The Sunstone WH2 Parallel Weld Head: Consistent, Repeatable Welds with Every Actuation
Upgrade from a handheld probe to a parallel weld head — and gain the pressure consistency, repeatability, and throughput that production battery welding demands. The WH2 is Sunstone's proven parallel weld head, engineered for fine-spot resistance welding applications where both electrodes need to reach the workpiece from the same side.
What Is a Parallel Weld Head — and When Do You Need One?
A parallel weld head positions two electrodes side by side, both making contact with the top surface of the workpiece simultaneously. This is the standard configuration for battery tab welding — where the nickel strip sits on top of the cell terminal, and you cannot access the underside.
The WH2 goes further than a handheld dual probe attachment by delivering pneumatically actuated, controlled electrode pressure on every weld. Instead of applying force manually — which varies with operator fatigue, angle, and pressure — the WH2 uses compressed air to drive the electrode assembly down with the same force, at the same speed, every single time. The result is a level of weld consistency that a handheld attachment simply cannot match at volume.
Key Features
Pneumatic air actuation — the WH2 is driven by compressed air, not by hand. A built-in pressure regulator means any size compressor will work; you set the desired pressure and the head handles the rest. No special compressor required.
Fine electrode pressure control from 1 to 15 lbs — the full range of weld force is precisely adjustable, giving you the ability to dial in exactly the right pressure for your material and tab thickness. Too little pressure and the weld is inconsistent; too much and you risk damaging the cell or deforming the tab. The WH2 lets you find and lock in the right setting.
Low electrode inertia — the head is designed for fast follow-on pressure, meaning the electrodes maintain contact with the workpiece throughout the weld cycle without bouncing or losing pressure. This is critical for weld quality on thin materials where electrode lift-off mid-weld causes weld defects.
Adjustable head travel height from 0 to 7.25 inches — the work clearance accommodates a wide range of part geometries, fixture heights, and cell form factors. Quick-release height adjustment lets you reconfigure between jobs without tools.
Foot pedal included — hands-free weld triggering keeps your hands on the workpiece for positioning while the foot pedal initiates the weld cycle. Each compression of the pedal delivers a complete, consistent weld actuation.
Compatible with Sunstone CD, DC, and AC welders — the WH2 connects directly to Sunstone's range of resistance welding power supplies. When paired with the CDDP-A advanced welder, the WH2 integrates with the welder's timing controls to allow programmatic squeeze time, weld trigger, and post-weld hold — all from a single foot pedal actuation.
Choosing Your Variant: Pneumatic or Manual Actuation
The WH2 is available in two actuation configurations. Both use the same parallel electrode geometry, the same 0.125" electrode diameter, and include a foot pedal, trigger cable, and 1 AWG welding cables. The difference is how the electrode assembly is driven down onto the workpiece.
Pneumatic (WH2125A) — Air-Actuated The WH2125A uses compressed air to drive the electrodes down with a consistent, pre-set force on every actuation. A built-in pressure regulator means any standard shop compressor will work. Because the pressure is set mechanically rather than applied by hand, every weld gets the same electrode force — regardless of operator fatigue, angle, or technique. This is the right choice for production environments, higher-volume work, or any application where weld-to-weld consistency is critical. When paired with the CDDP-A welder, the pneumatic head also enables fully integrated timing control for squeeze, weld, and hold — all triggered from a single foot pedal.
Manual (WH2125M) — Foot Pedal Actuated The WH2125M lowers the electrode assembly through a lever and foot pedal mechanism, with the operator controlling the descent speed and pressure by feel. This gives the user direct, tactile control over the weld and requires no air supply or compressor. It's the right choice for bench-top lab work, R&D environments, lower-volume production, or situations where compressed air isn't available. Weld pressure is still adjustable from 1 to 15 lbs — but applied manually rather than pneumatically.
Rule of thumb: if you're running a consistent production process and already have a compressor, go Pneumatic. If you're in a lab, prototyping environment, or don't have an air supply on hand, Manual gives you everything you need with one less piece of infrastructure.
