Can I install a higher capacity battery in my Caterham 21 1.8?

Yes, you can install a higher capacity (Ah) battery as long as the physical dimensions fit your Caterham 21 1.8 battery compartment and the positive terminal position matches.

What battery fits the Caterham 21 1.8?

The Caterham 21 1.8 requires a battery with the correct capacity (Ah) and Cold Cranking Amps (CCA) for this engine. Compatible batteries offer 24-30 Ah, 200-300 A (CCA), 12 V, case 12N24-4, conventional flooded technology. Browse the compatible battery list below.

How many Ah does the Caterham 21 1.8 battery need?

The exact Ah rating for the Caterham 21 1.8 depends on the vehicle's original electrical consumers. Compatible batteries offer 24-30 Ah, 200-300 A (CCA), 12 V, case 12N24-4, conventional flooded technology. Use our finder for a precise recommendation.

How long does a battery last in a Caterham 21 1.8?

With normal use, a battery for the Caterham 21 1.8 lasts 3–5 years. A healthy alternator and avoiding deep discharges significantly extend battery life.

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.

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Caterham 21 1.8

Batteries for Caterham 21 1.8 124 hp (petrol, 1997-2002)

Caterham · 21

Which battery does a Caterham 21 1.8 need?

Specifications and battery: 1.8 (124 hp)

Caterham 21 1.8 (124 hp, petrol, 1997-2002) takes a conventional 30 Ah, 300 A battery (186 × 130 × 171 mm).

Brand: Caterham
Model: 21 (C2)
Built: 04/1997 - 08/2002
Power: 91 kW / 124 hp
Fuel: Petrol
Engine size: 1,796 cc (1.8 L)
Cylinders: 4
Body type: Convertible
Drive: Rear-Wheel Drive
Engine codes: K 1.8

Battery for this engine

Version	Technology	Capacity	Cold cranking (EN)	Size (L×W×H)	Polarity
Main	Conventional	30 Ah	300 A	186 × 130 × 171 mm	—

The same batteries also fit the 1.6 i (117 hp), 1.6 i (133 hp), 1.6 i Supersport (140 hp), 1.8 (140 hp) and 6 more engines of this model.

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

🔧 Battery Expert Advisor

Battery analysis for your Caterham 21 1.8

Quick answer You need an ordinary lead-acid battery of 30 Ah. Our recommendation: VARTA YB30L-B. This vehicle may use more than one auxiliary battery size. Check the size fitted on your car before buying.

Batteries in your Caterham 21 1.8

Which battery do you want to replace?

MainOne optionSee all in the list →

Our recommendation

VARTA YB30L-B

ordinary lead-acid30 Ah300 A

186 × 130 × 171 mm

€186.30Buy

AuxiliaryOne optionSee all in the list →

Our recommendation

VARTA YB30L-B

ordinary lead-acid30 Ah300 A

186 × 130 × 171 mm

€186.30Buy

Prices and availability updated on 23/10/2026

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

📋 What we found

For your Caterham 21 1.8 we found 2 compatible auxiliary batteries.

⚡ Starter or auxiliary battery

We detected an auxiliary battery among the compatible ones. The auxiliary is NOT your main car battery: it is a smaller secondary battery that powers sensitive electronics. Don't mix them up when buying.

⭐ Our recommendation

Our recommendation

For your Caterham 21 1.8 we recommend the VARTA YB30L-B (ordinary lead-acid, 30 Ah). It also offers the highest capacity (Ah) and the highest cranking power (CCA) on the list — more headroom in cold starts and with many consumers. 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 Tuesday before 5 PM — your product ships on Monday.

See this battery →

Was this advisor helpful?

Verified selection

Class: Car Batteries
Brand: Caterham
Model: 21
Engine: 1.8

Order now with express shipping: your product ships on Monday and arrives on Tuesday 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.

Auxiliary Battery

Auxiliary battery for vehicles equipped with start-stop systems. It supports the main battery in functions such as engine start, the start-stop system, or additional electrical support.

2 products

Comparison table of available products
Category	Make	Reference	Capacity	Cold cranking	Dimensions	Price
Auxiliary Battery	VARTA	530034030	30 Ah	300 A	186×130×171 mm	€186.30	More info
Auxiliary Battery	VARTA	524101020	24 Ah	200 A	186×125×178 mm	€163.20	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 Caterham 21 1.8 battery compartment and the positive terminal position matches.
: The Caterham 21 1.8 requires a battery with the correct capacity (Ah) and Cold Cranking Amps (CCA) for this engine. Compatible batteries offer 24-30 Ah, 200-300 A (CCA), 12 V, case 12N24-4, conventional flooded technology. Browse the compatible battery list below.
: The exact Ah rating for the Caterham 21 1.8 depends on the vehicle's original electrical consumers. Compatible batteries offer 24-30 Ah, 200-300 A (CCA), 12 V, case 12N24-4, conventional flooded technology. Use our finder for a precise recommendation.
: With normal use, a battery for the Caterham 21 1.8 lasts 3–5 years. A healthy alternator and avoiding deep discharges significantly extend battery life.
: 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 Caterham 21 1.8 124 hp (petrol, 1997-2002)

Which battery does a Caterham 21 1.8 need?