Auxiliary battery for Tesla FT438-U1R 12V 35Ah 438A AGM
Specifications
| Brand | FULLRIVER |
|---|---|
| Part number | FT438-U1R |
| Voltage (V) | 12 |
| Capacity (C20) | 35Ah (c20) |
| Length | 196.00 cm |
| Width | 131.00 cm |
| Height | 192.00 cm |
| Weight | 11.30 Kgs |
| Terminal type | M6 + TP26 (SAE) |
€173.95
VAT included
Fullriver FT438-U1R 12V 35Ah 438A is a ready-to-use passenger car battery, sealed and maintenance-free. Delivers the cranking amps the engine needs in cold weather and keeps stable voltage for modern car loads (ECU, sensors, climate control, infotainment).
Why this car battery?
- Original-equipment qualitywithout dealership prices
- Lasts 4 to 6 yearsbuy once instead of twice
- Real human tech supportif you have any doubts before buying
Voltage
12 V
Capacity
35 Ah
Cold cranking
438 A
Dimensions
196×131×192 mm
Weight
11,3 kg
Model
Full Throttle Series
Auxiliary battery Fullriver FT438-U1R Full Throttle Series 35Ah 438A 12V
12VVoltage
35AhCapacity
438ACold cranking
11.30kgWeight
Designed for the auxiliary network of cars with advanced Start-Stop and heavy electronics, the Fullriver FT438-U1R from the Full Throttle Series range stabilises the voltage with 35 Ah with AGM technology. It replaces the original battery without adaptation in vehicles with an auxiliary battery with a 196 × 131 × 192 mm format: same 35 Ah capacity.
- AGM technology: absorbed electrolyte, no spills, can be mounted at an angle.
- Stabilises the onboard network voltage.
- Sealed AGM: safe when installed in the cabin.
- Maintenance-free.
What the Fullriver FT438-U1R is for
As an auxiliary battery, the Fullriver FT438-U1R works alongside the main one; replace it when the vehicle reports a fault in the support network. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 11.30 kg and M6 + TP26 (SAE) terminals.
Size, terminals and hold-down of the Fullriver FT438-U1R
The Fullriver FT438-U1R is made in the 196 × 131 × 192 mm format and weighs 11.30 kg. It uses M6 + TP26 (SAE) 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.
Why choose Fullriver batteries
Fullriver specialises in deep-cycle AGM batteries for mobility, marine, solar and traction. Its DC and HC series are known for their tolerance to deep discharge and long cycle life. All the Fullriver batteries in our catalogue are genuine product, recently manufactured and covered by the manufacturer's warranty.
The Fullriver FT438-U1R: Full Throttle Series range and AGM technology
Within the Fullriver catalogue, the Full Throttle Series series groups the references designed for this use. The FT438-U1R is the 35 Ah model of that family, with the same performance as its siblings in other sizes.
In an AGM battery the electrolyte is absorbed in glass-fibre separators: there is no free liquid, it cannot spill and it can be mounted at an angle. That construction lowers internal resistance, speeds up recharging and multiplies cycle life compared with a conventional battery.
Usage and maintenance tips
The auxiliary battery works alongside the main one: if a support-network fault warning appears, check both. Charge with a charger that has an AGM mode: it limits the voltage and protects the glass-fibre separators.
Official warranty
The Fullriver FT438-U1R 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.
When you get it and how to return it
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-FULLRIVER-FT438-U1R
Data sheet
- Brand
- FULLRIVER
- Reference
- FT438-U1R
- Model
- Full Throttle Series
- Voltage (V)
- 12
- Length
- 196.00 cm
- Width
- 131.00 cm
- Height
- 192.00 cm
- Weight
- 11.30 Kgs
- EAN
- 810233030640
- Terminal type
- M6 + TP26 (SAE)
- Cold cranking amps (EN)
- 438A
- Capacity (C20)
- 35Ah (c20)
- Case type
- U1R
Specific References
- MPN
- FT438-U1R
How to change the battery
Step-by-step guide to replace your car battery in 15-30 minutes (longer if the battery is under the seat or in the boot) without losing vehicle settings.
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.
Step 2. Locate the battery
Open the bonnet. The battery is usually in the engine bay, but in many modern cars it may be in the boot or under the passenger seat. Check the manual if you cannot find it.
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.
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.
Step 5. Remove the old battery
Loosen the bottom hold-down clamp with the same wrench. Lift the battery carefully (it can weigh 15-25 kg). Clean the tray with a brush and baking soda if there is corrosion.
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.
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.
Step 8. Verify the engine starts
Close the bonnet. Start the engine to confirm everything works. On cars with Start-Stop or a BMS, you may need to register the battery via OBD so the alternator applies the correct charging profile.
Frequently asked questions
How is the Fullriver FT438-U1R battery installed in the vehicle?
In most cars 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 cars with Start-Stop or BMS, register the battery via OBD so the alternator applies the correct charging profile.
How long does the Fullriver FT438-U1R battery last?
Expected lifespan of the Fullriver FT438-U1R 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 size is this battery?
Dimensions (length × width × height) are 196×131×192 mm — also written as 196x131x192 mm — following the European DIN standard. Always measure the space in your car 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 FT438-U1R 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 cars. See the "Equivalents" section to view recommended options at the same performance level.
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