# Ritar RT645 · UPS battery 6V 4.5Ah

![Ritar RT645 · UPS battery 6V 4.5Ah](https://bateriasonline.es/3065-home_default/ritar-rt645.jpg)

> Ritar RT645: 4.5 Ah UPS battery, 70×47×107 mm, AGM. Equivalent to Fulbat FP6-4.5 and Long WP4.5-6.

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

- **Canonical URL**: https://bateriasonline.es/en/ritar-rt645
- **Language**: en
- **Brand**: Ritar
- **Reference**: BOL-RITAR-RT645
- **MPN**: RT645
- **Price**: 33,32 € (VAT incl., Spain)
- **Last updated**: 2026-11-07

## Technical specifications

| Feature | Value |
|---|---|
| Brand | Ritar |
| Range | RITAR RT |
| Application | UPS systems |
| Technology | AGM |
| Voltage | 6 V |
| Capacity | 4.5 Ah |
| Length | 70 mm |
| Width | 47 mm |
| Height | 107 mm |
| Weight | 0.65 kg |
| Terminal type | F1 |

## Quick description

The Ritar RT645 is an UPS battery with 6 V and 4.5 Ah, measuring 70 × 47 × 107 mm.

## Description

## Who the Ritar RT645 is for

The Ritar RT645 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. Before ordering the RT645, check the terminal type and terminal orientation in your UPS.
The RT645 belongs to the Ritar RITAR RT range. [The full range of Ritar batteries](https://bateriasonline.es/en/ritar-batteries)

## Inside the RT645: AGM technology

The RT645 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.

## Ritar RT645 vs RT632

How the RT645 compares with Ritar batteries of similar size and capacity:

| Model | Capacity | Dimensions (mm) | Weight |
|---|---|---|---|
| Ritar RT645 (this one) | 4.5 Ah | 70 × 47 × 107 | 0.65 kg |
| Ritar RT632 | 3.2 Ah | 134 × 35 × 67 | 0.6 kg |

- Ritar RT632: 1.30 Ah less, a different case (134 × 35 × 67 mm).

## Equivalents and alternatives to the Ritar RT645

Other AGM batteries that fit the RT645's tray with the same polarity: an AGM can only be replaced by another AGM.

| Model | Technology | Capacity | Dimensions (mm) |
|---|---|---|---|
| Fulbat FP6-4.5 | AGM | 4.5 Ah | 70 × 47 × 106 |
| Long WP4.5-6 | AGM | 4.5 Ah | 70 × 47 × 106 |
| Fulbat FP6-4 | AGM | 4 Ah | 70 × 47 × 106 |
| Long WP5-6 | AGM | 5 Ah | 70 × 47 × 106 |
| Long WPS4-6 | AGM | 4 Ah | 70 × 47 × 106 |
| Fulbat FP6-6 | AGM | 6 Ah | 70 × 47 × 106 |

## Part numbers and codes for the Ritar RT645

The RT645 is listed under these codes on labels, in garages and in catalogues:

| Commercial reference | RT645 |
|---|---|
| Terminal type | F1 |

## Before ordering the RT645, check this

- Your current battery should say about 4.5 Ah; a little more is also fine.
- Measure the space: the RT645 takes up 70 × 47 × 107 mm.

## Frequently asked questions about the Ritar RT645

### RT645 or RT632: which one suits me?

Compared with the RT645, the Ritar RT632 has 1.30 Ah less. With 4.5 Ah, the RT645 runs longer between charges than the RT632 (3.2 Ah). Mind the space: the RT632 measures 134 × 35 × 67 mm.

### How much does the Ritar RT645 weigh?

0.65 kg, with 4.5 Ah of capacity. For reference, the Ritar RT632 (3.2 Ah) weighs 0.6 kg.

### Which battery is equivalent to the Ritar RT645?

Only other AGM batteries with its dimensions and polarity: Fulbat FP6-4.5, Long WP4.5-6 and Fulbat FP6-4. Neither an EFB nor a conventional battery replaces the RT645.

### Which charger does the Ritar RT645 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.

## Other options if you are unsure about the RT645

- [All uPS batteries](https://bateriasonline.es/en/ups-batteries)
- [More Ritar models](https://bateriasonline.es/en/ritar-batteries)
- [Q-Battery 6LS-4.5](https://bateriasonline.es/en/q-battery-6ls-4-5) · 4.5 Ah, 70×47×100 mm
- [Fulbat FP6-4.5S](https://bateriasonline.es/en/fulbat-fp6-4-5s) · 4.5 Ah, 67×67×109 mm

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