What battery does the REX RS RS 900 use?

REX RS RS 900 (3 hp, petrol, from 2007) takes a 8 Ah, 105 A AGM battery (150 × 87 × 93 mm), with the positive terminal on the left. We found 6 compatible batteries priced between 22,90€ — 48,20€. Check dimensions and positive terminal position before purchasing.

Can I install a higher capacity battery in my REX RS RS 900?

Yes, you can install a higher capacity (Ah) battery as long as the physical dimensions fit your REX RS RS 900 battery compartment and the positive terminal position matches.

Does my REX RS RS 900 need a Start-Stop battery?

Yes, we detected Start-Stop compatible batteries for your REX RS RS 900. If your vehicle has Start-Stop, it needs an AGM or EFB battery. An AGM must always be replaced with AGM. An EFB can be replaced with EFB or AGM. Never install a conventional battery in a Start-Stop vehicle.

What type of battery does my motorcycle need?

Motorcycles can use GEL, AGM, or conventional batteries. GEL batteries are ideal for occasional use. AGM batteries are the best option for heavy use or high-power motorcycles. Always check the polarity before installation.

How do I know the polarity of my motorcycle battery?

Polarity indicates which side has the positive (+) terminal. This is critical for motorcycles because some models have the positive terminal on the left and others on the right. Check the label on your current battery or the manufacturer's manual.

Can I install my motorcycle battery myself?

Yes. First disconnect the negative (−) wire and then the positive (+) wire. When installing the new one, connect the positive (+) wire first and then the negative (−) wire. Always respect the correct polarity.

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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REX RS RS 900

Batteries for REX RS RS 900 3 hp (petrol, from 2007)

REX · RS

Which battery does a REX RS RS 900 need?

Specifications and battery: RS 900 (3 hp)

REX RS RS 900 (3 hp, petrol, from 2007) takes a 8 Ah, 105 A AGM battery (150 × 87 × 93 mm), with the positive terminal on the left.

Brand: REX
Model: RS
Built: 2007 - 2026
Fuel: Petrol
Cylinders: 1
Drive: Vario

Battery for this engine

Version	Technology	Capacity	Cold cranking (EN)	Size (L×W×H)	Polarity
Main	AGM	8 Ah	105 A	150 × 87 × 93 mm	+ on the left

The same batteries also fit the RS 1000 (8 hp), RS 1100 (8 hp), RS 125 (7 hp), RS 400 (4 hp) and 4 more engines of this model.

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

🔧 Battery Expert Advisor

Battery analysis for your REX RS RS 900

Quick answer You need an AGM battery of 8 Ah. Our recommendation: VARTA 508901015.

VARTA508901015

AGM8 Ah105 A150×87×93

€39.10

Buy

Prices and availability updated on 20/10/2026

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

📋 What we found

For your REX RS RS 900 we found 6 compatible Start-Stop batteries.

📏 Battery size

The list contains batteries in different sizes or capacities (Ah). In many cases both variants fit, but it's worth checking your compartment dimensions and the Ah of your original battery before buying. Choose the one with the same dimensions as your current battery: a bigger one may not fit the compartment or the hold-down. If several match your size, the higher capacity gives more headroom for cold starts.

⚡ Battery type for your vehicle

✓ Your REX RS RS 900 uses the Start-Stop system. Every battery shown is compatible — no conventional options to confuse you.

🔋 Technology (AGM / EFB)

✓ All Start-Stop batteries in the list are AGM — the most advanced technology. Perfect if your current battery was AGM or EFB: AGM always replaces both. Remember to register it via OBD if your car has a BMS (BMW, Audi, VAG, Mercedes…) so the alternator charges it correctly.

📊 View AGM vs EFB vs Conventional — full comparison

⭐ Our recommendation

Our recommendation

For your REX RS RS 900 we recommend the VARTA 508901015 (AGM, 8 Ah). It also delivers the most cranking power (CCA) on the list — a clear edge in cold starts. Varta is the world's leading manufacturer of starter batteries and supplies first-equipment (OEM) batteries to the major European car makers.

Next-day delivery if you order before 6 PM.
19% cheaper than the most expensive option in the list.

