Ritar RT645 · Stationary UPS battery 6V 4.5Ah AGM
Specifications
| Brand | RITAR |
|---|---|
| Part number | RT645 |
| Voltage (V) | 6 |
| Capacity (C20) | 4 5Ah (c20) |
| Technology | AGM |
| Length | 70.00 mm |
| Width | 47.00 mm |
| Height | 107.00 mm |
| Terminal type | F1 |
Ritar RT645 6V 4Ah 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 responsewhen the mains drop, no voltage dip
- Long life under 24/7 chargeoptimised for permanent service
- Compatible with your systemexisting UPS units and alarm control panels

Stationary battery Ritar RT645 RT 4Ah 6V
The 6 V, 4 Ah Ritar RT645 stationary battery from the RT range with AGM technology is designed for UPS, alarms, telecoms and emergency lighting. It measures 70 × 47 × 107 mm, the format sought by anyone replacing a 4 Ah battery in UPS, alarm and emergency systems.
- Long float life under permanent charge.
- AGM technology: absorbed electrolyte, no spills, can be mounted at an angle.
- Maintenance-free for its whole service life.
- Sealed and gas-free: suitable for cabinets and offices.
Dimensions, polarity and mounting
The Ritar RT645 is made in the 70 × 47 × 107 mm format and weighs 0.65 kg. It uses F1 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.
What the Ritar RT645 is for
With 4 Ah, the Ritar RT645 gives your UPS or emergency system the autonomy it needs. Replace all the batteries in the set at once. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 0.65 kg and F1 terminals.
The Ritar RT645: RT range and AGM technology
The RT is the Ritar range the RT645 belongs to: it shares the same construction and quality criteria with the rest of the series, and varies in capacity and format to suit each vehicle.
AGM means the acid is held in a glass mat instead of floating free. That is why the battery can be installed in the cabin without gases, survives more cycles and recovers its charge quickly.
Why choose Ritar batteries
Ritar is one of the world's largest VRLA battery manufacturers. Its RA, RT, RL, HR and FT series equip UPS, telecoms and solar systems worldwide with very consistent quality. We guarantee that every Ritar arrives new, charged and with the manufacturer's full warranty.
Official warranty
The Ritar RT645 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.
Care and maintenance
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
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 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.
Recommended accessories
Frequently asked questions
Is the Ritar RT645 an AGM battery and what are the benefits of AGM?
Yes. The RT645 from Ritar 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 devices with advanced Start-Stop and regenerative braking. Expected lifespan: 5-8 years under normal conditions.
How do I fit the RT645 model in my device?
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 our blog. 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 long does the Ritar RT645 battery last?
Expected lifespan of the Ritar RT645 is 5 to 8 years in mild-climate device 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 Ritar RT645 battery?
Dimensions (length × width × height) are 70×47×107 mm — also written as 70x47x107 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.
What are the equivalents of the RT645 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 devices. See the "Equivalents" section to view recommended options at the same performance level.
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