6-EVF-50 12V50Ah AGM VRLA Battery for Solar Street Lighting

Answer First

The 6-EVF-50 12V50Ah AGM VRLA block is the smallest sealed block in the CHISEN 6-EVF AGM product line, and every number that decides whether it belongs on a solar lighting pole or in an off-grid cabinet is already fixed by the manufacturer: 12 V nominal, 50 Ah at the C3 rate, 230 × 140 × 180 mm, 15.25 ± 0.2 kg, an M6 terminal, a 13.5 V float setpoint, a 14.1 V equalising setpoint, a 10.0 A maximum charge current, a 1.75 V/cell discharge cut-off, self-discharge of ≤3 %/month at 25 °C, a working range of −15…50 °C and a published design life of 2–5 years. The complete data sheet is on the 6-EVF-50 model page, and every figure in this article traces back to that page or to arithmetic performed on those figures.

Arithmetically, one 6-EVF-50 12V50Ah block stores 600 Wh (12 V × 50 Ah, Arithmetic) and delivers 16.7 A at the three-hour discharge rate (50 Ah ÷ 3 h, Arithmetic). Two blocks in series give a 24 V solar bus holding 1,200 Wh (24 V × 50 Ah, Arithmetic), floating at 27.0 V (2 × 13.5 V, Arithmetic) and weighing 30.5 kg (2 × 15.25 kg, Arithmetic). Four blocks in series give a 48 V bus holding 2,400 Wh (48 V × 50 Ah, Arithmetic) and weighing 61 kg (4 × 15.25 kg, Arithmetic); a charger for that string must be rated at least 40 A (4 × 10.0 A, Arithmetic) to bring the bank back to full charge after a dark winter week.

Two figures deserve attention before any purchase order is raised. First, the published design life of this VRLA product line is 2–5 years, not the multi-decade float life of CHISEN’s flooded OPzS2 or gel OPzV2 tubular products; a 6-EVF-50 12V50Ah bank on a solar pole must be budgeted as a consumable with a scheduled replacement. Second, the self-discharge of ≤3 %/month at 25 °C still costs a 48 V string of four blocks 6.0 Ah per month (4 × 1.5 Ah, Arithmetic), and a cabinet idle through a long cloudy season loses more energy that way than many installers expect.

Key Takeaways

• Published specification, not a guess. The 6-EVF-50 12V50Ah is a 12 V, 50 Ah, C3-rate AGM VRLA block measuring 230 × 140 × 180 mm and weighing 15.25 ± 0.2 kg with an M6 terminal (Model page).
• 600 Wh per block, 1,200 Wh for a 24 V pair. The arithmetic is simple: 12 V × 50 Ah = 600 Wh per block, so two blocks in series form the standard 24 V lighting bus (Arithmetic).
• Float charging at 13.5 V per block. That is 2.25 V per cell (Arithmetic), the standard VRLA float target that holds the cell on the absorption plateau without driving water loss (Model page).
• Equalising at 14.1 V per block, or 2.35 V per cell. Equalising is a controlled procedure in solar service, applied block by block rather than across a partially wired bank (Model page).
• Size the charger from the published 10.0 A maximum charge current. A 24 V pair needs at least 20 A, a 48 V string at least 40 A, and a 48 V bank of eight blocks at least 80 A (Arithmetic).
• Design life is 2–5 years for this VRLA product line. Long-life tubular OPzS2 and OPzV2 products are a separate range with separate physics; budget the 12 V AGM lighting bank as a five-year replacement item (Model page).

§1 — 6-EVF-50 12V50Ah Published Specifications

The table below reproduces the specification block exactly as published for the 6-EVF-50 12V50Ah on the CHISEN model page. No value has been rounded, converted or derived. Parameters the source does not publish are listed explicitly rather than estimated.

The final voltage table, the internal resistance figure and the temperature-compensation coefficient are the parameters a solar integrator asks for first, and for the 6-EVF-50 they must be requested from the factory rather than assumed. The charging profile itself can be derived from the published setpoints — 13.5 V float, 14.1 V equalise, 10.0 A maximum charge current — but the compensation slope for a cabinet in direct summer sun is a factory item.

§2 — Float, Equalising and Charge Acceptance in Solar Duty

A solar lighting installation has two distinct operating modes, and the 6-EVF-50 12V50Ah is rated for both. In the first, the bank sits on float charge through the day while the controller passes surplus panel current into it; in the second, the bank delivers the night’s load at a moderate discharge rate while the panels are idle.

