Volkswagen T5, T6 and T6.1 leisure batteries
SpaziouSpaziou Magazine · VW T5 / T6 / T6.1 · Power
Volkswagen T5, T6 and T6.1 campervan leisure battery
In Transporter and California, space matters as much as capacity. Supply fridge, lighting and electronics without sacrificing too much storage or fitting a battery you cannot recharge.
What determines size
One of the largest continuous loads.
DC-DC charging can substantially reduce the reserve needed if you drive daily.
Fixed or portable depending on roof, pop-top and travel style.
Seat-base or cabinet placement determines format and ventilation.
Start with the consumption calculator then use the battery calculator.
Under-seat · T5 / T6 / T6.1
Low-profile batteries worth measuring
In Transporter and California, “Mini” on the box is not enough. Measure usable volume with the actual base, wiring and seat movement. One documented reference is Roamer 230SEATBASE5 measure 285 × 331 × 182 mm and is designed for a swivel-seat base; the manufacturer explicitly cites VW T5/T6/T7 installations.
| Model | Dimensions | Spaziou interpretation |
|---|---|---|
| Roamer 230SEATBASE5 | 285 × 331 × 182 mm | Manufacturer’s specific seat-base statement and cited experience in VW T5/T6/T7. |
| Super B Epsilon 100Ah | 278 × 175 × 190 mm | DIN H6/LN3 format; useful height, but must be physically checked in the exact base. |
Before buying, allow space for terminals, cables, fuse, mounting and the swivel-base sweep. If it only fits on its side, first check that the manufacturer permits that orientation.
How to measure a T5 / T6 / T6.1
Do not measure only visible height
Remove only maintenance covers or designated service parts and measure space without altering structures or safety systems. Record usable length, width and height in millimetres, plus obstacle positions: connectors, wiring looms, heating, relays, pretensioners or bolts may occupy a corner even if the overall rectangle looks sufficient.
Next trace the cable routes. A battery 182 or 190 mm high may leave space above its case yet be awkward if its positive terminal sits under a rail or the cable must bend immediately. Allow for terminal protection and removal for servicing too.
With a swivel base, check several seat positions. Minimum clearance may differ from the driving position. Do not remove protection or expose a terminal to gain millimetres.
230 Ah under the seat: high capacity does not replace system design
Roamer 230SEATBASE5 specifies 230 Ah at 12.8 V, 285 × 331 × 182 mm and up to 300 A continuous. This shows how much capacity a specific seat base can hold, not that 230 Ah suits everyone. First calculate daily Wh and how DC-DC, solar or mains will replenish them.
If 100 Ah meets demand and recharges daily, more capacity may add cost and weight without solving a problem. Working, continuous fridge use or long stops may justify extra reserve, provided charging is sized accordingly.
The correct sequence is: consumption → desired autonomy → charging → available space → compatible battery. Not the reverse.
Frequently asked questions
Fixed battery or portable station?
Fixed integrates a permanent conversion; portable adds modularity.
Is the same location suitable for T5 and T6.1?
Do not assume it: check seat, furniture and exact configuration.
Follow the system, not a single part.
Start with consumption, then check runtime and weight to coordinate battery and solar.
Volkswagen Commercial Vehicles has specific chapters on vehicle battery, wiring/fuses, electrical retrofits and special-vehicle interface. Do not assume identical electrics across T5, T6 and T6.1.
Volkswagen Commercial Vehicles · Body Builder Guidelines Transporter T6.1 ↗
