Tudor TZ850 · Marine battery 12V 100Ah 900A EFB

Marine battery EFB Tudor TZ850 12V 100Ah 900A - 1
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  • Marine battery EFB Tudor TZ850 12V 100Ah 900A - 1

Specifications

BrandTUDOR
Part numberTZ850
Capacity (C20)100Ah (c20)
Cold cranking amps (EN)900A
TechnologyEFB
Length353mm
Width175mm
Height190mm
Weight25.50 Kg
See the full specifications →
€146.20
VAT included
Quantity

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Brand: TUDOR Part number: TZ850

Tudor TZ850 100Ah 900A 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
Capacity
100 Ah C20
Cold cranking
900 A EN-1
Dimensions
353×175×190 mm
Technology
EFB
Polarity
Positive on the right
Weight
25,5 kg

Marine battery Tudor TZ850 100Ah 900A 12V

12VVoltage
100AhCapacity
900ACold cranking
25.50kgWeight

The Tudor TZ850 with EFB technology is a marine battery with 100 Ah and 900 A of cold cranking current (EN) for motor and sailing boats, both for engine starting and onboard services. Its 353 × 175 × 190 mm and the positive terminal on the right make it the exact replacement for the 100 Ah battery fitted as standard to many boats.

  • Resistant to humidity and salt air.
  • Sealed: no spills or gases in the locker.
  • Ready for starting outboard and inboard engines.
  • EFB: the evolution of the conventional battery for basic Start-Stop cars.

What the Tudor TZ850 is for

On board, the Tudor TZ850 provides 100 Ah with a case reinforced against vibration and swell. Keep the terminals clean and protected from salt humidity. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 25.50 kg, EN taper post terminals and B13 hold-down.

Technology inside the Tudor TZ850

The TZ850 is one of the Tudor references for this type of use; it shares the same manufacturing and quality-control criteria as the rest of the brand's catalogue.

EFB (Enhanced Flooded Battery) technology reinforces the conventional lead-acid battery with a polyester separator and carbon additives in the plates. It withstands many more start cycles and partial discharges, making it ideal for basic Start-Stop and intensive use.

Size, terminals and hold-down of the Tudor TZ850

The Tudor TZ850 is made in the 353 × 175 × 190 mm format and weighs 25.50 kg. The positive terminal on the right decides which side the cables end up on: it is the detail that causes most buying mistakes, so check it before ordering. It uses a B13 hold-down and EN taper post terminals, the system that anchors and connects it in the vehicle. For a direct replacement, the current battery tray must accept these dimensions and the same terminal layout; otherwise adapters will be needed or the hold-down will change.

Why choose Tudor batteries

Tudor is Spain's historic battery brand, today part of the Exide group. Its car, truck, motorcycle and leisure ranges are built with the same technology and controls as the group's original-equipment references. All the Tudor batteries in our catalogue are genuine product, recently manufactured and covered by the manufacturer's warranty.

Usage and maintenance tips

A charger with an EFB or smart conventional mode is enough; avoid the high-voltage modes intended for AGM. At the end of the season, charge the battery fully and, if possible, keep it on a charger over the winter lay-up.

Warranty and coverage

The Tudor TZ850 comes with the manufacturer's official warranty against manufacturing defects. Deep discharge from winter lay-up without charging is not covered.

Delivery times and returns

Order before 6:00 pm with stock available and it leaves today: mainland Spain and Portugal receive it in 24-48 working hours, the islands and the rest of the EU in 3 to 5 days. You have 14 days to return it if it has not been installed, with free collection on the mainland, and shipment tracking by email.

BCOM-TUDOR-TZ850

Data sheet

Voltage (V)
Length
353mm
Width
175mm
Height
190mm
Weight
25.50 Kg
Technology
EFB
EAN
3661024057608
Terminal layout
Positive right
Terminal type
EN taper post
Hold-down
B13
Cold cranking amps (EN)
900A
Capacity (C20)
100Ah (c20)

Specific References

EAN13
3661024057608
MPN
TZ850

Codes and references Tudor TZ850

Brand Tudor · see all Tudor batteries
Manufacturer reference (MPN) TZ850
EAN-13 barcode 3661024057608
European case size (EN 50342-2) L5
Dimensions (length × width × height) 353 × 175 × 190 mm (353x175x190)

Comparison: Tudor TZ850 vs equivalents — alternatives with the same dimensions, Ah and CCA

The Tudor TZ850 is interchangeable with these equivalent references: LFD90 (Varta).

Product Specifications Technology Price
Tudor TZ850 Tudor TZ850 This battery €146.20
Varta LFD90 Varta LFD90 ★ 4,8 12V 90Ah 800A Lead-acid €215.30

Equivalences verified by our technical team: same dimensions, polarity, capacity and CCA. Official manufacturer warranty on every option.

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.

⏱ 20-30 min🛠 Tools: 10 mm or 13 mm wrench (depending on terminal) · Protective gloves
  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

How is the Tudor TZ850 battery installed in the vehicle?

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 many years does this battery last?

Expected lifespan of the Tudor TZ850 is 4 to 7 years in regular use (depends on technology and climate). 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 Tudor TZ850 battery?

Dimensions (length × width × height) are 353×175×190 mm — also written as 353x175x190 mm and correspond to the European L5 case size — 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.

Will the Tudor TZ850 battery fit my boat?

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 TZ850 typically fits a wide range of European vehicles thanks to its standard DIN case format.

Which batteries are equivalent to the Tudor TZ850?

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.


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