Q-battery 12SEM-135 · Caravan battery 12V 135Ah
Specifications
| Brand | Q-battery |
|---|---|
| Part number | 12SEM-135 |
| Voltage (V) | 12 |
| Capacity (C20) | 135Ah (c20) |
| Technology | Lead-acid |
| Length | 349.00 cm |
| Width | 175.00 cm |
| Height | 290.00 cm |
| Weight | 37.80 Kgs |
Q-battery 12SEM-135 12V 135Ah is a leisure battery for campers, motorhomes and caravans. Designed to power the entire interior kit (fridge, heater, water pump, USB, LED lighting) for several days off-grid, with no need to plug into a campsite hookup.
Why this caravan battery?
- Real off-grid autonomyno campsite hookup needed
- Lasts the whole seasonhandles daily discharges without capacity loss
- Powers it all at oncefridge, water pump, LED and USB without issues

Mobility battery Q-Battery 12SEM-135 Semitraction Battery 135Ah 12V
The Q-Battery 12SEM-135 with conventional lead-acid technology delivers 135 Ah at 12 V with the cycle life that power wheelchairs, mobility scooters and light electric vehicles demand. Its 349 × 175 × 290 mm and the positive terminal on the right make it the exact replacement for the 135 Ah battery fitted as standard to many power wheelchairs and mobility scooters.
- Sealed AGM/GEL: safe indoors and in transport.
- Good balance of capacity, cranking power and price.
- Approved for air and sea transport (VRLA).
- No maintenance, no water top-ups.
What the Q-Battery 12SEM-135 is for
The Q-Battery 12SEM-135 is designed for power wheelchairs, mobility scooters and light electric vehicles. Wheelchairs and scooters normally use two identical batteries in series: replace them together. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 37.80 kg, A-Pole terminals and B0 hold-down.
Size, terminals and hold-down of the Q-Battery 12SEM-135
It has external dimensions of 349 × 175 × 290 mm and weighs 37.80 kg. The positive terminal on the right decides which side the cables end up on: it is the detail that causes most buying mistakes, so check it before ordering. It uses a B0 hold-down and A-Pole 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.
The Q-Battery 12SEM-135: Semitraction Battery range and conventional lead-acid technology
The 12SEM-135 is part of the Q-Battery Semitraction Battery range. Choosing the right reference within the series comes down to capacity, dimensions and terminals: technology and quality are common to the whole family.
The conventional lead-acid battery remains the most widespread technology thanks to its balance of capacity, cranking current and price. Well maintained and kept charged, it offers years of reliable service in vehicles without Start-Stop.
What Q-Battery does differently
Q-Battery specialises in AGM and GEL VRLA batteries for UPS, telecoms, solar and deep cycling, with long-life and tubular-plate series for industrial use. We guarantee that every Q-Battery arrives new, charged and with the manufacturer's full warranty.
Warranty and coverage
The Q-Battery 12SEM-135 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
Recharge the wheelchair or scooter after each use and do not leave it discharged for days: lead sulphates and loses capacity. On batteries with filler caps, check the electrolyte level and top up only with distilled water.
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.
Data sheet
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BrandQ-Battery
-
Reference12SEM-135
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ModelSEMITRACTION BATTERY
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Voltage (V)12
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Length349.00 cm
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Width175.00 cm
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Height290.00 cm
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Weight37.80 Kgs
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TechnologyLead-acid
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Terminal layoutPositive terminal on the right
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Terminal typeA-Pole
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Hold-downB0
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Capacity (C20)135Ah (c20)
Specific References
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EAN134250889600273
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MPN12SEM-135
Codes and references Q-battery 12SEM-135
| Brand | Q-battery |
|---|---|
| Manufacturer range | SEMITRACTION BATTERY |
| Manufacturer part number (MPN) | 12SEM-135 |
| Also known as | 12SEM135 · 12SEM 135 |
| EAN-13 barcode | 4250889600273 |
| Dimensions (length × width × height) | 349 × 175 × 290 mm (349x175x290) |
Recommended accessories
Frequently asked questions
How do I change this battery step by step?
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 — with positive on the right 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 Q-battery 12SEM-135 battery last?
Expected lifespan of the Q-battery 12SEM-135 is 4 to 6 years in regular device use without 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 Q-battery 12SEM-135 battery?
Dimensions (length × width × height) are 349×175×290 mm — also written as 349x175x290 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 polarity does the Q-battery 12SEM-135 battery have?
Polarity: positive on the right. To identify it, place the battery in front of you with the terminals facing you and check which side the positive (+, marked with a red ring) is on. Before buying, verify the polarity matches your current battery: switching polarity forces longer cables or system reconfiguration, with short-circuit risk.
Which batteries are equivalent to the Q-battery 12SEM-135?
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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