EFB or AGM if you want a longer life.

What is the difference between AGM, EFB and standard batteries?

A conventional (lead-acid) battery is for cars without Start-Stop. An EFB is a reinforced conventional battery for basic Start-Stop. An AGM offers the highest performance and is fitted as standard on cars with advanced Start-Stop, regenerative braking or high electrical demand. Replacement rule: an AGM only with another AGM; an EFB with another EFB or an AGM; a conventional battery with any of the three. Never move down in technology.

How do I find the right battery for my vehicle?

Use the search tool by selecting your vehicle's make and model. Our system automatically filters compatible part numbers verified by our technicians. If you have any questions, contact us via WhatsApp.

What warranty do the batteries have?

All our batteries come with the legal guarantee provided by consumer law against manufacturing defects. If a battery has a manufacturing defect, it will be replaced at no cost to the user.

How long does it take for the battery to arrive?

Under normal circumstances, batteries usually arrive within 1 to 2 days of ordering. However, there are some cases where delivery may take a little longer: peak seasons (Black Friday, Christmas, etc.), palletized shipments, occasional stock shortages, etc.

12,287 customer reviewsThank you for trusting us!Thank you! Excellent 4.5 out of 5

Subaru REX III 0.5

Batteries for Subaru REX III 0.5 38 hp (petrol, 1989-1990)

Subaru · REX III

Which battery does a Subaru REX III 0.5 need?

Specifications and battery: 0.5 (38 hp)

Subaru REX III 0.5 (38 hp, petrol, 1989-1990) takes a conventional 45 Ah, 330 A battery (238 × 129 × 227 mm), with the positive terminal on the right. (EN05)

Recommended battery for this engine Car battery Varta B31 12V 45Ah 330A €47.60 incl. VAT

View battery →

Brand: Subaru
Model: REX III
Built: 06/1989 - 07/1990
Power: 28 kW / 38 hp
Fuel: Petrol
Engine size: 547 cc (0.5 L)
Cylinders: 4
Body type: Hatchback
Drive: Front-Wheel Drive
Engine codes: EN05

Battery for this engine

Version	Technology	Capacity	Cold cranking (EN)	Size (L×W×H)	Polarity
Main	Conventional	45 Ah	330 A	238 × 129 × 227 mm	+ on the right

This engine shares its battery with the 0.5 4WD (38 hp), 0.5 Kompressor (61 hp), 0.7 (64 hp), 0.7 (48 hp) and 3 more: the compatible batteries are exactly the same.

Data: vehicle specifications and the battery manufacturer's application catalogue.

EFB, AGM or conventional for this engine?

Rule of thumb for the Subaru REX III 0.5: fit the same technology as the original or better (conventional → EFB → AGM), with equal or higher capacity and cold cranking amps, and respect the size and terminal position of around 45 Ah.

🔧 Battery Expert Advisor

Battery analysis for your Subaru REX III 0.5

Quick answer You need an ordinary lead-acid battery of 45 Ah. Our recommendation: VARTA B31.

VARTAB31

ordinary lead-acid45 Ah330 A238×129×227

€47.60

Buy

Prices and availability updated on 30/10/2026

Based on the batteries we found for your vehicle, our experts help you pick the right one.

📋 What we found

For your Subaru REX III 0.5 we found 3 compatible conventional (non Start-Stop) batteries.

⚡ Battery type for your vehicle

✓ Your Subaru REX III 0.5 does not need a Start-Stop battery. The conventional ones shown fit your vehicle and are the most affordable option. If you want a higher-quality, longer-lasting battery, you can also fit an EFB or AGM as an upgrade — they are fully compatible and last more years.

📊 View AGM vs EFB vs Conventional — full comparison

⭐ Our recommendation

Our recommendation

For your Subaru REX III 0.5 we recommend the VARTA B31 (ordinary lead-acid, 45 Ah). It's the battery recommended by the vehicle manufacturer for your Subaru REX III 0.5 — the OEM equivalent. Varta is the world's leading manufacturer of starter batteries and supplies first-equipment (OEM) batteries to the major European car makers.

Get it on Monday before 5 PM — your product ships today.
The best value price among compatible options.

See this battery →

Was this advisor helpful?

Verified selection

Class: Car Batteries
Brand: Subaru
Model: REX III
Engine: 0.5

Order now with express shipping: your product ships today and arrives on Monday before 5 PM (Spain mainland and Portugal only).

