The lithium battery for your Renault Master.
The Master is a big, value panel van and one of the most popular conversion bases with self-builders. No factory leisure battery - you fit it during the conversion, which means you get to choose exactly what goes in. A drop-in DIN lithium gives you real, usable capacity from a case built to last the life of the van.
A great conversion base with some useful badge-twin facts
The Renault Master has been the go-to big van for self-build conversions in Europe for years. It is front or rear-wheel drive, available in panel-van and chassis-cab forms, and well-priced new and used. The Master III ran from 2010 to 2024 before being replaced by the all-new Master IV, launched in 2024 with UK sales from early 2025. Both generations share the same wide, square load bay that self-builders like.
Two badge-twins are worth knowing about. The Nissan Interstar - the name that returned in 2022 - is a rebadged Renault Master. If you have a current Interstar, everything on this page applies to you. The older Nissan was the NV400, which was also a rebadged Master of the previous generation.
The Vauxhall Movano is a different story. The pre-2021 Movano was indeed a rebadged Master and everything here applied to it too. Since 2021, however, the Vauxhall Movano has been built on the Stellantis platform shared with the Fiat Ducato and Peugeot Boxer - it is now a fundamentally different van. If you have a 2021-on Movano, the Fiat Ducato battery page is the right place to start.
The Master is less common than the Fiat Ducato or Ford Transit as a base for UK mass-market coachbuilt motorhomes, but it is a solid and well-specified self-build platform. If you are starting from a bare shell, the van conversion guide walks through planning around the battery from the start.
Sizing a Master conversion
A starting point by build. Size to how you actually use the van, not the van itself.
| Build | How it gets used | Good fit |
|---|---|---|
| Compact or day-van buildLights, fridge, phones, the odd night off hook-up | Modest | 100Ah to 150Ah |
| Full conversionHeating, water pump, fridge, devices, days off-grid | Typical vanlife | 150Ah to 230Ah |
| Off-grid or inverter cookingInduction hob, big inverter, living aboard | Heavy, sustained | 230Ah to 460Ah |
| Working or welfare vanInverter for tools, charging packs, welfare gear | Bursty, high current | 180Ah to 330Ah |
These are starting points, not fixed rules. The honest figure comes from your loads rather than the size of the van, so total them in the battery size calculator. For bigger banks you can run matched packs in parallel or step up to a single larger battery where space allows.
Where the battery fits in a Master conversion
There is no factory leisure battery in the panel-van Master - the starter battery sits in the cab floor, and all habitation electrics are fitted during the conversion. That gives you a free choice of where the leisure battery lives. The flat DIN case suits the two most common spots:
- Under the driver or passenger seat. This is the tidy choice for smaller banks - it keeps the weight forward and central, and the low terminal profile on the DIN case helps clear the seat base, which can be tight depending on the seat configuration. Measure the available height, including the clearance above the terminals, before you order.
- In the rear habitation. Larger banks usually sit under the sofa base, bed frame or in the garage, with room to mount the charger and fusing alongside. This is the most practical home for a 230Ah or above. Where you have a choice, keeping the battery inside the heated habitation space is better for performance in cold weather.
The case is sealed to IP67, so it handles moisture well in most locations. The one caveat: the RJ45 comms ports drop to IP32 while a cable is plugged in, so keep connected ports clear of standing water. Wherever the battery lives, keep it accessible enough to read the terminals, keep it off a direct heat source, and measure the full space - including terminal height - before you order.
Charging a Master conversion
A Master conversion charges from three sources: the engine alternator, roof solar through an MPPT, and mains hook-up. Lithium takes all three happily and charges far faster than lead-acid, so a decent drive or a sunny afternoon puts real capacity back rather than a trickle.
The alternator is the part to get right. Euro 6 Masters - registered from around 2015 on the Master III - and the 2024 Master IV both run a variable-voltage smart alternator. A smart alternator will not reliably fill a lithium battery on its own, so the correct solution is a DC-DC charger, also called a battery-to-battery charger. We would fit a Victron Orion every time. It gives the lithium a clean, controlled charge and protects the starter battery. A split-charge relay is a less reliable way to charge lithium, and some relays cause a backfeed that quietly skims around the top 15% off your usable capacity. Feeding straight off the alternator with no relay and no DC-DC is not something we recommend.
Plan the roof with the solar guide, check your charger against the compatibility list, and size the battery around the gap your charging cannot cover. Every TITAN carries a custom BMS, charges safely down to -30C, and comes with a lifetime, fully transferable warranty.
