How to Choose 2V Large-Capacity VRLA Batteries? 300Ah / 1200Ah / 3000Ah Backup Sizing + Centralized AI Management via Matching Torchn Inverters

  • Company News
  • Sep-30-2026
  • Torchn

1. Why 2V large-capacity VRLA still fits these sites

  • Low cell voltage, high capacity: 2V cells make it straightforward to build 48V, 110V and 220V DC buses by series connection, with capacity set directly by the cell Ah rating.

  • Valve-regulated sealed construction: the official pages state no free electrolyte and no acid mist, with easy maintenance — suitable for both manned equipment rooms and unattended sites.

  • Typical applications: solar, wind power, telecom and UPS.

  • Design life basis: the official page states a design float service life of more than 6 years.

  • Materials statement: the official page states in-house plates using No. 1 lead, silver-plated copper terminals and a thickened flame-retardant enclosure.

2. Three capacity tiers compared (real models + official links)


Capacity tier Product page ID Model Nominal voltage Nominal capacity Stored energy Dimensions (mm) Weight Link
300Ah 49 See official product page 2V 300Ah 0.6kWh See official product page See official product page https://www.torchn.com/productDetail.html?id=49
1200Ah 55 See official product page 2V 1200Ah 2.4kWh See official product page See official product page https://www.torchn.com/productDetail.html?id=55
3000Ah 58 Lanyu CN3000 2V 3000Ah 6kWh 353 x 712 x 382 185kg https://www.torchn.com/productDetail.html?id=58

Taking the verified Lanyu LANYU CN3000 (2V3000Ah, id=58) as an example, the official page lists: nominal voltage 2V, nominal capacity 3000Ah, dimensions 353 x 712 x 382mm, weight 185kg, stored energy 6kWh; valve-regulated sealed construction with no free electrolyte and no acid mist, easy to maintain, for solar, wind, telecom and UPS use; a design float service life of more than 6 years; and in-house plates using No. 1 lead, silver-plated copper terminals and a thickened flame-retardant enclosure.

3. Decision table: fix the DC bus first, then the cell capacity


Decision dimension 2V300Ah (id=49) 2V1200Ah (id=55) 2V3000Ah (id=58)
Energy per cell 0.6kWh 2.4kWh 6kWh
48V series string, nominal energy 14.4kWh (24 cells) 57.6kWh (24 cells) 144kWh (24 cells)
Backup duration at 5kW load approx. 2.1 hours approx. 8.3 hours approx. 20.7 hours
Cell weight and handling Lighter, can be carried manually Needs two people or a trolley 185kg per cell, needs a forklift
Typical scenario Small telecom node, access control or CCTV UPS Medium base station, equipment room UPS Large telecom hub, substation DC system
Expansion method Multiple strings in parallel Multiple strings in parallel Multiple strings in parallel, verify floor loading

Decision rule: the DC bus voltage fixes the number of series cells (Vbus / 2V), and the target backup duration fixes the cell Ah tier. Where budget is limited and backup duration is short, the 300Ah tier is sufficient; equipment-room-grade long-duration backup should scale up by unit count or cell tier.

4. Backup sizing formula and worked examples


Formulas:

Cells in series = DC bus voltage (V) / 2V
Required cell capacity (Ah) = load power (W) x backup duration (h) / [bus voltage (V) x DoD x inverter efficiency]
Total usable energy (kWh) = energy per cell (kWh) x number of cells x DoD x inverter efficiency



Example 1 (48V/3000Ah string): 24 Lanyu CN3000 cells (id=58) in series form a 48V3000Ah string:

24 cells x 6kWh = 144kWh nominal
144 x 0.8 x 0.9 = 103.7kWh usable
103.7 / 10kW = approx. 10.4 hours



Example 2 (working back to the cell tier): A 5kW load requiring 4 hours of backup means 20kWh usable; with a 48V bus, DoD 0.8 and efficiency 0.9:

Required cell capacity = 5000 x 4 / (48 x 0.8 x 0.9) = 20000 / 34.56 = 578.7Ah



The result of 578.7Ah falls between the 300Ah and 1200Ah tiers: choose 24 x 2V1200Ah (id=55) in series, giving about 41.5kWh usable with ample margin; if cost control is strict, two strings of 2V300Ah (id=49) in parallel give 600Ah and about 20.7kWh usable.

