Heating Systems for Diving

Heating Systems with External Batteries

Santi Heating System

How the System Works

Santi is one of the best-known names in heating systems for diving. Their products include heated undersuits, vests, gloves, and external power supplies. Heating elements are built into the fabric and spread warmth across the torso and limbs. Power comes from a 12-volt external battery connected through the Santi Thermovalve or a bulkhead connector. Safety functions such as temperature limitation and current protection are included to reduce risk during use.

Available Options

Santi offers several garment types. The BZ400 undersuit combines Thinsulate insulation with heating elements and suits long dives in very cold water. The FLEX 2.0 undersuit provides lighter insulation and more flexibility while still covering the torso, arms, and thighs. Heated vests are available for divers who prefer less bulk but still need core warmth. Heated gloves integrate into the same circuit, maintaining hand dexterity in low temperatures.

Power and Runtime

• 6Ah Battery:
  Runs a heated vest alone for approximately 1.2 to 1.5 hours on high heat. If gloves or additional heated garments are powered simultaneously, the runtime decreases proportionally. Best suited for shorter dives or as a lightweight battery option.

• 10Ah Battery:
  Extends the vest heating time to roughly 2 to 2.5 hours on high setting. Moderate option balancing weight and extended runtime, suitable for medium-length technical or cold-water dives. Adding gloves or undersuits reduces total available runtime.

• 20Ah Battery:
  Provides significantly longer warmth, capable of powering a vest and gloves together for approximately 4 to 5 hours at moderate heat levels. This battery is favoured for longer deco or cold dives requiring sustained heat, but adds bulk and weight to the dive gear.

• 24Ah Battery:
  The highest capacity SANTI battery allows maximum runtime, typically exceeding 5 hours at moderate heat settings and is suitable for the most demanding technical and expedition diving profiles. This option maximises bottom time warmth at the cost of heavier battery weight and size.

Exact durations depend on garment choice, insulation layers, and ambient temperature. All batteries are contained externally, reducing the risks associated with internal power sources.

Battery Sizes and Air Travel

Battery transport is a key issue for travelling divers. Airline rules limit lithium-ion capacity by watt-hours (Wh). Packs under 100 Wh are generally allowed. Batteries between 100 and 160 Wh usually need airline approval and may be restricted in number. Anything above 160 Wh is not accepted on passenger aircraft. Many larger Santi batteries exceed this threshold, so divers often use smaller packs for travel or arrange rental batteries at their destination.

Strengths

Santi’s system is comprehensive, covering full-body heating and extremity protection. The external power supply reduces risk inside the suit. Products are widely distributed, supported by dealers, and include useful safety features.

Reported Challenges

Some divers find the heated undersuit rigid compared with non-heated alternatives. There have also been reports of issues with cables or batteries, such as connection wear or intermittent power loss. Experiences vary, but regular equipment checks and maintenance are essential.

Practical Considerations

As with all heating systems for diving, divers should not rely on electrical heating alone. Passive insulation must be adequate in case the system fails. Planning runtimes carefully, matching battery size to expected dive time, and maintaining all connectors will help avoid problems.

Visit the Santi website here

Smart-Tex

How the System Works

Smart-Tex is a Polish manufacturer that produces heated undersuits, vests, gloves, and socks. Their products are widely used as part of heating systems for diving. Heating elements are integrated into double-layer fabrics such as Polartec Power Stretch Pro. These elements distribute warmth across the torso, arms, legs, and extremities. Power comes from external lithium-ion batteries rated at 11–12 volts, with some models supporting 14.8 volts for higher output. Battery units often include adjustable power levels, controlled through a piezo switch or external controller.

Available Options

Smart-Tex offers a variety of heated garments. Full-body undersuits cover the torso, arms, and legs and allow connections for gloves and socks. Heated vests provide targeted warmth to the core and consume around 45 watts at 12 volts. Heated gloves and socks are also available, designed to connect through the undersuit’s integrated wiring. Battery packs are housed in aluminium canisters and are available in several capacities, with adjustable power levels for flexible runtime management.

Power and Runtime

Performance varies depending on the garment and power setting. With a 6.8 Ah battery:

• A heated vest alone lasts around two hours.

