TITAN 280Ah 12V Lithium Leisure Battery – Maximum 12V Capacity for Motorhome, Marine & Off-Grid

The industrial 345mm footprint is the standard format for big lead-acid leisure banks — common in marine engine bays, off-grid cabinets and larger motorhome battery compartments. Where smaller 12V lithiums need to be paralleled to deliver this capacity, this is one battery that does the lot.

All TITAN batteries use lithium iron phosphate (LiFePO₄) prismatic cells — the most thermally and chemically stable lithium chemistry available. No cobalt, no nickel, no off-gassing, no acid. The trade-off is a slightly lower cell voltage (3.2V per cell, 4 cells = 12.8V) and lower energy density than the NMC cells used in EVs. In return, you get lifespans that make NMC look disposable: 3,000 to 25,000 cycles depending on use, against NMC’s 1,000 to 2,500.

A cycle is one full discharge plus one full recharge. Cycle count scales with how deep you take each discharge:

• 100% DoD — 3,000 cycles (~8.2 years at one cycle a day)
• 80% DoD — 6,000 cycles
• 50% DoD — 12,000 cycles (over 30 years of daily use)
• 30% DoD — 15,000+ cycles

TITAN cells are long, flat prisms that fill the rectangular case end to end. Cylindrical cells leave gaps between every cell and are much harder to repair (lots of spot welding), so TITAN pays the extra cost for prismatic and passes the capacity gain back to you — especially valuable in this large industrial case where cell density translates directly to pack capacity.

• Aluminium cell casing disperses heat evenly — even at full 250A BMS allowance, peak cell temperatures sit around 45°C, well inside spec
• Thermal runaway territory only starts around 100°C — nowhere near normal operation
• Heater mats also work better with prismatic cells — every cell sits against the heating element, rather than only the outer ring of a cylindrical pack

Matching this 280Ah in lead-acid means six and a half Exide ER550 115Ah batteries paralleled up to 750Ah. One TITAN 280Ah replaces the lot — massive savings in space, weight and cabling, with no gassing so it can live anywhere.

25kg. Not 169kg.

There isn’t a single lead-acid battery that comes close to this capacity. The honest comparison is six and a half ER550-class leisure batteries paralleled together to match the usable Wh — that’s 169kg of lead-acid sitting in your install. One TITAN does it in 25kg. A 144kg saving matters on a motorhome’s drive-axle plate, at the ferry scales, on a yacht’s waterline, and at the pump.

99% electrically efficient

Almost every watt you put in comes back out. A great partner for solar — no wasted incoming charge — and happy to accept very high charge currents: 0 to 95% in under two hours at 100A+.

The 250A continuous BMS comfortably handles the kind of kit a serious off-grid cabin or motorhome owner actually wants to run:

• 3,000W+ inverters: induction hobs, full-size microwaves, electric kettles, espresso machines
• Air conditioning: small AC units off-grid for serious comfort in hot weather
• Heat pumps & electric water heaters: short bursts on inverter
• Large compressor fridges, freezers & chest coolers: all-day cycling without BMS trips
• Winches & high-surge DC motors: 280A peak handles cold-start spikes
• Solar charge currents to 100A+: 0–95% in under two hours when the sun cooperates

The battery management system is the circuit board between the cells and the terminals. It’s the difference between a lithium battery that lasts 15 years and one that self-destructs in two. Most brands fit an off-the-shelf board with generic parameters. TITAN doesn’t.

The TITAN BMS is custom, with parameters tuned to the exact cell spec used. That lets the cells run right up to their real safe working limits without compromising protection. It’s also how an extra 5–10% usable capacity comes out of every cell — a 280Ah can show as 295Ah fully charged. The bonus capacity isn’t guaranteed batch to batch, but the BMS re-maps its 100% reading automatically so the app always shows what you actually have.

Over-discharge, over-voltage, under-voltage, over-current, short-circuit, over-temperature, under-temperature, cell balance faults and more. All protections are temporary — they either self-reset or clear the moment the battery is put back on charge. The 250A continuous current allowance on this model is class-leading thanks to premium MOSFETs, oversized heat sinks and properly sized internal cabling.

Passive balancing is cheap: cells bleed off to each other and that’s it. Active balancing actively moves energy between cells, protecting the weakest cell from doing all the work. Most brands pick one. TITAN runs both — passive for small voltage deltas, active for larger ones. Keeps the BMS’s own power draw low while still giving the full benefit of active balancing. Automatic, most active when charging above 3.4V per cell, full effect between 90–100% SOC.

Lithium cannot be charged below 0°C without cell damage. The built-in heater mat wraps the internal pack and kicks in automatically at around 2°C whenever there’s an incoming charge current.