What the WH2 Is Used For
The WH2 is purpose-built for parallel resistance welding — any application where both electrodes access the workpiece from the same side:
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Battery pack assembly — the primary application. Tab-to-cell welding on cylindrical, prismatic, and pouch cells at light to moderate production volumes
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Battery manufacturing prototyping and R&D — consistent, adjustable pressure lets engineers dial in weld parameters with precision before scaling
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General fine spot resistance welding — any parallel welding application where a benchtop pneumatic head is more appropriate than a handheld attachment
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Fixture-based production welding — the WH2's adjustable height and pneumatic actuation make it compatible with part fixtures and semi-automated positioning setups
The WH2 + CDDP-A: A Natural Pairing
The WH2 is the recommended weld head attachment for the Sunstone CDDP-A advanced dual pulse CD welder. When connected, the CDDP-A takes direct control of the WH2's timing — governing the electrode squeeze, weld trigger, and post-weld hold as a single integrated cycle. The operator positions the part and presses one foot pedal. The system handles the rest, with the same timing and force on every weld.
This integration is what bridges the WH2 from a standalone attachment into a production welding system — consistent enough for quality-controlled manufacturing, flexible enough for R&D and prototyping.
👉 Download the WH2 Parallel Weld Head User Manual for full setup instructions, specifications, and configuration guidance.
Why Buy the WH2 From The Maker's Chest?
75-Day Return Window — more than double Sunstone's 30-day return policy. If the WH2 doesn't fit your setup or application, you have 75 days to return it.
Expert USA-Based Technical Support — weld head setup involves more than plugging in a cable. Pressure settings, electrode selection, integration with your welder — our team can walk you through all of it.
Dual Lines of Support — access to both our in-house technical team and Sunstone's own support resources. Two channels working for you on a single purchase.
Authorized Sunstone Reseller — genuine product, full manufacturer warranty, backed by our additional support layer.
Frequently Asked Questions
What's the difference between the WH2 and a handheld dual probe (DPHP) attachment? Both put two electrodes on the same side of the workpiece for parallel welding. The difference is how electrode pressure is applied. The DPHP is pressed down by hand — so pressure varies with the operator. The WH2 is pneumatically actuated, delivering a precisely set, consistent force on every weld regardless of who is operating it. For low-volume prototyping, the DPHP is more affordable and flexible. For higher-volume or quality-controlled production work, the WH2's repeatability justifies the step up.
Do I need a specific air compressor to run the WH2? No. The WH2 comes with a built-in pressure regulator, so any standard shop compressor will work. You connect the air supply, set the desired pressure at the regulator, and the head delivers that pressure consistently on every actuation.
Which electrode variant should I choose — WH2125 or WH2250? For most battery tab welding with standard nickel strip (0.1–0.2mm), the WH2125 (0.125" electrode) is the right choice. The WH2250 (0.250" electrode) is better suited for thicker tabs, higher-power welders (400 Ws and above), or applications where a larger weld nugget is needed. If you're unsure, contact our team and we'll help you match the variant to your material.
Are electrodes included? No — electrodes are sold separately. The WH2 accepts specific electrode styles depending on the variant. Browse our compatible [Battery Welding Electrodes] collection, or contact our team for a recommendation based on your application.
Can the WH2 integrate with the Sunstone CDDP-A welder? Yes — the WH2 is the recommended weld head attachment for the CDDP-A. When connected, the CDDP-A controls the WH2's squeeze timing, weld trigger, and hold time as an integrated cycle, triggered by a single foot pedal. This gives you precise, repeatable weld cycles without manual timing variation.
What welders is the WH2 compatible with? The WH2 is compatible with Sunstone CD, DC, and AC resistance welders. It is most commonly paired with the CDDP-A dual pulse advanced welder for production battery welding applications. Contact our team to confirm compatibility with your specific welder model.
What is your return policy? 75-day returns. If the WH2 doesn't work for your setup, reach out and we'll take care of you.
Brand: Sunstone | Models: WH2125, WH2250 | Note: Electrodes not included