• Gloves or socks alone last up to three hours.

• Vest with gloves combined lasts about one hour and fifteen minutes.

Running garments on higher settings reduces runtime significantly. As with other heating systems for diving, divers must balance warmth against available battery life.

Battery Sizes and Air Travel

Airline rules restrict lithium-ion battery transport based on watt-hours (Wh). Batteries under 100 Wh are generally permitted in carry-on baggage. Packs between 100 and 160 Wh often require airline approval and are limited in number. Batteries above 160 Wh are not allowed on passenger aircraft. The Smart-Tex 6.8 Ah pack at 11.1 volts equals around 75 Wh, which falls safely within airline limits. Larger packs, however, may require prior approval or be unsuitable for travel.

Strengths

Smart-Tex garments offer good coverage, reaching both the core and extremities. The ability to run at either 12 or 14.8 volts provides flexibility. Integrated fabrics offer both passive and active insulation. Adjustable power levels allow divers to tailor heat output to dive conditions. Compatibility with common connectors such as Santi and T-Dean improves integration with existing setups.

Reported Challenges

Although lighter than some heated undersuits, Smart-Tex garments can still feel restrictive compared to unheated alternatives. Runtime drops quickly when multiple heated zones are used together. Cable routing and connectors add complexity and must be checked regularly. As with many systems, users report variable reliability of batteries and connectors.

Practical Considerations

Divers should select battery capacity to match dive length and conditions, while also considering air travel limits. Passive insulation must remain sufficient to protect the diver if the electrical system fails. As with all heating systems for diving, proper planning, equipment checks, and redundancy are essential.

Visit the Smart-Tex website here

Yellow Diving Heating System

How the System Works

Yellow Diving is a European manufacturer that produces lighting, battery canisters, and heated clothing. Their heating range includes heated shirts, gloves, and compatible power supplies. Heating elements are integrated into lightweight, stretchable garments such as the HeatShirt. Power is delivered from external battery canisters, which also serve as controllers. Divers can usually select between two power levels, with audible signals confirming the chosen setting.

Available Options

The HeatShirt Perch HU is a popular product in the Yellow Diving range. It provides warmth across the torso using vertical heating wires within a thin, breathable fabric. Heated gloves and other accessories are also available, designed to connect through standard bulkhead fittings or thermovalves. Battery canisters come in different capacities, from compact units for short dives to larger canisters designed for long runtimes or multiple devices.

Power and Runtime

The HeatShirt consumes around 45 watts at full power. A 10 Ah battery canister provides about two hours of continuous heating. Runtime varies with power level and battery size. Yellow Diving offers canisters up to 42 Ah, which extend usage considerably but add weight and bulk. As with other heating systems for diving, divers must choose between portability and extended runtime.

Battery Sizes and Air Travel

Airline rules restrict the carriage of large lithium-ion batteries. Batteries under 100 Wh are generally allowed in hand luggage, while those between 100 and 160 Wh require approval. Batteries above 160 Wh are not permitted on passenger flights. Many of Yellow Diving’s larger canisters exceed this threshold, making them unsuitable for air travel. Travelling divers often rely on smaller packs or arrange access to batteries at their destination.

Strengths

Yellow Diving offers garments that are lighter and more flexible than some other heated undersuits. The HeatShirt is easy to layer beneath existing thermal protection and does not restrict mobility. The two-level control system is straightforward to use, and compatibility with standard connectors makes integration with other equipment simple.

Reported Challenges

Battery runtime is limited when using smaller canisters, and extended dive times require larger units that are difficult to transport. Cable routing and connector maintenance are important, as poor polarity or wear can lead to performance issues. While the shirt itself is low bulk, the combination of canisters and cables adds to equipment complexity.

Practical Considerations

Yellow Diving products work best for divers who want a lightweight heating option without the bulk of a full heated undersuit. Choosing the right battery capacity is essential, as is testing connectors and power settings before each dive. For travel, divers must check watt-hour ratings carefully to avoid airline restrictions. As with all heating systems for diving, passive insulation remains essential in case of electrical failure.

