Saft Sunica.plus pocket plate nickel-cadmium, 45 to 1,110 Ah across 19 models
Saft Sunica.plus pocket plate nickel-cadmium, 45 to 1,110 Ah across 19 models is one of 7 battery systems tracked in the SecondWatt catalogue, each with specifications, lead times and indicative secondary-market pricing.
Saft Sunica.plus dossier: pocket plate nickel-cadmium from 45 to 1,110 Ah, a 20-year design life, and why it is a solar rather than a switchgear product.
Why it matters
This is the only chemistry in the catalogue whose service life is quoted in decades, which inverts the usual used-equipment logic. A 10-year-old nickel-cadmium string may be half way through its life where a 10-year-old lead-acid string is finished, so calendar age alone is a weak signal and the electrolyte and capacity test records carry the assessment instead.
Who buys it
Off-grid solar, telecom and remote infrastructure operators who need a battery that survives temperature extremes and deep discharge without permanent damage, and who can accept a maintenance regime. The economics work where a lead-acid string would need replacing three times across the same service life.
Role in the data center
None directly. This is an off-grid and solar product; the switchgear and substation control battery in Saft's range is Uptimax, and that is the record a data center or substation buyer needs.
Key specifications
| Cell voltage | 1.2 nominal, pocket plate V |
|---|---|
| Capacity range | 45 to 1,110 across 19 models Ah |
| Capacity at the C120 rate | 43 to 1,024 Ah |
| Capacity at the C5 rate | 15.95 to 352 Ah |
| Design life | 20, at about 8,000 cycles to 15% depth of discharge years |
| Charge voltage, 9-cell 12 V system | 13.5 to 14.4 depending on depth of discharge V |
| Operating temperature | minus 20 to 50 standard, minus 50 to 70 tolerated degrees C |
| Low temperature capacity | more than 80% on a 120-hour discharge at minus 40 degrees C |
| Water topping interval | more than 4 years, automated filling optional from 185 Ah |
| Dimensions and weight, SUN 45 | 195 x 113 x 137 mm at 3.2 kg |
| Weight, SUN 1110 | 46.0 kg |
| Standards cited | IEC 62259 and EN 50272-2, with IP2 shock protection |
| Published price | none located for any Saft nickel-cadmium range |
Technical summary
Cell voltage: 1.2 V nominal, pocket plate construction with internal gas recombination Capacity range: 45 to 1,110 Ah across 19 models; 43 to 1,024 Ah at the C120 rate and 15.95 to 352 at C5 Design life: 20 years, with about 8,000 cycles at 15% depth of discharge Charge voltage: 13.5 to 14.4 V on a 9-cell 12 V system, scaling to 54 to 57.6 V on 36 cells Operating temperature: minus 20 to 50 degrees C standard, tolerating minus 50 to 70 at the extremes Low temperature performance: more than 80% of capacity on a 120-hour discharge at minus 40 degrees C High temperature performance: about 20% life loss at 30 degrees C against a claimed 50% for lead-acid Water topping: more than 4 years between top-ups, with automated filling optional from 185 Ah upward Dimensions and weight: SUN 45 at 195 by 113 by 137 mm and 3.2 kg; SUN 1110 at 46.0 kg Standards: IEC 62259 for pocket plate nickel-cadmium and EN 50272-2 for installation safety
Configurations and options
Blocks in series to the system voltage, with an optional integral automated water filling system on cells from 185 to 1,110 Ah that removes most of the maintenance objection. A higher-density electrolyte formulation is available for service below minus 20 degrees C.
Compatibility and dependencies
A lead-acid charger cannot be reused, because nickel-cadmium float and boost voltages are different and the recommended charge window varies with depth of discharge. The standard cited on the datasheet is IEC 62259 for pocket plate construction rather than IEC 60623, and IEEE 1106 and 1115 govern United States maintenance and sizing without being named on the Saft document.
Pricing and availability
Trend: flat Lead time, new: Quote only; no published lead time located.
Lifecycle and maintenance
Vented nickel-cadmium batteries are the long-life option in stationary power, routinely quoted in decades rather than years, and they tolerate deep discharge, freezing and abuse that would destroy a lead-acid string. The trade is maintenance: the cells are vented, they lose water through gassing and need topping with purified water, and the electrolyte carbonates over years of service so that renewal rather than replacement is the mid-life intervention. IEEE 1106 governs installation, maintenance and testing, with the same 80% of rated capacity replacement trigger used elsewhere in stationary practice, and IEEE 1115 governs sizing. At a NERC-registered facility the interval obligations are a 6-year capacity test alongside 4-month voltage, electrolyte and ground checks.
Common failure points
- Electrolyte loss — Vented cells lose water through gassing and capacity falls if topping is neglected
- Carbonation — Electrolyte absorbs carbon dioxide over years, raising resistance and cutting capacity
- Plate degradation — Pocket plate active material degrades slowly and capacity falls below the 80% replacement trigger
- Intercell connections — Corroded or loose links raise string resistance and produce local heating
- Charger mismatch — A lead-acid charger applied to nickel-cadmium will not reach the correct float or boost voltage
- Cadmium disposal — End-of-life handling is regulated and a buyer can be left holding cells no recycler will take
Inspection checklist
Electrolyte level — pocket plate cells are vented and need topping, so check the level marks on 100% of cells rather than a sample Topping interval — confirm purified water was used and record the interval, because 1 neglected year accelerates carbonation Carbonation — electrolyte absorbs carbon dioxide across 20 years of service and loses capacity; ask whether it has ever been renewed Capacity test record — IEEE 1106 governs vented nickel-cadmium testing, with 80% of rated capacity as the replacement trigger Test interval compliance — a NERC-registered site owes nickel-cadmium a 6-year capacity test and 4-month voltage, electrolyte and ground checks Cell count and string voltage — confirm the string matches the 125 or 250 VDC control bus it was built for Plate condition — pocket plate construction tolerates deep discharge and freezing far better than lead-acid, but 1 degraded plate set is terminal Age against design life — these batteries routinely run 20 years or more, so calendar age alone is a weak signal of remaining value Sizing basis — IEEE 1115 governs nickel-cadmium sizing, and a string sized for one duty cycle will not serve another Cadmium handling — cadmium is a regulated toxic metal under the 40 CFR 273 universal waste rules, so confirm the recycler will accept the cells Regulatory exposure — EU battery rules restricted cadmium in portable batteries while exempting industrial ones, and whether the 2023 regulation preserved that exemption is unresolved Terminal and intercell links — inspect for corrosion and confirm torque against the manufacturer's published value Charger compatibility — nickel-cadmium float and boost voltages differ from lead-acid, so a lead-acid charger cannot be reused Application match — Sunica.plus is built for solar and off-grid duty rather than switchgear tripping, so confirm the duty before reusing a string Freight and handling — vented alkaline cells ship filled under UN2795, so weight and spill containment govern transport
Regional notes
French manufacturer under TotalEnergies ownership since 2016, with documentation dated 2023 and 2024 across the nickel-cadmium ranges.