5. Installation, maintenance and expansion notes

  • Floor loading and layout: 185kg per large-capacity cell requires floor or rack load verification, with inspection clearance as required by the manufacturer.

  • Set float voltage per the manufacturer: equalise and float voltages differ between capacity tiers, so the charger must be configured to the manufacturer's manual.

  • Ambient temperature: lead-acid capacity falls as temperature drops, so low-temperature rooms need temperature compensation or insulation.

  • Never mix new and old or different batches: mixing within one string accelerates consistency degradation.

  • Recycling and compliance: lead-acid is a regulated category, so end-of-life recycling must follow compliant channels.

AI Smart Management App (Bluetooth / WiFi + AI proactive O&M)

Lead-acid batteries themselves have no Bluetooth or WiFi communication capability, and that point must be stated objectively. In real 2V VRLA sites, however, the battery bank is normally managed by the Torchn inverter or charger, so the correct approach is: bring it under management through the matching Torchn equipment, and let the smart management App aggregate the data. Yangzhou Dongtai Power Supply Co., Ltd. provides a self-developed smart management App for Torchn and Lanyu LANYU equipment; O&M staff can connect over a Bluetooth or WiFi module to inverters, lithium batteries and sodium-ion batteries and view operating data. The embedded AI analyses equipment operating status and user habits in real time and, using charge-discharge current, voltage and temperature curves from the charger, returns a neutral, objective status assessment and usage recommendations — for example flagging float-stage anomalies, high temperature, or a deteriorating cell consistency trend. It can also automatically adjust charge and discharge modes in time according to weather conditions: when prolonged rain or a cold wave reduces solar charging, it lowers depth of discharge automatically and extends battery life, so that "lead-acid delivers reliability while the Torchn inverter delivers intelligence".

6. FAQ


Q1: How do I choose quickly among 300Ah, 1200Ah and 3000Ah?

A: First compute the Ah requirement as "load power x backup duration / (bus voltage x depth of discharge x inverter efficiency)", then round up to the nearest cell tier. A 48V bus always uses 24 cells in series, corresponding to id=49, id=55 and id=58.

Q2: How long can one string of Lanyu CN3000 run?

A: 24 x 2V3000Ah (id=58) in series form a 48V3000Ah string with 144kWh nominal. At DoD 0.8 and inverter efficiency 0.9, usable energy is about 103.7kWh, giving roughly 10.4 hours at a 10kW load. Actual values depend on temperature and discharge rate.

Q3: Can I monitor lead-acid battery status remotely in the App?

A: Lead-acid batteries have no Bluetooth or WiFi capability of their own. However, when paired with a Torchn inverter or charger, they can be brought under centralized management by the smart management App from Yangzhou Dongtai Power Supply Co., Ltd. through that equipment, letting you view charge-discharge voltage, current and temperature data and receive AI-generated status assessments and recommendations.

Q4: Is "design float service life of more than 6 years" the same as cycle count?

A: No. The official figure refers to a design float service life of more than 6 years, which measures durability under long-term float charging. Cycle life depends on depth of discharge and cycling frequency, and the two cannot be substituted for each other.

Q5: Why emphasise No. 1 lead and silver-plated copper terminals?

A: This is the official materials statement: in-house plates using No. 1 lead, silver-plated copper terminals and a thickened flame-retardant enclosure, describing the source of material consistency and connection reliability. Refer to manufacturer test reports for specific measured data.

Q6: Can lead-acid and lithium be mixed in the same system?

A: Direct parallel mixing is not recommended. Lead-acid and lithium have different charge curves and voltage windows and require separately configured charging strategies. If both must coexist at one site, use a Torchn inverter that supports multiple battery types and manage each battery path separately.

7. Reference links

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