Before you buy: check 3 key points

Although the batteries shown are sourced from information provided by manufacturers, we recommend checking on your current battery:

Dimensions (length × width × height, including terminals and protrusions)
The dimensions shown are the maximum of the battery and include the height of the terminals, small ridges at the base and any lateral protrusions. Measure your current battery completely, from edge to edge. The new one must be the same size or slightly smaller — never larger, it would not fit in the housing.
Positive terminal (left or right viewed from the front — check the battery photo carefully)
Stand facing the battery, with the manufacturer's label facing you and the terminals on top. Locate the terminal marked with +: if it is on your right, it is "positive right"; if it is on your left, it is "positive left". Do not rely on how the battery is mounted in the car — the position is always measured looking only at the battery itself.
Technology (AGM, EFB or conventional — the same as your current battery or higher)
Depending on the manufacturer, the same technology may be labelled differently: AGM may also appear as VRLA, AGM Start-Stop or AGM Deep Cycle. EFB may appear as EF, EFB+ or Enhanced Flooded Battery. Conventional may appear as SLI, Lead-Acid, Wet or Standard. If your vehicle has Start-Stop, the battery must be AGM or EFB — never conventional.

If you have any questions, just ask us and we'll be glad to advise you with no obligation.

Conventional Battery

This is a standard or conventional battery for vehicles without a start-stop system

3 products

Comparison table of available products
Category	Make	Reference	Capacity	Cold cranking	Dimensions	Technology	Price
Conventional Battery	VARTA	B31	45 Ah	330 A	238×129×227 mm	Conventional	€47.60	More info
Conventional Battery	TUDOR	TB456	45 Ah	330 A	237×127×227 mm	Conventional	€71.90	More info
Conventional Battery	EXIDE	EB456	45 Ah	330 A	237×127×227 mm	Conventional	€83.20	More info

Complete your purchase

Chargers

Chargers for your battery

1 product

Battery charger ABSAAR Pro4.0 6/12V 4A Smart Charger
- 6 V
€50.60

Frequently asked questions

: Yes, you can install a higher capacity (Ah) battery as long as the physical dimensions fit your Subaru REX III 0.5 battery compartment and the positive terminal position matches.
: The Subaru Rex III 0.5 requires a battery with the correct capacity (Ah) and Cold Cranking Amps (CCA) for this engine. Compatible batteries offer 45 Ah, 330 A (CCA), 12 V, case B24, conventional flooded technology. Browse the compatible battery list below.
: The exact Ah rating for the Subaru Rex III 0.5 depends on the vehicle's original electrical consumers. Compatible batteries offer 45 Ah, 330 A (CCA), 12 V, case B24, conventional flooded technology. Use our finder for a precise recommendation.
: You need the make, model and engine. If your car has Start-Stop (the engine switches off at traffic lights), it needs an EFB or an AGM battery, depending on what it came with: if it has an AGM, fit another AGM; if it has an EFB, another EFB or an AGM. On cars with battery management (BMW, Mercedes, VAG group…), moving from EFB to AGM requires coding the new battery. Without Start-Stop, a conventional battery is fine, or an EFB or AGM if you want a longer life.
: A conventional (lead-acid) battery is for cars without Start-Stop. An EFB is a reinforced conventional battery for basic Start-Stop. An AGM offers the highest performance and is fitted as standard on cars with advanced Start-Stop, regenerative braking or high electrical demand. Replacement rule: an AGM only with another AGM; an EFB with another EFB or an AGM; a conventional battery with any of the three. Never move down in technology.
: Use the search tool by selecting your vehicle's make and model. Our system automatically filters compatible part numbers verified by our technicians. If you have any questions, contact us via WhatsApp.
: All our batteries come with the legal guarantee provided by consumer law against manufacturing defects. If a battery has a manufacturing defect, it will be replaced at no cost to the user.
: Under normal circumstances, batteries usually arrive within 1 to 2 days of ordering. However, there are some cases where delivery may take a little longer: peak seasons (Black Friday, Christmas, etc.), palletized shipments, occasional stock shortages, etc.
: In mainland Spain delivery takes 24-48 working hours if you order before 6:00 pm (Monday to Friday) and the battery is in stock; mainland Portugal takes 1 to 4 working days, the Balearic Islands 2 to 5 working days and other EU destinations 4 to 7 working days. Batteries are shipped fully charged and ready to install.

Guides

: This vehicle has no Start-Stop. According to the manufacturer, it does not need to be registered after the change.

Batteries for Subaru REX III 0.5 38 hp (petrol, 1989-1990)

Which battery does a Subaru REX III 0.5 need?