The lithium battery for your ACE motorhome.
ACE is a Swift Group brand, built at Cottingham on the same production line conventions as Swift. Both the 1200 campervan range and the 1500 low-profile coachbuilt leave the factory on a sealed AGM that you can only safely half-use. A TITAN drops into the same kind of space, gives you the full rated capacity every time, and on a 3,500 kg Category B vehicle saves you useful kilograms you can put straight back into gear and water.
ACE: a Swift Group brand, two ranges, two base vehicles
ACE was revived by Swift Group for the 2026 season and sits at the value end of the Swift Group portfolio, while sharing the same Cottingham build conventions as Swift motorhomes. The range divides into two lines. The ACE 1200 is a panel van campervan on the Fiat Ducato, available in RL, GL and SL layouts plus pop-top T variants - 2 to 4 berth, 3,500 kg. The ACE 1500 is a low-profile coachbuilt on the Ford Transit, in GL, ET, DB and SL layouts - also 3,500 kg. Every current ACE model sits at the Category B licence limit, so payload is a genuine constraint on what you can carry, and that includes the leisure battery.
The factory leisure battery is a sealed lead-acid or AGM unit, typically 85Ah to 110Ah. On paper that sounds adequate; in practice you can only safely take a lead-acid down to around 50% before cycling life suffers, so the real usable reserve is closer to 40Ah to 55Ah. A TITAN lithium of the same or similar footprint gives you close to 100% usable capacity, charges faster from every source, and handles the deep daily cycling that motorhome life demands without degrading over a few seasons.
If you want the full picture of switching from lead-acid to lithium in a coachbuilt or campervan, the motorhome battery guide covers the fundamentals. To compare ACE against other British brands, the motorhome brands hub has the full picture.
Sizing a TITAN for your ACE
A starting point by model line. Both ranges are at the 3,500 kg Category B limit, so payload is a real consideration - a single lithium replacing a heavier lead-acid bank is often the right call even before you weigh up the extra capacity.
| Model | How it gets used | Good fit |
|---|---|---|
| ACE 1200 (Fiat Ducato campervan)Panel van and pop-top, 2-4 berth, 3,500 kg - weekend and touring use | Touring: lights, fridge, phones, occasional nights off hook-up | 100Ah to 120Ah |
| ACE 1200 (Fiat Ducato campervan)Same van, more off-grid nights, longer trips | Off-grid: heating, cooking, longer stays without hook-up | 120Ah to 150Ah |
| ACE 1500 (Ford Transit motorhome)Low-profile coachbuilt, 3,500 kg, site use and touring | Touring: heating, water pump, fridge, a few nights off-grid | 120Ah to 150Ah |
| ACE 1500 (Ford Transit motorhome)Same coachbuilt, more self-sufficient use | Off-grid: more devices, longer stays, sustained use | 150Ah to 180Ah |
These are starting points, not fixed rules. The honest figure comes from your own loads, not the model badge, so total them in the battery size calculator. Battery lockers and trays vary between model years and specifications, so measure your existing space - including terminal height - before ordering. For a larger bank you can run matched packs in parallel where the locker allows.
Where the leisure battery typically lives in an ACE
ACE follows Swift Group's established build conventions, so the leisure battery location follows the same patterns as other Swift-built vehicles - but exact positions are not published in detail for the ACE range, so always check your handbook and measure your available space before ordering.
- ACE 1200 campervan - typically under a seat or in a floor compartment. Following the Swift van-conversion convention, the 1200's AGM is typically housed under one of the cab seats or in a dedicated floor compartment. The low, flat DIN case suits exactly this kind of location - keeping weight down and central. Seat-base clearance can be tight on some layouts, particularly where swivel seats are fitted, so measure the void height carefully.
- ACE 1500 coachbuilt - typically an external locker or under a bed. Following the Swift SMART coachbuilt convention, the 1500's battery is more likely to be in an external habitation locker or in a compartment under the rear bed area. This gives more room for a slightly larger battery or for mounting a DC-DC charger and fusing alongside it.
Because the TITAN case is sealed to IP67, it handles the damp and dust of an underfloor or locker mount without issue. The RJ45 comms ports drop to IP32 while a cable is connected, so keep any plugged port clear of standing water. ACE battery box dimensions will vary between model years and specification levels - measure the space you have, including height to allow for the terminals, and match it to the battery dimensions before you buy.
Charging an ACE from alternator, solar and mains
An ACE motorhome or campervan charges its leisure battery from three sources: the engine alternator while driving, roof solar through an MPPT controller, and the mains charger when on hook-up. Lithium takes all three faster than the AGM it replaces, so a decent run on the road or a sunny afternoon puts real capacity back rather than a slow overnight trickle.
The alternator is where both ACE base vehicles need extra thought. Euro 6 Fiat Ducato engines on the 1200 series, and Euro 6 Ford Transit engines on the 1500 series, both run variable-voltage smart alternators that will not reliably fill a lithium battery on their own. The fix is a DC-DC charger - also called a battery-to-battery charger - wired between the starter battery and the leisure bank. We would fit a Victron Orion every time. It gives the lithium a clean, controlled charge and protects the starter battery from being drawn down. A standard split-charge relay does work and some builds already have one fitted, but it is not the most reliable way to charge lithium and some relays cause a backfeed that quietly skims 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 sizing guide, check your existing charger against the charger compatibility list, and size the battery around the gap your charging sources cannot cover overnight. Every TITAN carries a custom BMS with a built-in low-temperature heater so it charges safely down to -30C, and comes with a lifetime, fully transferable warranty.
