# Stationary UPS battery Fulbat FP4-3.5 4V 3.5Ah AGM

![Stationary UPS battery Fulbat FP4-3.5 4V 3.5Ah AGM](https://baterias.com/6316-home_default/battery-fulbat-fp4-3-5-4v-3-5ah.jpg)

> Fulbat FP4-3.5 stationary UPS battery 4V 3.5Ah AGM. FP General Purpose range. Dimensions 90×34×65 mm, + terminal on the left. Long float life.

**Category:** [Batteries for UPS / UPS](https://baterias.com/gb/batteries-for-sai-ups) → [FULBAT](https://baterias.com/gb/fulbat)

- **Canonical URL**: https://baterias.com/gb/battery-fulbat-fp4-3-5-4v-3-5ah
- **Language**: en-GB
- **Brand**: FULBAT
- **Reference**: BCOM-FULBAT-FP4-3.5
- **MPN**: FP4-3.5
- **Stock**: Out of stock

## Technical specifications

| Feature | Value |
|---|---|
| Brand | FULBAT |
| Model | FULBAT FP General Purpose |
| Voltage (V) | 4 V |
| Largo | 90 mm |
| Ancho | 34 mm |
| Alto | 65 mm |
| Tecnología | AGM |
| Terminal layout | Positive left |
| Terminal type | FASTON-4.8 |
| Capacity (C20) | 3.5 Ah |

## Quick description

**Fulbat FP4-3.5 4V 3,5Ah** is a stationary battery for backup power systems: UPS, alarms, telecom and emergency lighting. Long float-life under permanent charge and instant response to mains outages with no noticeable voltage drop.

## Why this stationary battery?

- **Instant response** when the mains drop, no voltage dip
- **Long life under 24/7 charge** optimised for permanent service
- **Compatible with your system** existing UPS units and alarm control panels

🔌 Voltage
4 V

⚡ Capacity
3,5 Ah C20

📏 Dimensions
90×34×65 mm

⚙️ Technology
AGM

🧭 Polarity
Positive on the left

## Description

## Stationary battery Fulbat FP4-3.5 3.5Ah 4V

4*V* Voltage
3.5*Ah* Capacity

Designed for UPS, alarms, telecoms and emergency lighting, the **Fulbat FP4-3.5** offers **3.5 Ah** with AGM technology on permanent float charge. It replaces the original battery without adaptation in UPS, alarm and emergency systems with a 90 × 34 × 65 mm format: same 3.5 Ah capacity and the positive terminal on the left.
- AGM technology: absorbed electrolyte, no spills, can be mounted at an angle.
- Long float life under permanent charge.
- Sealed and gas-free: suitable for cabinets and offices.
- Maintenance-free for its whole service life.

### What the Fulbat FP4-3.5 is for

Designed for UPS, alarms, telecoms and emergency lighting, the Fulbat FP4-3.5 is sealed, gas-free and suitable for technical cabinets and offices. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has FASTON-4.8 terminals.

### Dimensions, polarity and mounting

It has external dimensions of 90 × 34 × 65 mm. 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 FASTON-4.8 terminals, the system that anchors and connects it in the vehicle. Before replacing it, measure your current battery tray: if all three dimensions and the terminal positions match, the swap is direct and needs no adapters.

### Technology inside the Fulbat FP4-3.5

Within the Fulbat catalogue, the FP4-3.5 is the 3.5 Ah model designed for this application.
AGM (Absorbent Glass Mat) technology seals the electrolyte in glass microfibre. The result is a maintenance-free battery that is highly vibration-resistant and able to withstand deep discharges that would ruin a classic lead-acid battery.

### Why choose Fulbat batteries

Fulbat has manufactured in France since 1978 and specialises in motorcycles and light vehicles. Its catalogue is short and clear, covers almost the whole fleet and works only with sealed, leak-free batteries. At baterias.com we work directly with the manufacturer or its official distributor: real stock, brand-new product and official warranty.

### Official warranty

The Fulbat FP4-3.5 comes with the **manufacturer's official warranty** against manufacturing defects. If it fails through a defect within the warranty period, we replace it at no cost to you.

### Usage and maintenance tips

Replace all the batteries in the set at once and avoid environments continuously above 25 °C. Check the float voltage of the UPS or charger: a voltage that is too high shortens the life of a sealed battery.

### Delivery times and returns

Same-day dispatch from our warehouse for in-stock orders placed **before [[ks:cutoff]]**: 24-48 working hours in mainland Spain and Portugal, 3 to 5 days in the islands and the rest of Europe. Returns are accepted for **[[ks:return_days]] days** if the battery has not been used (free collection on the Iberian mainland). You will receive tracking by email.

## Frequently asked questions

### How is the Fulbat FP4-3.5 battery installed in the vehicle?

In most devices 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 devices 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 Fulbat FP4-3.5 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 Fulbat FP4-3.5 battery?

Dimensions (length × width × height) are 90×34×65 mm — also written as 90x34x65 mm — following the European DIN standard. Always measure the space in your device before buying: even one extra millimetre can prevent the hold-down clamp from closing. The height shown includes the terminals.

### Which batteries are equivalent to the Fulbat FP4-3.5?

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 devices. See the "Equivalents" section to view recommended options at the same performance level.


## Technical team (editorial authorship)

The FAQs, guides and comparisons on this site are reviewed by the baterias.com technical team — automotive battery specialists since 2015.

→ https://baterias.com/gb/technical-team

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*baterias.com — Automotive batteries · 2026-10-12*