Float duty sets the resting voltage at 13.5 V per block, which is 2.25 V per cell (Arithmetic) — the standard VRLA float target that keeps the cell on the absorption plateau without boiling away electrolyte. Equalising at 14.1 V per block (2.35 V per cell, Arithmetic) is a controlled corrective procedure, not a permanent setpoint: in solar service it is applied after deep discharge or when cells drift apart in voltage, and it is done block by block — never across a partially wired bank, where the lowest cell would absorb the whole voltage difference.

The published maximum charge current of 10.0 A per block gives a ceiling of 0.2 C10 (10.0 A ÷ 50 Ah, Arithmetic). That is the number to match against the controller output: a controller rated for more than 20 A on a 24 V pair will push the block beyond its published maximum charge current, which accelerates water loss and shortens service life. A controller rated for less leaves the bank slow to recover after a cloudy week.

Standby losses matter more in solar duty than in a mains-fed cabinet. At ≤3 %/month at 25 °C, one block loses 1.5 Ah per month (Arithmetic); a 24 V pair loses 3.0 Ah per month and a 48 V string of four blocks loses 6.0 Ah per month (Arithmetic). Against a 1,200 Wh 24 V pair, 3.0 Ah is 36 Wh, roughly 3 % of stored energy — a meaningful slice of a 50 W load’s monthly budget when the panel days are short.

The working temperature envelope of −15…50 °C (Model page) covers most lighting sites, but it is an ambient figure: a sealed cabinet in direct sun runs warmer than the air, and a sealed AGM block sheds heat less freely than a flooded cell. Enclosure thermal management is the integrator’s decision; the published working range is the only temperature authority in this data sheet.

§3 — String Sizing: 24 V, 48 V and Parallel Banks for Lighting and Off-Grid Loads

Most single-lamp solar systems in the field run on a 24 V bus because that is what common charge controllers and LED drivers expect. A 48 V bus is the choice when the site also carries signage, a camera, a communications radio or a small off-grid load that must run through a deep-winter storm.

Two rules govern how those numbers are combined. First, every block in a series string carries the same current, so the charger requirement follows the number of series blocks, not the total block count: a 48 V 2P4S bank still charges at 40 A per series string, and the controller must be rated for 80 A across two parallel strings. Second, mass and energy are proportional, so a 48 V 4P4S bank of sixteen blocks delivers 9,600 Wh (Arithmetic) but weighs 244 kg (Arithmetic) and needs a rated enclosure and a structural check for the cabinet or the pole base.

The discharge floor follows from the published 1.75 V/cell cut-off: 10.5 V per block (6 × 1.75 V, Arithmetic), so 21.0 V for a 24 V pair and 42.0 V for a 48 V string (Arithmetic). A controller with a low-voltage disconnect above those points cuts the lamp before the battery is exhausted; a disconnect below them pulls the block into a region where capacity is not recoverable at a useful rate.

For integrators who need a higher-capacity single block in the same sealed range, the 6-EVF-60 12V60Ah sits one step up, and the 6-EVF-100 12V100Ah doubles the capacity of the 6-EVF-50 12V50Ah (100 Ah ÷ 50 Ah = 2.0, Arithmetic) for 2.07 times the mass (31.5 kg ÷ 15.25 kg, Arithmetic). The full ladder from 50 Ah to 150 Ah sits on the CHISEN EVF product page.

§4 — The Nightly Energy Budget: Depth of Discharge, Cycle Life and the Acceptance Test

The published cycle life of the 6-EVF-50 12V50Ah is 350–600 cycles at 50–80 % depth of discharge (Model page). That range is the single most useful planning figure for a solar lighting project, because a solar pole that is sized to run its lamp for two nights of autonomy is effectively operating at deep discharge, and a pole sized for one night of autonomy is operating near the shallow end of that range.

A worked example, with the assumptions stated: a 50 W LED fixture switched on for 10 hours each night consumes 500 Wh per night (50 W × 10 h, Arithmetic). A 24 V pair of 6-EVF-50 12V50Ah blocks holds 1,200 Wh (Arithmetic), so at a 50 % depth of discharge the usable energy is 600 Wh (1,200 Wh × 50 %, Arithmetic) — roughly one night’s load, with the second night’s requirement covered only if the following day is fully sunny. That is a deliberate design choice: it keeps the working depth of discharge inside the published 50–80 % band instead of running the bank to an 80 % discharge every night.

