# Fulbat FP12-4L · UPS battery 12V 4Ah

![Fulbat FP12-4L · UPS battery 12V 4Ah](https://bateriasonline.es/660-home_default/fulbat-fp12-4l.jpg)

> Fulbat FP12-4L: 4 Ah UPS battery, 195×47×76 mm, positive terminal on the left, AGM. Equivalent to Ritar RT1245S. Ask for a no-obligation quote.

**Category:** [UPS batteries](https://bateriasonline.es/en/ups-batteries) → [Fulbat](https://bateriasonline.es/en/fulbat-batteries)

- **Canonical URL**: https://bateriasonline.es/en/fulbat-fp12-4l
- **Language**: en
- **Brand**: Fulbat
- **Reference**: BOL-FULBAT-FP12-4L
- **MPN**: FP12-4L
- **Last updated**: 2026-10-27

## Technical specifications

| Feature | Value |
|---|---|
| Brand | Fulbat |
| Range | FULBAT FP General Purpose |
| Application | UPS systems |
| Technology | AGM |
| Voltage | 12 V |
| Capacity | 4 Ah |
| Length | 195 mm |
| Width | 47 mm |
| Height | 76 mm |
| Weight | 1.38 kg |
| Polarity | Positive terminal on the left |
| Terminal type | T1 |

## Quick description

The Fulbat FP12-4L is an UPS battery with 12 V and 4 Ah, measuring 195 × 47 × 76 mm, with the positive terminal on the left.

## Description

## Where the Fulbat FP12-4L fits

The Fulbat FP12-4L is a VRLA AGM battery for UPS and uninterruptible power systems: it stays charged for years waiting for an outage and delivers the energy instantly when it comes. Check dimensions, terminal type (F1 or F2) and capacity so it fits the unit.
The FP12-4L belongs to the Fulbat FULBAT FP General Purpose range. [More Fulbat batteries](https://bateriasonline.es/en/fulbat-batteries)

## Equivalents and alternatives to the Fulbat FP12-4L

Other AGM batteries that fit the FP12-4L's tray with the same polarity: an AGM can only be replaced by another AGM.

| Model | Technology | Capacity | Dimensions (mm) |
|---|---|---|---|
| Ritar RT1245S | AGM | 4.5 Ah | 195 × 47 × 76 |

## Fulbat FP12-4L vs FP12-2.6 and FP12-3.2FR: differences

How the FP12-4L compares with Fulbat batteries of similar size and capacity:

| Model | Capacity | Dimensions (mm) | Positive | Weight |
|---|---|---|---|---|
| Fulbat FP12-4L (this one) | 4 Ah | 195 × 47 × 76 | left | 1.38 kg |
| Fulbat FP12-2.6 | 2.6 Ah | 178 × 35 × 66 | – | 0.91 kg |
| Fulbat FP12-3.2FR | 3.2 Ah | 134 × 67 × 65.5 | – | 1.35 kg |

- Fulbat FP12-2.6: 1.4 Ah less, a different case (178 × 35 × 66 mm).
- Fulbat FP12-3.2FR: 0.80 Ah less, a different case (134 × 67 × 65.5 mm).

## What it means that the FP12-4L is AGM

The FP12-4L is AGM: the electrolyte is absorbed in glass fibre mats, so it is sealed and spill-proof. It withstands many more cycles than a conventional lead battery, at the cost of being more sensitive to overcharging.

## Check this before ordering the Fulbat FP12-4L

- The FP12-4L needs 195 × 47 × 76 mm of space: measure it with the hold-down clamp in place.
- With the terminals facing you, the positive terminal of the FP12-4L is on the left.
- Your current battery should say about 4 Ah; a little more is also fine.

## Part numbers and codes for the Fulbat FP12-4L

The FP12-4L is listed under these codes on labels, in garages and in catalogues:

| Commercial reference | FP12-4L |
|---|---|
| Terminal type | T1 |
| Not to be confused with | Fulbat FP12-4.5 (4.5 Ah), Fulbat FP12-40 (40 Ah) |

## Frequently asked questions about the Fulbat FP12-4L

### FP12-4L or FP12-2.6: which one suits me?

Compared with the FP12-4L, the Fulbat FP12-2.6 has 1.4 Ah less. With 4 Ah, the FP12-4L runs longer between charges than the FP12-2.6 (2.6 Ah). Mind the space: the FP12-2.6 measures 178 × 35 × 66 mm.

### How much does the Fulbat FP12-4L weigh?

1.38 kg, with 4 Ah of capacity. For reference, the Fulbat FP12-2.6 (2.6 Ah) weighs 0.91 kg.

### Which battery is equivalent to the Fulbat FP12-4L?

Only other AGM batteries with its dimensions and polarity: Ritar RT1245S. Neither an EFB nor a conventional battery replaces the FP12-4L.

### Which side is the positive terminal on the Fulbat FP12-4L?

On the FP12-4L, the positive terminal is on the left with the terminals facing you: compare it with your current battery, because with reversed polarity the cables will not reach.

### Which charger does the Fulbat FP12-4L need?

A charger with an AGM mode that limits voltage to about 14.4-14.7 V. Never an old unregulated charger: overcharging dries out an AGM beyond repair.

## More batteries to compare with the FP12-4L

- [More uPS batteries](https://bateriasonline.es/en/ups-batteries)
- [More Fulbat models](https://bateriasonline.es/en/fulbat-batteries)
- [Ritar RT1245S](https://bateriasonline.es/en/ritar-rt1245s) · 4.5 Ah, 195×47×76 mm

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*bateriasonline.es — Batteries and accessories · 2026-11-10*