Visit the Yellow Diving website here

Heizteufel Heating System

How the System Works

Heizteufel is a German manufacturer known for high-capacity heating products designed for cold-water diving. Their range includes heated gloves, base layers, vests, and external battery tanks. Heating elements are integrated into the garments, with gloves featuring “dual heat” on both the palm and back of the hand. Power comes from external lithium-ion battery tanks, available in several voltages and capacities. Divers control heat output through multi-level switches built into the battery system.

Available Options

Heizteufel offers several garments and accessories. The Dual Heat gloves provide warmth across the entire hand and fit beneath dry gloves. Heated base layers and vests deliver core warmth and integrate with the same power system. Battery tanks range from medium-capacity 14.8 V, 20 Ah units to very large 11.1 V, 50 Ah canisters. Accessories include controllers, magnetic connectors, and adapter cables, which allow integration with other brands.

Power and Runtime

Performance depends on the battery tank selected. A 20 Ah unit at 14.8 volts delivers 296 Wh, while a 50 Ah pack at 11.1 volts provides 554 Wh. These high capacities can power multiple heated zones for extended dives, though runtime decreases quickly when operating gloves and base layers together at full output.

Battery Sizes and Air Travel

Large-capacity batteries are a strength of Heizteufel, but also a limitation. Airline rules prohibit lithium batteries over 160 Wh on passenger flights. This means most Heizteufel canisters cannot be transported by air. Divers planning international travel must either use smaller, compliant packs or arrange to access batteries locally. Checking the watt-hour rating before flying is essential.

Strengths

Heizteufel provides very high power capacity, making it suitable for long dives or extremely cold water. The dual-heated gloves are effective at maintaining hand warmth and dexterity. Their wide choice of control options and adapters offers flexibility, and the waterproof housings are designed to withstand demanding conditions.

Reported Challenges

The main drawback is battery weight and bulk. Large tanks are heavy, difficult to travel with, and may affect buoyancy trim. Cable routing can become complex when several heated zones are in use, creating potential failure points. Costs are high compared with simpler systems, and air travel restrictions further limit convenience.

Practical Considerations

Divers using Heizteufel should match battery size to the dive plan and consider the additional weight during equipment configuration. Passive insulation must always be adequate in case the heating fails. For travelling divers, smaller batteries or local rental solutions may be necessary. As with all heating systems for diving, regular inspection of cables, connectors, and seals is vital for reliability.

Visit the Heizteufel website here

ScubaForce X-Heat Heating System

How the System Works

ScubaForce designed the X-Heat system to meet the demanding needs of technical divers. It now also attracts sport drysuit divers. The garment uses “Textile Heating System®” pads made from woven silver threads. These threads conduct electricity and resist breakage more effectively than traditional wire elements. The pads sit inside welded Cordura sheaths and maintain waterproof protection (IP68) even if the suit floods. Heating operates with batteries between 9 and 12 volts. The system delivers up to 60 watts of total power (≈ 30 W per pad at 12 V), achieving a maximum surface pad temperature of 44 °C (111 °F).

Available Options

The X-Heat range includes full suits with heated vest and trousers, suit variants with either Vega Valve or Apeks feedthroughs for cable routing, and accessories such as E/O cords, connectors, and blind plugs. The suit material (TecnoStretch® fleece) remains elastic, breathable, washable, and comfortable. Pads are removable so the suit can be laundered without damaging heating components. Sizes run from XXS to 2XL in unisex cuts.

Power and Runtime

Because X-Heat runs at 9–12 V, power draw depends on battery capacity and pad usage. For example, one retailer cites a setup using an 11.1 V battery of 23.8 Ah (≈ 265 Wh) yielding about 4 hours of heating with the pads. When you use both pads or operate at higher wattage, runtime falls accordingly. Battery quality, water temperature, and insulation also affect performance.

Battery Sizes and Air Travel

Airline rules for lithium battery transport apply to all heating systems for diving, including ScubaForce X-Heat. Since X-Heat requires 9–12 V external batteries, watt-hour (Wh) ratings vary. Smaller batteries will typically fall under 100 Wh and be permitted; larger packs may exceed the 100-160 Wh range and require airline approval; anything above 160 Wh often faces prohibition. If your battery pack for X-Heat exceeds those thresholds, you will need to check carrier policies or use smaller, compliant packs when flying.