The acceptance test on delivery should follow the same numbers rather than a generic capacity check. For a 24 V pair the expected float bus is 27.0 V (2 × 13.5 V, Arithmetic) and the equalising bus is 28.2 V (2 × 14.1 V, Arithmetic). After a controlled discharge to the 21.0 V floor (2 × 10.5 V, Arithmetic), the pair should return to the 27.0 V float level within the recharge window allowed by the 20 A minimum charger (Arithmetic). Checking individual blocks after the equalising step reveals cell imbalance that a bus-voltage measurement hides, and imbalance is what shortens a lighting bank’s life.

Weight is the parameter most often overlooked at specification stage. A 24 V pair is 30.5 kg and a 48 V string of four is 61 kg (Arithmetic) — on a pole that is a structural and wind-loading question, in a ground cabinet a floor-rating and shelving question. Both figures come from the published 15.25 ± 0.2 kg per block and should be checked against the mounting design before the order is released.

§5 — Where the 6-EVF-50 Sits in the 12 V AGM Range

The 6-EVF AGM series shares one charging profile across its whole capacity ladder: 13.5 V float, 14.1 V equalise, 1.75 V/cell cut-off, self-discharge of ≤3 %/month at 25 °C, a working range of −15…50 °C and a design life of 2–5 years (Model page). What changes from one model to the next is capacity, footprint, mass and maximum charge current.

For installations that need slightly more capacity than 50 Ah in the same sealed range, the neighbouring models are the 6-EVF-60 at 60 Ah and 18.8 ± 0.2 kg and the 6-EVF-80 at 80 Ah and 25.7 ± 0.2 kg (Model page). Neither brings a different charging regime, so a controller set up for the 6-EVF-50 12V50Ah serves the whole series.

Where the 6-DMF blocks overlap in capacity, the choice comes down to application. The 6-DMF-52 12V52Ah is a 12 V, 52 Ah, C3-rate block of 224 × 135 × 175 mm and 13.7 ± 0.2 kg with a 10.4 A maximum charge current, while the 6-DMF-45 is 12 V, 45 Ah, 224 × 121 × 175 mm and 12.3 ± 0.2 kg with a 9.0 A maximum charge current (Model page). Both share the 13.5 V float, 14.1 V equalise, 1.75 V/cell cut-off and 2–5 year design life of the wider 12 V VRLA range.

One purchasing caution applies to the DMF comparison rows: the model pages for 6-DMF-52 and 6-DMF-45 also list alternative weight variants in their horizontal comparison tables (14.5 kg and 13.1 kg respectively). Only the specification-table weight is used here, and pack builders must confirm the delivered variant on the order acknowledgement. The AGM series range and the VRLA/GFM overview on the CHISEN VRLA pages document the same product line from the manufacturer’s side.

§6 — The Trust: What to Ask the Supplier Before the Purchase Order

A lighting project is bought once and maintained for years, so the questions asked at quotation stage decide the service life of the installed bank. The first is the datasheet: ask for the specification sheet behind the model number you are buying — float voltage, equalising voltage, maximum charge current, cut-off voltage, working temperature range and design life — and check each line against the published values on the 6-EVF-50 model page. The second is the factory data this page does not publish: internal resistance, the temperature-compensation slope, the charge termination criterion and the final-voltage table, requested in writing rather than assumed from a generic VRLA chart.

Third, ask how the blocks are packed and shipped — a 15.25 ± 0.2 kg block dropped in transit arrives in a condition that matters more than any datasheet line. Fourth, ask what the replacement commitment is for a 2–5 year design life product in solar duty: the published life assumes the float and equalise setpoints above, the published temperature range and the published depth of discharge band. A supplier quoting a long service life without those three conditions attached is quoting a different product.

On the manufacturer side, CHISEN Battery operates 8 production bases with an annual capacity of 70 million kVAh, holds CE, ISO 9001, ISO 14001, UL and IEC certification, and builds the flooded tubular OPzS2 line, the gel tubular OPzV2 line, the 12 V VRLA range (6-DZF, 6-DMF, 6-EVF), 6 V and 8 V EVF blocks, solar storage systems and lithium storage systems (Model page). The profile is published at www.chisen.cn/en/about.html — it tells an integrator that a replacement block three years into the project comes from the same specification set rather than an unknown second source.

