Optima BTDC-5.0 · Marine battery 12V 66Ah 765A AGM
Specifications
| Brand | OPTIMA |
|---|---|
| Part number | BTDC-5.0 |
| Voltage (V) | 12 |
| Capacity (C20) | 66Ah (c20) |
| Capacity (C5) | 61Ah (c5) |
| Technology | AGM ESPIRAL |
| Length | 309.00 mm |
| Width | 172.00 mm |
| Height | 200.00 mm |
€225.70
VAT included
4,80/5★★★★★35 reviewsVerified purchases
- ★★★★★Cesar Nieto:
Excelente atención telefònico, recomiendo llamar a su número antes de comprar en otra web
- ★★★★★Iker Hernandez:
Web muy recomendable. En otras páginas ni cogen el teléfono.
- ★★★★★Rafael Soto:
Me ayudaron a elegir mi batería y, además, me ayudaron en la instalación
Optima BTDC-5.0 12V 66Ah 765A is a marine battery with reinforced anti-vibration case for moorings and offshore use. Tolerates the typical daily cycles on a boat (engine start + night-time services such as lights, sonar, fridge) and holds voltage even when the hull is rolling in open sea.
Why this marine battery?
- Marine designbuilt for boat swell and vibration
- Dual functionstarts the engine and powers onboard services
- Sealed and safemaintenance-free even when the boat rolls
Voltage
12 V
Capacity
66 Ah
Cold cranking
765 A
Dimensions
309×172×221 mm
Technology
AGM ESPIRAL
Polarity
Positive on the left
Weight
24,4 kg
Model
OPTIMA BLUE TOP
Marine battery Optima BTDC-5.0 Blue Top 66Ah 845A 12V
12VVoltage
66AhCapacity
845ACold cranking
22.70kgWeight
With 66 Ah at 12 V and 845 A of cold cranking current (EN), the Optima BTDC-5.0 from the Blue Top range is built for motor and sailing boats, both for engine starting and onboard services. Measuring 309 × 172 × 200 mm and the positive terminal on the left, it is the direct replacement for boats fitted from the factory with a 66 Ah battery of this format.
- Sealed: no spills or gases in the locker.
- Resistant to humidity and salt air.
- Spiral AGM construction, sealed and mountable in any position.
- Ready for starting outboard and inboard engines.
What the Optima BTDC-5.0 is for
With 66 Ah, the Optima BTDC-5.0 covers motor and sailing boats, both for engine starting and onboard services. At the end of the season, charge it fully before winter storage. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 22.70 kg and 1 & 21 terminals.
The Optima BTDC-5.0: Blue Top range and spiral-cell AGM technology
Within the Optima catalogue, the Blue Top series groups the references designed for this use. The BTDC-5.0 is the 66 Ah model of that family, with the same performance as its siblings in other sizes.
In a spiral-cell battery the electrolyte is absorbed and the plates are wound under pressure. That lets it deliver very high current peaks, recharge quickly and be mounted in any position.
Size, terminals and hold-down of the Optima BTDC-5.0
In terms of format, the Optima BTDC-5.0 measures 309 × 172 × 200 mm (length × width × height) and weighs 22.70 kg. The positive terminal on the left decides which side the cables end up on: it is the detail that causes most buying mistakes, so check it before ordering. It uses 1 & 21 terminals, the system that anchors and connects it in the vehicle. Checking the three dimensions and the terminal position before buying avoids the most common mistake when replacing a battery.
Optima: the maker behind the BTDC-5.0
The Optima Red, Yellow and Blue Top are references for high-performance starting, deep cycling and marine use respectively, all with the characteristic six spiral-cell design. All the Optima batteries in our catalogue are genuine product, recently manufactured and covered by the manufacturer's warranty.
Usage and maintenance tips
At the end of the season, charge the battery fully and, if possible, keep it on a charger over the winter lay-up. Protect the terminals with dielectric grease and check the fixing: vibration and swell loosen connections.
Warranty and coverage
The Optima BTDC-5.0 comes with the manufacturer's official warranty against manufacturing defects. Deep discharge from winter lay-up without charging is not covered.
