/ RESERVE POWER · NDP — NORMAL DENSITY POWER
2V NDP battery — dependable standby, honestly priced
NDP — Normal Density Power — is the standby line Microtex has built since 1984: 2V flooded tubular cells, 20 Ah to 1100 Ah, with a 10-year design life and the tin-selenium low-antimony metallurgy that keeps corrosion slow and topping-up rare. The sensible specification for power stations, substations, signalling, process industry and telecom standby where every rupee must justify itself.
2V · 20–1100 Ah — Made since 1984 — 10-year design life — Tin-selenium low-antimony tubular plates

FIG. 1 — 2V NDP CELLS · PPCP CONTAINERS
The engineering, in plain terms
Tubular positive plates in woven gauntlets carry the capacity; the tin-selenium low-antimony alloy is the quiet hero — selenium refines the grain structure of the spine so corrosion advances slowly and evenly, which is what a 10-year design life actually rests on. Cells sit in impact-resistant heat-sealed PPCP containers (SAN transparent available), with ceramic flame-arrestor vent plugs and lead-plated copper connectors rated for the duty. Specific gravity 1.200 at 27 °C; float at 2.23 V/cell; deep-discharge capable to 80% DoD. Water topping typically once in 12–15 months.
Where NDP is the right specification
Power generation and substations, railway signalling, UPS and switchgear standby, process industries, telecom, and large solar off-grid banks — anywhere the duty says “reliable standby, maintained site, sensible budget.” Where the tender is nuclear/thermal/hydro mission-critical with a 20-year expectation and transparent-container inspection clauses, step up to HDP; where it says IS 1651 workhorse, the 2V flooded range may serve at still better economy. We will tell you which — that is the point of asking engineers instead of a price list.
Questions buyers ask us
What does NDP actually stand for?
Normal Density Power — the standard-duty sibling of our HDP (High Density Power) line. Same tubular flooded construction; the grades differ in design life, materials and container class, so budgets buy exactly the endurance the duty needs.
Can you support GeM and utility tender documentation?
Yes — GTPs, discharge curves, drawings, clause-wise compliance statements and witnessed FAT are standard practice here. Send the annexure with the enquiry.
What maintenance does an NDP bank need?
A civilised amount: hold the float voltage, top up with demineralised water roughly every 12–15 months (the low-antimony alloy earns that interval), keep the room ventilated, log voltages and SG on a round. The manual is one page; following it is most of the 10 years.
Delivery and warranty?
Built to order — factory-fresh cells, typically ~60 days, crated for safe transport; standard one-year warranty on supplies. Commissioning guidance ships with the bank.