FAQ

Q1: What are the nominal voltage and capacity of the 6-EVF-50 12V50Ah? 12 V nominal and 50 Ah at the C3 rate (Model page).

Q2: How much energy does a single block store? 600 Wh, from 12 V × 50 Ah (Arithmetic).

Q3: What discharge current applies at the published C3 rate? 16.7 A, since 50 Ah ÷ 3 h = 16.7 A (Model page).

Q4: What float and equalising voltages should the charger be set to? 13.5 V float and 14.1 V equalise per block, which is 2.25 V and 2.35 V per cell (Model page).

Q5: How many blocks make a 24 V solar lighting bank, and what does it hold? Two blocks in series, holding 24 V × 50 Ah = 1,200 Wh nominal (Arithmetic).

Q6: What is the float and equalise voltage of that 24 V bank? 27.0 V float (2 × 13.5 V) and 28.2 V equalise (2 × 14.1 V) (Arithmetic).

Q7: What charger current is required for a 24 V pair and for a 48 V string? At least 20 A for the pair (2 × 10.0 A) and at least 40 A for a 48 V string of four (4 × 10.0 A), matching the published 10.0 A maximum charge current per block (Model page).

Q8: At what voltage should the discharge be stopped? At 1.75 V per cell, which is 10.5 V per block (6 × 1.75 V), 21.0 V on a 24 V pair and 42.0 V on a 48 V string (Model page).

Q9: How much energy does a 48 V string lose to self-discharge each month? 6.0 Ah per month, from 3 % × 50 Ah = 1.5 Ah per block and 4 × 1.5 Ah for the string (Arithmetic).

Q10: How long is the design life of this battery? 2–5 years for the 12 V VRLA product line, with a published cycle life of 350–600 cycles at 50–80 % depth of discharge (Model page).

Expert Summary

The 6-EVF-50 12V50Ah is a 12 V, 50 Ah C3 AGM VRLA block, 230 × 140 × 180 mm, 15.25 ± 0.2 kg, M6 terminal, floating at 13.5 V and equalising at 14.1 V, rated 10.0 A maximum charge current, cut-off 1.75 V/cell, self-discharge ≤3 %/month at 25 °C, working range −15…50 °C, cycle life 350–600 cycles at 50–80 % DoD and a 2–5 year design life (Model page). In service that means 600 Wh per block (12 V × 50 Ah, Arithmetic), a 16.7 A C3 discharge current (50 Ah ÷ 3 h, Arithmetic), a 10.5 V block floor (6 × 1.75 V, Arithmetic), a 24 V pair at 1,200 Wh, 27.0 V float, 28.2 V equalise, 30.5 kg and a 20 A charger (Arithmetic), a 48 V string of four at 2,400 Wh, 54.0 V float, 56.4 V equalise, 61 kg and a 40 A charger (Arithmetic), a 48 V bank of eight blocks at 4,800 Wh, 122 kg and an 80 A charger (Arithmetic), a 48 V bank of sixteen blocks at 9,600 Wh and 244 kg (Arithmetic), a 21.0 V floor on 24 V and 42.0 V on 48 V (Arithmetic), a standby loss of 6.0 Ah per month on a four-block 48 V string (4 × 1.5 Ah, Arithmetic), and a charge ceiling of 0.2 C10 (10.0 A ÷ 50 Ah, Arithmetic). The float setpoint is 2.25 V per cell and equalising 2.35 V per cell (Arithmetic); the whole 12 V range shares one charging profile, one cut-off, one self-discharge figure and one 2–5 year design life, while multi-decade float life belongs to the separate OPzS2 and OPzV2 tubular product lines rather than to this VRLA block.

Contact CHISEN — 24-Hour Response

CHISEN Battery replies to technical and commercial enquiries within 24 hours, every day of the week. Send specification requests, project drawings, controller setpoint questions and delivery schedules to sales@chisen.cn; export desk correspondence also goes to jack@chisen.cn. For immediate discussion, the WhatsApp line is +86 131 6622 6999. The full company profile, product documentation and factory capability statements are published at www.chisen.cn, and the 6-EVF-50 12V50Ah model page with its complete specification block sits at https://www.chisen.cn/en/6-EVF-50/12V50Ah.html.

CHISEN Battery Team

Engineering and export team at CHISEN Battery, Hangzhou, China. Lead-acid and lithium battery manufacturer, ISO 9001 / CE / UL certified, exporting to 50+ countries.

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