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| SERVICE | DELIVERY PRICE | DELIVERY TIME |
|---|---|---|
| Standard Delivery | £19.95 | 7 to 10 working days |
| SERVICE | DELIVERY PRICE | DELIVERY TIME |
|---|---|---|
| Standard Delivery | £19.95 | 7 to 10 working days |
| SERVICE | DELIVERY PRICE | DELIVERY TIME |
|---|---|---|
| Standard Delivery | £7.99 | 3 to 5 working days |
| SERVICE | DELIVERY PRICE | DELIVERY TIME |
|---|---|---|
| Standard Delivery | £7.99 | 5 to 7 working days |
| SERVICE | DELIVERY PRICE | DELIVERY TIME |
|---|---|---|
| Standard Delivery | £7.99 | 7 to 10 working days |
Older commercial vehicles, agricultural equipment and vintage machinery often rely on 6-volt electrical systems that modern battery ranges simply do not accommodate. The Numax 521/21 is a dedicated 6V lead-acid battery engineered to meet that requirement, supplying 146Ah of capacity at the C20 rate for dependable starting and standby performance across heritage and classic commercial applications.
Manufactured under the Numax Commercial range, this battery is built to the exacting quality standards that define the Numax Classic CV product group. Numax batteries are constructed to cope with the sustained electrical demands placed on commercial and vintage vehicles, where consistent delivery of stored energy is critical to reliable operation over an extended service life.
The 521/21 measures 263mm (L) × 172mm (W) × 217mm (H including terminal) and weighs 14kg. It is fitted with a Type 1 terminal post and carries polarity code 0, with a B00 hold-down configuration. No direct cross-reference numbers are listed for this SKU; buyers should verify fitment against their vehicle's original battery specification. Compatibility with start-stop systems is not confirmed – refer to the product label before installation.
This battery is available across a range of related SKUs within the Numax Classic CV series, including S629, 612, 620, 622, 623, 624, 625, 629, 629UR and 632, allowing fitment across multiple vintage and heritage commercial platforms." The 521/21 is supplied with a 1-year warranty covering defects in materials and manufacture under normal operating conditions. "Delivery: pallet shipment, typically 3–5 working days within UK mainland. Contact PartsForMachines for delivery quote. 30-day returns.
Quality, durability and performance sum up the NUMAX range of batteries. NUMAX batteries are built to the very highest specification to cope with today’s automotive electrical demands. The NUMAX automotive range has a battery to suit every application whilst providing premium quality and value. That’s why people trust the NUMAX battery brand to give them the performance they need no matter how harsh the conditions.
Key Feature:Developed by Numax as a 6.0 1 battery, offering stable energy output, dependable starting power, and compatibility across general automotive and light commercial applications.
Uses:PartsForMachines is a premier e-commerce platform, founded in 2019 in Warwickshire, UK, specialising in aftermarket parts and services for construction, agriculture, and industrial machinery. We offer an extensive catalogue of over 500,000 products. Standard delivery: 1–3 working days within UK mainland. We are proud to be an authorised distributor, giving customers extra confidence when purchasing genuine products from us. In addition, we provide a 30-day return policy for eligible items.
Fitment Warning:You must check your current battery against the specifications of this battery before ordering to ensure that this is the correct battery for your vehicle. Check battery technology, dimensions, terminal type, polarity, capacity (AH) and cranking performance (CCA). We cannot guarantee correct fitment under any circumstances.
| Brand | Numax Batteries |
|---|---|
| Voltage | 6V |
| Capacity AH (C20) | 146Ah |
| Cold Cranking Amps (EN) | |
| L × W × H | 263mm × 172mm × 217mm |
| Warranty period | 1 Year |
| Weight (Kg) | 14 |
| Capacity AH (C5) | |
| Capacity AH (C10) | |
| Capacity AH (C100) | |
| Marine Cranking Amps (MCA) | |
| Watt-Hours (WH) | |
| Length (mm) | 263 |
| Width (mm) | 172 |
| Height Inc. Terminal (mm) | 217 |
| Terminal Placement | 0 |
| Terminal Type | 1 |
| Hold Down | B00 |
| Case Size | |
| ETN Number | |
| TTNR |
| Engine Parts | Product Number | Product Name | Recommended Units | Product Price |
|---|
Expert Guidelines for Preserving Your Heavy Equipment Battery Heavy machinery, including forklifts, bulldozers, and excavators, relies on robust batteries to minimize downtime and maximize operational availability. These batteries must endure even more challenging conditions than typical automotive batteries. Moreover,...
Standard Delivery: £7.99
Delivery Estimate: 3 to 5 working days
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| Technical Specification | ||||
|---|---|---|---|---|
| PRODUCT NUMBER | YBX1612 | YBX1630 | YBX1655 | YBX1657 |
| Voltage | 12 | 12 | 12 | 12 |
| Capacity (AH) | 143 | 143 | 126 | 142 |
| Hold Down | N | B3 | N | N |
| Cold Cranking Amps (EN1) | 900 | 900 | 750 | 850 |
| Terminal Type | T1 | T1 | T1 | T1 |
| Cell Layout | 3 | 3 | 0 | 0 |
| Length | 513 | 513 | 347 | 345 |
| Width | 189 | 189 | 174 | 175 |
| Height | 223 | 223 | 285 | 275 |
| Show More | ||||
A. The Numax 521/21 operates at 6 volts, making it suitable for vintage commercial vehicles, heritage machinery and agricultural equipment that retain a 6V electrical system.
A. The 521/21 provides a rated capacity of 146Ah measured at the C20 rate. No C5, C10 or C100 ratings are specified for this product.
A. The battery measures 263mm in length, 172mm in width and 217mm in height including the terminal. It weighs 14kg. Always verify that these dimensions are compatible with your battery tray before ordering.
A. The 521/21 is fitted with a Type 1 terminal post and carries polarity code 0. The hold-down configuration is B00. Confirm that your vehicle's battery clamps and cabling are compatible with these specifications prior to installation.
A. Start-stop compatibility for the 521/21 is not confirmed. Please refer to the product label supplied with the battery before installing it in any vehicle equipped with a start-stop system.
A. No cross-reference numbers are listed for the 521/21 SKU. Buyers should verify fitment using the battery's dimensions, voltage, capacity and terminal specification against their vehicle's original equipment requirements.
A. Related variants within the Numax Classic CV series include S629, 612, 620, 622, 623, 624, 625, 629, 629UR and 632. Contact PartsForMachines to confirm which SKU is correct for your specific application.
A. The 521/21 is covered by a 1-year manufacturer's warranty against defects in materials and workmanship under normal operating and charging conditions. Warranty claims should be raised through PartsForMachines.
A. Yes. The 521/21 is designed specifically for applications requiring a 6V battery, including vintage commercial vehicles, classic agricultural equipment and heritage machinery where modern 12V batteries are not appropriate.
A. The 521/21 is dispatched on a pallet and typically arrives within 3–5 working days to UK mainland addresses. Delivery costs vary; contact PartsForMachines for a quote before placing your order. A 30-day returns policy applies to this product.
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