Strengths

• X-Heat’s woven silver-thread heating pads offer flexibility and break resistance; they resist damage better than rigid heating wires.

• The system remains waterproof even if the suit floods, thanks to welded pad assemblies and IP68-rated connectors.

• The suit’s materials are highly breathable and stretchy, aiding diver comfort and range of motion.

• Removable pads permit washing without harming heating electronics.

 

Reported Challenges

• Full power (both pads, high output) can stress battery capacity; users must balance heat needs vs battery life.

• The need for larger battery packs increases weight, bulk, and possibly cost.

• Cable routing and connectors (E/O cords, feedthroughs) demand careful handling to avoid damage, especially under repeated flex.

• As with all electrical heating suits, diver must ensure passive insulation remains adequate should the system fail.

 

Practical Considerations

• Match battery size to dive length, water temperature, and how many pads you will use; do not plan using maximum heat for full duration unless battery capacity supports it.

• Inspect connectors and seals regularly; ensure the Vega Valve or Apeks feedthroughs are properly fitted and waterproof.

• When flying, verify your battery’s Wh rating; use airline-approved packs or arrange to source batteries at your destination.

• Include passive thermal layers; treat X-Heat as part of a combined thermal protection strategy, not the only one.

 

Visit the Scubaforce website here

AKUANA Opah Heating System

How the System Works

AKUANA’s Opah line delivers heated support via both internal and external battery configurations. The “wetsuit” version uses an integrated battery inside the vest. The “drysuit version” / “DS” version uses an external battery canister set outside the suit, with a power feed-through to the heating vest. The vest uses dual heating zones (upper back, waist / front & back zones depending on model), with carbon-fibre heating elements. A wireless wrist controller often governs the heat setting. Temperature safety cut-off (≈ 42 °C) protects against overheating.

Available Options

AKUANA offers several variants:

• Opah Heated Wetsuit Vest: Designed to be worn under a wetsuit; uses built-in battery packs (≈12 V, 2500 mAh) with three heat settings (18 W / 24 W / 30 W) and rated to ~100 m depth.

• Opah Heated Vest — External / Drysuit Version: Provides same/very similar heating zones but uses an external battery canister for safety under drysuits. Comes with feed-through valves or passage valves, and extension cables etc.

• Opah X Heating Vest: Higher power outputs (30 W / 60 W options) with external battery packs; dual-49 Wh battery units are mentioned. Depth rating ~50 m, depending on version.

Power and Runtime

• The external battery packs or canisters offer roughly 2–3 hours heating under moderate settings (30 W) for many Opah models.

• When using higher power (e.g. 60 W), runtime drops (≈ 1-1.5 hours) depending on battery capacity and temperature environment.

• For drysuit external battery version, battery canister is watertight off-suit and connects via feedthrough; this increases safety and allows battery to be replaced or removed more easily.

 

Battery Sizes and Air Travel

• The standard built-in battery for the wetsuit vest is 12 V, 2500 mAh (~30 Wh), which is well under most airline limits.

• The external battery canisters for the “DS” / drysuit version use larger packs, though specific Wh values are not always clearly published for all models. Some versions use dual 49 Wh batteries.

• Because of that, the external battery models may approach or exceed airline permitted thresholds (usually around 100 Wh for carry-on without special permission). Divers using the external versions should verify battery capacity (Wh), check airline policies, and might need to use smaller packs or arrange local rentals.

 

Strengths

• External battery version improves safety under drysuit use: battery is outside, easier to remove, cooler surface control.

• Dual heating zones give better core warmth distribution.

• Multiple power levels allow divers to adjust heat and balance runtime vs warmth.

• Depth ratings of 50–100 m are respectable for recreational / technical use.

• Temperature protection (auto shutoff) reduces risk of overheating.

 

Reported Challenges/Considerations

• Even external battery packs have weight, bulk, and cable routing issues. They may affect trim or harness setup.