When you get it and how to return it
Orders placed before 6:00 pm with the battery in stock ship the same day. Delivery in mainland Spain and Portugal takes 24-48 working hours; for the Balearic and Canary Islands and the rest of the European Union allow 3 to 5 working days. You have 14 days to return an unused battery; in mainland Spain and Portugal collection is free. We email you the tracking number as soon as the parcel ships.
BCOM-OPTIMA-BTDC-5.0
Data sheet
- Brand
- OPTIMA
- Reference
- BTDC-5.0
- Model
- OPTIMA BLUE TOP
- Voltage (V)
- 12
- Length
- 309.00 mm
- Width
- 172.00 mm
- Height
- 200.00 mm
- Weight
- 22.7 Kgs
- Technology
- AGM ESPIRAL
- EAN
- 4016987130346
- Terminal layout
- Positive terminal on the left
- Terminal type
- 1 & 21
- Cold cranking amps (EN)
- 845A
- Capacity (C20)
- 66Ah (c20)
- Capacity (C5)
- 61Ah (c5)
- ETN
- 8272270008882
Specific References
- EAN13
- 4016987130346
- MPN
- BTDC-5.0
4,80/5
Verified purchasesLatest verified reviews
★★★★★Cesar Nieto
16/07/2026Lo mejor, la atención al cliente
Excelente atención telefònico, recomiendo llamar a su número antes de comprar en otra web
★★★★★Iker Hernandez
04/06/2026Recomendable
Web muy recomendable. En otras páginas ni cogen el teléfono.
★★★★★Rafael Soto
10/04/2026Gracias por la ayuda
Me ayudaron a elegir mi batería y, además, me ayudaron en la instalación
★★★★★Pablo Aguilar
18/02/2026Perfecto
Recomiendo esta web, excelente servicio
★★★★★Roberto Romero
13/02/2026No tardó nada
Ya les había comprado una batería de moto, Ahora he pedido una de coche y me han asesorado super bien.
★★★★★Jose Francisco Gallego
11/02/2026Buenos profesionales, gracias por su ayuda
Tenía muchas dudas sobre la instalación y me guiaron paso a paso. Atención inmejorable.
★★★★★Jose Antonio Mora
25/01/2026Sobresaliente
Resolvieron todas mis dudas
★★★★★Juan Antonio Castro
10/01/2026La batería llegó a tiempo
Cumplen con el tiempo de entrega
★★★★★Ismael Gil
01/01/2026Me encantan
Recomiendo la web por su trato al momento de elegir
Codes and references Optima BTDC-5.0
| Brand | Optima · see all batteries Optima |
|---|---|
| Manufacturer range | OPTIMA BLUE TOP |
| Manufacturer reference (MPN) | BTDC-5.0 |
| ETN code | 8272270008882 (short form 827 227 000) |
| EAN-13 barcode | 4016987130346 |
| Dimensions (length × width × height) | 309 × 172 × 221 mm (309x172x221) |
Recommended accessories
How to change the battery
Guide to replace a marine battery (cranking or house) in 20-30 minutes. Moisture and vibration in marine environments require reinforced hold-downs and sealed copper terminals.
Step 1. Prepare the vehicle
Park on a flat surface, switch off the engine and remove the key. Make sure all lights and electrical accessories are off. Wait 1-2 minutes before starting.
Step 2. Locate the battery compartment
Usually under the passenger bench, engine room or a dedicated ventilated compartment. Verify the compartment is dry and well ventilated before opening.
Step 3. Disconnect the negative (−) terminal
Use the 10 mm wrench to loosen the negative cable nut (black, marked −) and remove the cable from the post. Move it aside so it cannot touch any bodywork.
Step 4. Disconnect the positive (+) terminal
Repeat with the positive cable (red, marked +). Important: never let a terminal touch metal of the car while the other is still connected.
Step 5. Remove the old battery
Marine batteries are heavy (15-50 kg). If it has rope handles, use them; otherwise have a carry strap ready. Secure the new one with metal hold-downs (not plastic) to resist sea-state vibration.
Step 6. Install the new battery
Place the battery in the same orientation as the old one (positive terminal on the same side). Tighten the hold-down clamp firmly.
