FIAMM LM 490 2 V 546 Ah OPzS Flooded Battery Cell

LM 490, listed as 7 OPzS 490, is a 2 V vented tubular-plate cell from the FIAMM LM range designed to the German DIN 40736 OPzS standard. The folder gives 546 Ah at the 10-hour rate to 1.80 volts per cell at 20 °C, in a 166 x 206 x 536 mm case with 8.3 litres of electrolyte and a typical weight of 37.6 kg.

A 20-year OPzS cell for UPS, railway and oil and gas standby

FIAMM describes the LM series as an OPzS vented range with a 20-year design life for demanding applications. A low-antimony alloy, die-cast tubular plate gives very low water consumption over life, and capacity exceeds the figure laid down in the DIN specification, which is why the folder pairs each LM type with its DIN name.

LM 490 is one of 22 types listed from LM 100 to LM 3500. It uses the same 206 mm deep jar as the smaller cells and offers a mid-point of 546 Ah that suits substation and generating-station DC systems at 110 V and 220 V.

LM series data quoted by FIAMM

• Tubular positive plates (low antimony, die-cast) with flat negative plates.
• Design life 20 years; applications named: telecommunication, industrial UPS, utilities, industry, railways, oil and gas.
• Standards listed: DIN 40736 OPzS, DIN 43539 part 5 deep discharge and IEC 60896 part 11 vented types.
• Transparent SAN container with microporous PVC separators; electrolyte specific gravity 1.24 at 20 °C.
• Design optimised for low self-discharge in storage; fully recyclable at end of life.

Technical specification

Data printed for LM 490 in the LM folder

Values from the flooded engineering manual

Neighbouring LM types in the folder table

Derived values (calculated here, not printed)

How to read LM numbering and pick a size

Under the usual DIN naming convention (general knowledge, not a FIAMM statement) the first number is the count of positive plates, so 7 OPzS 490 has seven plates at 70 Ah each. FIAMM rates the cell at 546 Ah, about 11 percent above the DIN figure, so do not use the DIN name as the capacity when sizing.

LM 420 and LM 490 share the 536 mm height; LM 600 moves to 711 mm. If the rack height limits you, check LM 490 against the two options before ordering.

Commissioning and care notes from the flooded manual

Fill delivered dry-charged cells after rack installation, wait about 3 hours and top up to the MAX line, and begin the first charge within 18 hours at 0.10 C10 until the Ah input reaches 1.6 to 1.7 times C10. Cell temperature must stay below 45 °C.

A topping-up interval is not stated in the LM folder; follow the manual, check electrolyte level regularly, use only distilled water, and keep smoking and naked flames out of the room. Provide ventilation under EN 62485-2.

Typical sites in Oman and the GCC

Substations, power stations, telecom exchanges and rail signalling use OPzS cells because they handle deep discharge and long standby. General engineering note: cell electrolyte temperature in non-air-conditioned plant rooms can pass 30 °C, which per the manual reduces life, so check the room design temperature against the 20-year rating.

Related FIAMM items

LM/S is the cyclic variant for renewable storage, SMG is the sealed gel OPzV cell in the same jar sizes, and SD-SDH and SGL-SGH are the flat-plate and Planté vented ranges.

Battery room and maintenance notes

OPzS cells are widely used in the region for long-life DC supplies in substations, oil and gas facilities, power and desalination plants, and railway and telecom systems. Flooded cells produce hydrogen during charging, so the battery room must be ventilated as required by the manual and the applicable standard, with no ignition sources near the cells. The room should be cooled, because high temperatures shorten battery life, and the charger’s float voltage and temperature compensation should be set as given in the manual.

Size the battery from the duty cycle, including any high-current periods such as switchgear tripping, with ageing and temperature margins. Check electrolyte levels, specific gravity and cell voltages at the intervals in the manual, top up only with the specified water, and recheck connection torque during routine maintenance.

Keep a record of the installation date and all readings, so trends can be seen early.

Information to send with an enquiry

• System DC voltage and duty cycle
• Required autonomy and number of cells
• Racks, connectors and accessories
• Quantity

Frequently asked questions

What does 7 OPzS 490 mean?

It is the DIN 40736 designation; by convention the 7 is the positive-plate count and 490 the nominal Ah.

What capacity does LM 490 deliver?

546 Ah at the 10-hour rate to 1.80 volts per cell at 20 °C.

What design life is stated?

20 years for the LM series.

Which standards are listed?

DIN 40736 OPzS, DIN 43539 part 5 deep discharge and IEC 60896 part 11 vented types.

How much electrolyte does it take?

8.3 litres per cell at a specific gravity of 1.24 at 20 °C.

Documents and quotation

Need LM 490? The FIAMM datasheet and user manual are attached to this listing. Seven Star LLC (independent supplier, Muscat) can quote the item and arrange supply on request; list quantity and site location in your enquiry. Verify the order code and electrical options in the documents before ordering. Other products are in the category page.