• External canister and feedthroughs must be carefully installed and maintained (seal integrity, corrosion, connector reliability).

• Heat output is decent, but extremities (arms/legs) are not addressed; vest heating primarily helps core.

• For frequent travelling divers, battery compliance may complicate logistics.

 

Practical Advice

• Choose external battery version if diving with a drysuit, or when you want more safety margin for battery failures.

• Always check the watt-hour rating of the battery canister; carry documentation if flying.

• Use passive insulation under / over the vest as backup in case heating or battery fails.

• Inspect connectors, batteries, and seals regularly; rinse everything in fresh water, especially plugs.

• Test heat settings before dive; begin with moderate heat rather than cold, so system works more efficiently.

 

Visit the Akuana website here

Heating Systems with Internal Batteries

The Importance of Using Diving-Specific Internal Battery Systems

When selecting heating systems for diving, it is critical to choose products designed specifically for underwater use. Brands such as Venture Heat produce vests with sealed, waterproof batteries and connectors that meet the demands of diving environments.

Some divers have experimented with heated clothing designed for activities such as motorcycling or outdoor sports. These garments may seem attractive because they are cheaper or widely available, but they pose serious risks underwater. Consumer-grade heated vests are not built to withstand immersion, pressure, or prolonged contact with water. If used in a drysuit, water ingress can cause electrical short circuits, fire, or uncontrolled heating. This creates a real danger of internal burns or catastrophic equipment failure during a dive.

For this reason, divers should avoid adapting land-based heating garments for underwater use. Only diving-specific systems, tested and certified for submersion and depth, offer the safety and reliability required. The potential consequences of using unsuitable gear far outweigh any short-term savings.

Venture Heat

How the System Works

Venture Heat makes several heated vests and garments that use internal battery packs rather than external battery canisters. These internal batteries fit into dedicated pockets on the vest. The vest contains heating zones (commonly one on the back and one on the chest or torso). Carbon fibre heating panels or similar conductive elements deliver the heat.

The system includes multiple heat settings (High / Medium / Low) and sometimes a remote or wrist control. Because the battery is internal, the design tries to streamline connections, reduce bulk, and make the system more integrated for diver convenience.

Available Options

Some of the Venture Heat models with internal or more integrated battery setups include:

• Pro V3 Waterproof Heated Diving Vest (D616): Uses built-in/rechargeable 12V waterproof batteries (“1116B-DIVEBATTERY”) linked in pockets in the vest. It has a soft-shell neoprene exterior, heating zones on chest and back, and is rated to 100 m depth.

• SPORT V3 Waterproof Heated Diving Vest: Also uses an internal waterproof battery; simpler on/off control, coverage on upper/lower back.

• Venture Heat Pro Heated Dive Vest D616A: Distributed in Europe; uses two rechargeable Lithium-Ion batteries (10.8 V / 5000 mAh each) internally. Heating is delivered via front and back elements, three levels of heat, with waterproofing to 100 m.

Power and Runtime

• The Pro V3 vest can deliver up to 360 minutes (≈ 6 hours) of heating under some conditions, when the battery is fully charged and used at lower heating settings. At higher heat levels, or when using warmth continuously, runtime falls.

• The Sport V3 version offers about 115 minutes at full high power.

• The D616A model (with two internal 10.8 V / 5000 mAh batteries) claims a runtime between 90 min and 360 min, depending on heat level and usage.

 

Battery Sizes and Air Travel

• Internal batteries in these vests are usually rated around 10.8 V, 5000 mAh, which gives ~54 Wh per battery (10.8 × 5 Ah = 54 Wh). For models with two of these, combined energy is ~108 Wh.

• Airline rules generally allow batteries under 100 Wh in carry-on without special approval. Batteries between 100-160 Wh often require airline permission and may be limited in quantity. Anything above 160 Wh is typically prohibited. Because some internal battery configurations from Venture Heat approach or exceed 100 Wh when dual batteries are used, travellers must check whether their specific model is compliant.

 

Strengths

• Vest designs integrate battery and heating elements, reducing external bulk and simplifying rigging.

• Having internal batteries means fewer external battery harnesses or canister attachments; likely fewer points for snagging or entanglement.

