Welded steel base frame of a container module
09 / 10
Energy & CleantechOffer & tender2026

Battery storage technology container

2,000 kg/m²
floor standard
5,000 kg
point load per rack-foot pair
260 µm
coating in three layers
200
units/year target
44 %
of available capacity at that volume

The brief

A global electronics manufacturer needed technology containers for battery energy storage systems in 20, 40 and 45 ft, at a volume approaching 200 units a year, with no drawings available yet and a request that Tanax propose the technical execution rather than wait for a specification.

What was built

What was proposed

  • New one-way ISO 1CCC / 1AAA high cube base, CSC re-inspected with a new plate
  • 6,058 / 12,192 / 13,716 × 2,438 × 2,896 mm
  • Floor: C 180 × 70 × 5 cross-members at ≤ 300 mm pitch, 6 mm S355 deck welded tight, no plywood, forming a liquid-tight tray
  • 2,000 kg/m² distributed, 5,000 kg per pair of rack feet, with local reinforcement
  • 100 mm mineral wool, Euroclass A1, λ ≈ 0.035 W/m·K; PIR explicitly not recommended
  • 0.8 mm galvanised internal lining on a supporting grid
  • Blast Sa 2.5, then Zn-epoxy 80 + epoxy MIO 120 + PU 60 = 260 µm, ISO 12944 C4-H / C5-M
  • 2 (20 ft) or 4 (40 / 45 ft) framed and hooded HVAC openings
  • HV/LV cable transit plate with sealed glands
  • Explosion relief panels per EN 14994 / NFPA 68, in the base price
  • Insulated personnel door with anti-panic hardware, earthing points, data plate, CSC plate, inspection protocol

Engineering decisions

What cost money, changed the design, or both

  1. 01

    Replace the floor, do not reinforce it.

    A standard container floor is plywood on cross-members at roughly 460 mm centres. For a 6 MWh rack assembly weighing 40-50 tonnes in a 20 ft footprint, that is not a starting point. Cross-members go to ≤ 300 mm and the deck becomes 6 mm welded plate. The second benefit is free: the deck is liquid-tight, so a coolant leak or suppression discharge is contained.

  2. 02

    Say what you do not know.

    Tanax had not built a battery container before and said so in the first line of the offer, then set out precisely which three decisions differ from its normal work: floor loading, coating class and fire concept. A buyer comparing offers can verify that. A claim of prior experience does not survive a factory visit.

  3. 03

    Refuse PIR, in writing.

    PIR has the better lambda. It is combustible. In an enclosure full of stored energy the Euroclass A1 mineral wool is the safety case, and the offer says PIR is available only on request if a thermal target genuinely binds.

  4. 04

    Price bottom-up and publish the capacity consequence.

    Material at purchase cost, plus co-operation, plus direct hours at a fully absorbed overhead rate, not a catalogue estimate. And the offer states openly that 200 units a year in 20 ft form consumes roughly 44 % of available production capacity, and that a fixed price at that volume should carry a steel indexation clause because material is about 39 % of the cost.

Gallery

Photographs of the actual work

  • Base frames under fabrication
  • Cross-member and floor slot detail
  • Floor structure, second view
  • Welded steel base frame

Delivery

How it got there and got accepted

Indicative offer issued with a proposed ramp: prototype 10-12 weeks, then 4-6 units a month in months 1-3, 8-12 in months 4-8, and 17 a month from month 9, 200 a year.

Options priced explicitly: non-passthrough −€1,450 · no explosion relief −€990 · standard height instead of high cube −€165 · 3,000 kg/m² floor +€1,800.

Outcome

What was delivered, what it proved

A complete, defensible technical proposal produced without a customer drawing, benchmarked against a published Nordic armed forces framework ceiling of €80,000 for an insulated 20 ft container with no equipment, at well under half that price with substantially more content.

Send us the specification. A drawing, a tender annex, or three sentences.

You will get a written review of it inside a week, whether or not you buy anything.