Looking for 24V rack mount battery to bypass permitting

Been down this rabbit hole myself when setting up the boat install. The rack-mount form factor is genuinely useful for avoiding the "battery room" classification some surveyors go after.

Few options worth looking at:

• Fogstar Drift 24V — solid value, proper LiFePO4, UK-based support
• Pylontech US3000C — pairs nicely with Victron kit, widely used in domestic installs
• EG4 LL-S — if you're importing, decent spec for the price

The key thing with rack units is they're typically self-contained with integrated BMS, which is what makes them easier to argue as "appliances" rather than custom battery banks in some permitting conversations. Obviously worth checking your specific regs — building control vs. marine surveyor vs. DVSA all approach it differently.

What's the actual install context? Narrowboat, static, motorhome? Makes a big difference to which route makes sense. Some surveyors won't care either way, others will want full documentation regardless of form factor.

Also worth knowing — the Pylontech units communicate natively over CAN with Victron's DVCC system, which tidies up the whole setup considerably if you're running a Multiplus or Quattro.

What's everyone else using for rack installs?

@CaddyProject interesting angle — never thought about the surveyor classification side of things until I was speccing out the shepherd's hut build and someone flagged it.

One thing worth adding to your list: the Fogstar Drift cells in a proper rack enclosure sit really cleanly in that space. Not plug-and-play rack mount out the box, but with the right DIN rail BMS setup they look genuinely "industrial" rather than "battery room."

For my EV charging side I needed something that read as infrastructure rather than storage — subtle difference but surveyors and DNO inspectors seem to respond differently to the aesthetics of it. Sounds daft but it genuinely matters.

Anyone gone down the Pylontech US3000 route for this? Curious whether the official rack form factor smoothed things over with assessors or whether the labelling caused its own headaches.

Rack mount batteries — the suits-and-briefcase version of LiFePO4. Suddenly it's "server infrastructure" not "that sketchy battery cupboard."

Fogstar do a 24V rack unit worth a look, and Victron's lithium range plays nicely in 19" enclosures if you're building around a Multiplus anyway

@CaddyProject @BrianBrown Ha, Brian's not wrong about the optics shift — though I'd pump the brakes slightly on framing it primarily as a permitting workaround. Surveyors aren't daft, and if they smell evasion rather than genuine spec compliance you could end up in worse water than you started.

That said, the rack-mount form factor does have legitimate advantages beyond aesthetics — better thermal management, easier cell replacement, cleaner cabling runs in confined spaces. For a boat install specifically the physical restraint mounting points are often more engineered than a standalone unit.

What's your actual AH requirement and discharge rate? That narrows the field considerably. Pylontech and EG4 both do sensible 24V rack options but they're not identical in how the BMS communicates, which matters if you're tying into a Victron or similar setup.

@BatteryDoug makes a fair point worth expanding — "bypassing permitting" is doing a lot of heavy lifting in this thread title and I'd be careful how literally anyone takes that framing.

That said, the practical rack-mount conversation is legitimate. On my own setup I went Pylontech US3000C — solid comms with Victron kit, proper BMS, and yes, the form factor genuinely does read differently to surveyors/insurers than a pile of cells in a box.

For 24V specifically, you're usually stacking modules, so check your BMS handles that cleanly. Fogstar don't do rack-mount yet AFAIK but their cells are decent if you're going DIY route instead.

Main thing: whatever classification benefit you get from the form factor disappears fast if the install itself is dodgy. Surveyors aren't daft.