• Waterproofed designs make them suitable for drysuits and wetsuits, and rated for significant depth (100 m).

• Multiple heat settings, remote controls or wrist controllers, haptic feedback help divers adjust heating in situ without removing gloves.

 

Reported Challenges

• Internal batteries still add weight; vest weight may affect buoyancy, trim, and comfort, especially in technical rigs.

• Runtime drops steeply at higher heat; internal battery capacity is limited, so continuous high output is less sustainable.

• Air travel limitations become relevant for dual-battery models: checking watt-hour rating is essential.

• Some users report fit issues (battery pocket placement causing discomfort) or remote pairing/connectivity issues over time.

 

Practical Considerations

• Treat internal battery vests as part of combined thermal protection; ensure passive layers are adequate if battery fails.

• Before each dive, fully charge batteries, test heat settings, check that remote or controllers respond.

• Inspect battery pocket seals; ensure battery connections remain dry and secure.

• For travel, carry documentation of battery Wh capacity; if possible use single battery configurations when flying.

• Balance between heat needs, desired runtime, and weight/bulk — divers in cold water or doing long decompression should plan accordingly.

 

 

Battery Technology and Suitability for Diving

Venture Heat vests use lithium-ion rechargeable batteries, designed in sealed housings for underwater use. Lithium technology provides high energy density, which means the batteries deliver more power while remaining compact and lightweight. This is essential in heating systems for diving, where divers need reliable warmth without adding unnecessary bulk to their equipment.

The waterproof battery casings are tested for depth ratings up to 100 metres. Unlike non-diving heated garments, the batteries are built to resist pressure and prevent water ingress. Safety features such as over-temperature cut-off help reduce the risk of overheating. Because the batteries are purpose-built, they are less likely to suffer the failures associated with adapting consumer products designed for land use, such as motorbike vests.

Lithium batteries do require careful management, particularly during charging, transport, and storage. However, when used within a certified diving system such as Venture Heat, they offer a safe and effective power source. This combination of compact size, energy efficiency, and underwater durability makes them suitable for use in diving conditions where performance and safety are critical.

Visit the Venture Heat USA website here

Visit the Venture Heat Europe website here

Mares XR Active Heating Vest

How it Works

The Active Heating Vest uses an internal lithium-ion battery to power built-in heating elements. It’s designed to wear under a drysuit. The heating zones focus on the chest, back, kidney area, and sides of the torso. The vest has a double zipper for easier donning, and a built-in control for selecting heat levels. Because the battery is built into the vest rather than in a large external canister, cable routing is simpler and the vest is more compact.

Available Options & Features

• The vest uses 7.4 V rechargeable lithium batteries, typically with capacity around 2,200–2,600 mAh per battery. Single battery gives 2-5 hours depending on heat setting. Option to use two batteries for extended run time. ba.com+2

• Four heat settings allow diver to adjust warmth vs battery consumption.

• Vest is lightweight and relatively thin; made of neoprene or lightweight material so as not to add excessive bulk. cuba.com+2

Power and Runtime

• Single battery (≈ 2,200 mAh / 7.4 V) gives roughly 2–5 hours of heating, depending on heat level and diver’s insulation.

• Using two batteries extends runtime. However, higher heat settings reduce the duration substantially. Heat output, ambient water temperature, diver movement, and suit insulation affect actual performance.

 

Battery Sizes & Air Travel Considerations

• The batteries are relatively small and built into the vest, which may simplify transport compared to large external canisters. A single battery of 2,200-2,600 mAh at 7.4 V produces about 16–19 Wh (Wh = Ah × V), which is well under typical airline limits for lithium batteries.

• Using two batteries doubles the Wh, still likely under many regulatory thresholds but users should verify.

• Manufacturers provide EU chargers; battery weight is around 125g.

 

 

Design and Function

The Mares XR Active Heating Vest takes a compact approach to heating systems for diving. Its internal battery eliminates the need for bulky external packs, creating a cleaner configuration under a drysuit. Adjustable heat settings allow divers to manage comfort levels and conserve power depending on dive conditions. The vest is designed to minimise bulk, offering an acceptable compromise between flexibility and thermal performance.