Step 7. Connect the cables
Connect the positive (+) terminal first, then the negative (−). Tighten the nuts with the wrench until each terminal does not move. Apply anti-spark grease if you have any.
Step 8. Verify circuit + water protection
Apply dielectric grease on terminals to prevent salt-air corrosion. Check the engine charging circuit delivers 13.8-14.4 V at 2,000 rpm.
Frequently asked questions
Is the Optima BTDC-5.0 an AGM battery and what are the benefits of AGM?
Yes. The BTDC-5.0 from Optima uses AGM (Absorbent Glass Mat) technology: a sealed lead-acid battery where the electrolyte is absorbed in a glass-fibre mat. It withstands more charge/discharge cycles than a conventional one, handles heat better and is the required technology for boats with advanced Start-Stop and regenerative braking. Expected lifespan: 5-8 years under normal conditions.
How do I fit the BTDC-5.0 model in my boat?
In most boats it fits in 15-30 minutes with a 10 mm wrench; if the battery is under the seat or in the boot the time can double. See the step-by-step guide on this page. Quick summary: 1) switch off the engine and remove the key; 2) locate the original battery (engine bay, boot or under seat); 3) disconnect the negative (−) terminal first, then the positive (+); 4) loosen the hold-down clamp and remove the old battery; 5) fit the new one in the same orientation — match the polarity shown on the product sheet; 6) connect the positive (+) first, then the negative (−). On boats with Start-Stop or BMS, register the battery via OBD so the alternator applies the correct charging profile.
How long does the Optima BTDC-5.0 battery last?
Expected lifespan of the Optima BTDC-5.0 is 5 to 8 years in mild-climate boat use with Start-Stop. In cold regions it drops slightly due to cold-start stress; in very hot regions it also drops because of electrolyte evaporation. To extend its life: avoid deep discharges (headlights on with engine off), have the alternator checked yearly, and keep the battery clean and properly secured.
What are the dimensions of the Optima BTDC-5.0 battery?
Dimensions (length × width × height) are 309×172×221 mm — also written as 309x172x221 mm — following the European DIN standard. Always measure the space in your boat before buying: even one extra millimetre can prevent the hold-down clamp from closing. The height shown includes the terminals.
What ETN and EAN codes does the Optima BTDC-5.0 battery have?
The manufacturer reference (MPN) is BTDC-5.0 and its ETN code is 8272270008882 (short form 827 227 000), the European identifier used in spare-part catalogues. The EAN-13 barcode is 4016987130346. It belongs to the OPTIMA BLUE TOP range. Any of these codes identifies exactly this battery when requesting quotes or comparing prices.
Is the BTDC-5.0 valid for my vehicle?
Three options to confirm: 1) enter your number plate in the finder (DGT/DVLA/KBA auto-detect your model and engine); 2) check the "Compatible vehicles" tab on this page, where we list every vehicle verified by our technical team; 3) if you cannot find your model, message us on WhatsApp with brand, model, engine and year — we reply during business hours (Mon–Fri 10:00–13:30 and 16:40–18:00 (Spanish time, CET)). The BTDC-5.0 typically fits a wide range of European vehicles thanks to its standard DIN case format.
What are the equivalents of the BTDC-5.0 model?
Directly interchangeable batteries (same dimensions, same polarity, same Ah and CCA) are the OEM equivalents from leading brands: Bosch, Tudor, Exide and, depending on the model, Banner or Yuasa. Exact equivalence depends on technology — an EFB cannot be replaced with a conventional battery in Start-Stop boats. See the "Equivalents" section to view recommended options at the same performance level.
The top-rated online battery store in Spain
-
Audited by Trustpilot, no filters, no edits. The top-rated battery store in Spain.
Trustpilot · verified, no filters
-
Official Varta distributor
Official Varta wholesale distributor. 100% genuine batteries, recently manufactured, best price and no middlemen.
World’s best-selling battery brand
-
+100,000 satisfied customers
More than 100,000 customers already trust baterias.com — and recommend us to their friends and family.
They trust us and recommend us
Choose trust, choose quality, choose baterias.com.