See this battery →

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Verified selection

Class: Motorcycle Batteries
Brand: REX
Model: RS
Engine: RS 900

Receive them tomorrow before 2 PM if you order before 6 PM (Spain mainland and Portugal only).

Before you buy: check the JIS code on your battery

On motorcycles, the definitive identifier is the JIS (Japanese Industrial Standard) code printed on the original battery — for example YT12B-BS, YTX9-BS or YB12AL-A2. It identifies the model 100%: dimensions, capacity, polarity and terminal type.

Make sure the JIS code of the battery you are buying matches the one on your current battery
How to find the JIS code on your battery: it is printed on the manufacturer's label, usually on the top or front face of the battery, next to the voltage and capacity. It typically starts with Y (Yuasa) followed by letters and numbers: YT, YTX, YTZ, YB, YT-BS, etc. Some brands use parallel equivalents (FT, GT, BT, EB) — all follow the JIS standard. If the code of the battery you are buying matches yours (same letters and numbers before the «-BS» / «-A2»), it is the correct battery. If it differs even by a single digit, the dimensions or capacity do not match and it will NOT fit.

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

Start-Stop & high energy demand batteries

AGM or EFB battery for start-stop vehicles and for cars with high energy demand (many electrical consumers, frequent starts). More charge cycles, better charge recovery and longer service life.

6 products

This engine comes with an AGM/EFB battery as standard: the car's charging system requires it even without Start-Stop. If in doubt, message us and we will confirm.

Why we recommend the VARTA 508901015

For €16.20 more you get +60 A cold cranking and +2 Ah capacity.

	RecommendedVARTA 508901015	CheapestEXIDE ETX7A-BS
Cold cranking	150 A	90 A
Capacity	8 Ah	6 Ah
Technology	AGM	AGM
Why	Varta brand	—
Price	€39.10	€22.90

View VARTA 508901015

Comparison table of available products
Category	Make	Reference	Capacity	Cold cranking	Dimensions	Technology	Price
Start-Stop & high energy demand batteries	VARTA	508901015	8 Ah	150 A	150×87×93 mm	AGM	€39.10	More info
Start-Stop & high energy demand batteries	EXIDE	ETX7A-BS	6 Ah	90 A	150×90×95 mm	AGM	€22.90	More info
Start-Stop & high energy demand batteries	VARTA	506015011	6 Ah	105 A	151×88×94 mm	AGM	€33.30	More info
Start-Stop & high energy demand batteries	EXIDE	ETZ10-BS	9 Ah	145 A	150×90×95 mm	AGM	€34.10	More info
Start-Stop & high energy demand batteries	EXIDE	AGM12-8	8.60 Ah	145 A	150×90×95 mm	AGM	€48.20	More info
Start-Stop & high energy demand batteries	EXIDE	AGM12-6	6 Ah	90 A	150×90×95 mm	AGM	€46.70	More info

Frequently asked questions

: REX RS RS 900 (3 hp, petrol, from 2007) takes a 8 Ah, 105 A AGM battery (150 × 87 × 93 mm), with the positive terminal on the left. We found 6 compatible batteries priced between 22,90€ — 48,20€. Check dimensions and positive terminal position before purchasing.
: Yes, you can install a higher capacity (Ah) battery as long as the physical dimensions fit your REX RS RS 900 battery compartment and the positive terminal position matches.
: Yes, we detected Start-Stop compatible batteries for your REX RS RS 900. If your vehicle has Start-Stop, it needs an AGM or EFB battery. An AGM must always be replaced with AGM. An EFB can be replaced with EFB or AGM. Never install a conventional battery in a Start-Stop vehicle.
: Motorcycles can use GEL, AGM, or conventional batteries. GEL batteries are ideal for occasional use. AGM batteries are the best option for heavy use or high-power motorcycles. Always check the polarity before installation.
: Polarity indicates which side has the positive (+) terminal. This is critical for motorcycles because some models have the positive terminal on the left and others on the right. Check the label on your current battery or the manufacturer's manual.
: Yes. First disconnect the negative (−) wire and then the positive (+) wire. When installing the new one, connect the positive (+) wire first and then the negative (−) wire. Always respect the correct polarity.
: 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.

Guides

Batteries for REX RS RS 900 3 hp (petrol, from 2007)

Which battery does a REX RS RS 900 need?