• Draws from the charger first; if the charger can’t keep up, pulls up to 3.6A from the battery itself
• Brings cell temperature to 10°C before routing charge back to the cells
• Expect roughly 20 extra minutes on charge time in the cold
• Discharge is unaffected and works down to −20°C

A fully discharged lithium battery left for months can be a lithium battery that doesn’t come back. Automatic hibernation triggers after several days of inactivity at low SOC. The battery stops outputting but retains enough headroom to last around 6 months (longer on a pack this size) before any cell risk. Wakes up the moment you put it on charge or open the app.

Inverters, water pumps, motor movers and compressors can pull 1,000A+ for a microsecond on start-up. Many BMSs read that as a short circuit and trip. The TITAN is tuned to ride those spikes without nuisance shutdowns, so start-up loads behave exactly the way they did on your old lead-acid bank.

Comms ports on the case let the battery talk to compatible inverters, chargers and GX devices. Defaults to Victron CANBUS (VE.CAN and BMS.CAN) and is compatible with Victron DVCC out of the box — particularly important on a pack this size for accurate SOC reporting and proper charge management on a Multiplus II or similar inverter/charger. The data mode can be switched to other brands or protocols on request — flag it in the order notes and TITAN’s engineers will set it before dispatch.

Known working with:

• Victron GX devices (default) — CAN
• Growatt — CAN
• Sacolar — CAN
• Goodwe — CAN
• Voltronic Power — RS485
• Sofar — CAN
• Sorotec — CAN or RS485
• Deye / SunSynk — CAN or RS485
• Solis — CAN
• Luxpower — CAN
• Pylon Tech — CAN or RS485
• Sol-Ark — CAN
• SRNE — RS485
• MUST — CAN
• SMA — CAN
• MEGAREVO — CAN
• MPP Sola — RS485
• TBB Power — CAN
• Senergy — CAN
• Schneider Electric — CAN
• Aiswei — CAN
• SMK — RS485
• Foxess — CAN
• SunGrow — CAN

Cable kits for every protocol are available separately — please get in touch if you need one. Multiple batteries can be paralleled (up to 8 = 2,240Ah) with their data merged via Ethernet (CAT-V).

Sized to swap straight in for an industrial 345mm lead-acid bank. Confirm your existing footprint against the 345mm × 190mm × 265mm case dimensions and that your cabling will reach the M8 terminal posts.

• Charger: if your charger has no dedicated lithium preset, AGM or “Sealed” modes are accepted. Aim for max charge voltage of 14.4V
• Split-charge relays & DC-DC chargers: compatible out of the box
• Terminals: high-performance copper M8 bolt terminals as standard — the format used by industrial lead-acid leisure batteries in this size class. Two M8 bolts and spring washers are included for direct ring-terminal cabling. Need round (SAE/automotive) terminals instead? TITAN ships brass automotive adapters free of charge — just leave a note at checkout.
• Mounting: 265mm tall in standard orientation — sized for floor-mounted installs in lockers, engine rooms and off-grid cabinets. Upright is optimal for longevity.

Bluetooth is built in. The free TITAN app (iOS and Android, 10 languages) shows everything that matters in real time:

• Live voltage, current in both amps and watts
• State of charge as a percentage and in Ah
• Individual cell voltages
• Internal temperature
• Estimated time to full or empty
• Protection trip history
• Live balancing activity

Handles multiple batteries in series or parallel and re-calculates totals automatically — whether you’ve got one 280Ah or three in parallel for a 840Ah / 10.7kWh house bank, the figures on screen match the actual pack.

TITAN backs every grade-A cell battery with a warranty that lasts the lifetime of the battery — fully transferable. The parent company has been trading continuously since 1948, so they intend to be around to honour it in 20 years’ time.

The warranty covers components against premature failure caused by manufacturing faults.

The TITAN 280Ah sits at around £720 new. Over its 10-year design life that’s ~£72 a year.

The lead-acid equivalent — two Exide AGM EP2100 in parallel to match the usable Wh — is around £1,040 with a 4-year design life, which means replacing it roughly 2.5 times over the same period. Call it £260 a year, with cascading labour each replacement.

If something fails, TITAN repairs the failed module — BMS, balance board, a single cell — rather than replace the whole battery. Lower cost, lower carbon footprint, faster turnaround. As a family of battery specialists trading since 1948, there isn’t much they haven’t already rebuilt.

• 1 × TITAN 280Ah Lithium Leisure Battery
• 1 × Terminator (for inverter communications)
• 1 × Set of M8 bolts
• 1 × User manual

Need brass SAE/automotive terminal adapters? Free on request — just leave a note at checkout.