Limitations and Challenges

An internal battery brings certain drawbacks. Heat is delivered close to the body, which may create hot spots if the vest fit or insulation is inadequate. Battery capacity is limited, especially at high output, and endurance is shorter than that of external battery systems. Internal placement also makes it harder to identify or resolve problems such as water ingress or battery malfunction during a dive. As with all lithium systems, longevity depends on charging cycles, storage, and environmental factors.

Practical Use

Divers using this system should check the vest before every dive, ensuring seams, zips, and connections remain intact. Moderate heat settings help extend battery life and prevent overheating. Reliable passive insulation remains essential in case of failure. For air travel, divers must confirm the watt-hour rating of the batteries and comply with airline restrictions on lithium packs. Regular inspection of the battery compartment and wiring reduces the risk of technical issues.

Availability and Status

While some stock still appears from retailers, signs suggest the vest may be discontinued. Limited demand, advances in heating technology, or strategic changes within Mares’ product line could explain why it is no longer widely promoted.

 

Visit the Mares website here

Seperate Battery Packs

External battery packs give divers the flexibility to choose higher-capacity power sources for their heating systems for diving. By carrying a dedicated battery built by a different manufacturer, divers can extend runtime and maintain consistent warmth across undersuits, vests, or gloves, especially during long or deep dives. These packs allow divers to match the battery size to the specific heating garment and dive profile, providing greater control over performance compared with internal batteries.

Ammonite System

Ammonite System is a recognised leader in the manufacture of external battery packs for technical divers. Their Accu Thermo line is specifically designed to power heating systems for diving, with robust housings that combine aluminium and polymer for durability under pressure. These canisters use lithium-ion cells sealed against water ingress and connect via wet E/O cords, making them compatible with a wide range of garments.

The key strength of Ammonite lies in modularity. A single battery can power both heating garments and a primary dive light through splitters, reducing the need for multiple packs. Models such as the Accu Thermo Type 14 deliver up to 200 W and provide multiple output ports, while larger packs extend runtime for deep or lengthy dives.

There are trade-offs, however. Larger capacity packs are heavy and expensive, and divers must carefully manage trim when carrying them. Airline transport regulations also limit lithium-ion capacity, so travelling with high-Wh canisters can be problematic. Despite this, for cold-water divers seeking robust, reliable power, Ammonite remains a trusted choice.

Visit Ammonite’s website here

Gralmarine

Gralmarine has built a strong reputation in the technical and cave diving community for its rugged and powerful external battery systems. Their packs, such as the 23.8 Ah / 14.4 V model with an output of approximately 343 Wh, provide long runtimes and the capacity to drive full heating configurations, including vests, undersuits, and gloves.

Customisation is one of Gralmarine’s main advantages. Divers can choose cord length, connector type, and output configuration, tailoring the system to individual requirements. The packs are engineered with multiple outputs, enabling divers to run heated garments alongside lights or other devices without compromise.

The drawbacks are weight and transport restrictions. These packs are heavy compared to smaller systems, and their high watt-hour rating often exceeds airline limits. Nevertheless, for expedition divers who do not rely on air travel, Gralmarine offers one of the most powerful and flexible battery options available for heating systems for diving.

Visit the Gralmarine website here

Yellow Diving provides an integrated approach by producing both heated garments and the external battery packs to power them. This ensures full compatibility, as their canisters are designed to match the voltage and current requirements of garments such as the HeatShirt Perch HU, which draws around 45 W. Their packs allow divers to run garments at reduced or full power, with options for various capacities depending on dive length.

The advantage of sourcing both garments and power packs from the same manufacturer is reduced risk of compatibility problems. Yellow Diving also provides clear technical specifications, making it easier for divers to understand expected runtimes and charging requirements.

As with other external packs, there are limitations. Battery size directly impacts travel, as large lithium-ion canisters cannot always be carried on commercial flights. Weight distribution is also a consideration for in-water comfort. Despite this, for divers who primarily operate locally in cold water, Yellow Diving provides a reliable, integrated solution to heating systems for diving.

Visit the Yellow Diving website here