HiKOKI (formerly Hitachi) is a Japanese professional power tool manufacturer renowned for durability and performance. Their Multi Volt battery system is a genuinely innovative approach to tool power — one battery platform that intelligently switches between 18V and 36V depending on the tool it’s inserted into. This is not a compromise solution. It’s a deliberate design that maximizes runtime, minimizes investment, and eliminates the need to carry separate battery systems on site.
Whether you’re a carpenter, electrician, site supervisor, or serious DIYer, understanding how Multi Volt compatibility works is essential. This guide covers every compatible tool, battery model, charger, and the crucial backward-compatibility rules that separate what works from what doesn’t.
How Multi Volt Works
The HiKOKI Multi Volt system uses a single battery platform that automatically adjusts its output voltage depending on the tool’s requirements. A Multi Volt battery inserted into an 18V tool delivers 18V. The same battery in a 36V tool delivers 36V. There’s no manual switching, no adapter needed, no loss of performance.
This is possible because HiKOKI’s 18V and 36V tools are engineered with intelligent battery management circuits that negotiate the correct voltage with the battery. The battery contains two 18V cell strings that can be wired in series (for 36V tools) or parallel (for 18V tools) depending on what’s connected. The system is seamless from the user’s perspective — insert the battery, the tool works at full rated power.
This approach offers a significant advantage on job sites where you might need both compact 18V impact drivers and powerful 36V rotary hammers. One set of batteries covers both applications, reducing the total weight and cost of your battery arsenal compared to systems where 18V and 36V batteries are separate platforms entirely.
TL;DR Compatibility Rules
- Multi Volt batteries (BSL36A18, BSL36B18) work in all HiKOKI/Hitachi 18V and 36V tools.
- Old 18V-only batteries (BCL1815, BCL1830) work in 18V tools only. They will not work in Multi Volt 36V tools.
- Multi Volt batteries are NOT compatible with other brands (Makita, DeWalt, Milwaukee, Ryobi, Bosch).
- Chargers: UC18YSL3 (single-port, standard) and UC18YTSL (three-port, faster for job sites).
- HiKOKI is Hitachi. Brand name changed in October 2018. All batteries are compatible across both names.
Multi Volt Battery Models
HiKOKI currently manufactures two Multi Volt battery models. Both are built on the same platform and both are fully compatible with the entire HiKOKI tool range — the difference is simply capacity.
| Battery Model | 18V Capacity | 36V Capacity | Cell Type | Weight | Key Features |
|---|---|---|---|---|---|
| BSL36A18 | 5.0Ah | 2.5Ah | Lithium-ion (21700) | 0.6 kg | Standard capacity. Best for mixed-use jobs with frequent battery swaps. Balances weight and runtime. |
| BSL36B18 | 8.0Ah | 4.0Ah | Lithium-ion (21700) | 0.95 kg | Extended capacity. Heavier but delivers longer runtime on demanding tasks (rotary hammers, saws). Ideal for all-day work without frequent charging. |
Both batteries feature LED fuel gauge indicators (three lights) so you can see remaining charge at a glance. Both are dust and moisture resistant — sealed against the ingress that can degrade battery contacts on cheaper systems. Both support rapid charging in HiKOKI’s UC18 series chargers. Runtime is proportional to the tool’s power consumption — the BSL36B18 will run roughly 1.6x longer than the BSL36A18 in the same tool, but it weighs more.
Backward Compatibility — Important Rules
HiKOKI’s one-way backward compatibility is crucial to understand.
Multi Volt batteries → Old 18V tools: YES, fully compatible. If you own an older Hitachi 18V drill or impact driver from before the Multi Volt launch, a BSL36A18 or BSL36B18 battery will work perfectly in it. The tool will run on 18V from the battery’s parallel-wired cell strings. You get to keep your old tools and benefit from newer, better batteries.
Old 18V batteries → Multi Volt 36V tools: NO, not compatible. This is the critical point. Legacy HiKOKI 18V batteries (BCL1815, BCL1830, and others from the pre-Multi Volt era) will not physically fit into, and will not function in, HiKOKI’s newer Multi Volt 36V tools. The electrical interface is different, and the battery voltage is too low for the 36V tool’s performance requirements. You cannot upgrade a 36V tool with an old 18V battery — you must use a Multi Volt battery (BSL36A18 or BSL36B18).
This is not a limitation specific to HiKOKI — it’s a physics constraint. 36V tools are designed for the full power output of a 36V supply. An 18V battery cannot deliver that, and attempting to use an incompatible battery could damage the tool or the battery.
Compatible Tools by Category
HiKOKI manufactures a comprehensive range of professional-grade 18V and 36V cordless tools. All Multi Volt tools are listed below by category, grouped by voltage platform. The 18V platform is suitable for compact drilling, fastening, and light demolition. The 36V platform is for heavier work — large-diameter drilling, high-torque fastening, demolition, and extended saws.
Drills & Drivers (18V)
| Tool Type | Model | Voltage | Best For |
|---|---|---|---|
| Driver Drill | DV18DJSL | 18V | General drilling and fastening. Two-speed transmission. |
| Compact Impact Driver | TL18DJSL | 18V | Fastening in confined spaces. Ultra-compact body. |
| Driver Drill | DS18DJ | 18V | Lightweight drilling. Single-speed fixed head. |
Rotary Hammers (18V & 36V)
| Tool Type | Model | Voltage | Bore Size | Best For |
|---|---|---|---|---|
| Rotary Hammer | DH18DSAL | 18V | SDS-Plus | Light demolition, masonry drilling. Handheld overhead work. |
| Rotary Hammer | DH36DSAL | 36V | SDS-Plus | Medium-duty demolition and drilling. Higher sustained power than 18V. |
| Rotary Hammer | DH36DPSL | 36V | SDS-Max | Heavy demolition work. Large-diameter boring in concrete and masonry. |
Circular Saws (18V & 36V)
| Tool Type | Model | Voltage | Blade Size | Best For |
|---|---|---|---|---|
| Circular Saw | C18DSL | 18V | 165 mm | Rip and crosscut in timber. Lightweight for overhead and repetitive cuts. |
| Circular Saw | C36DSAL | 36V | 190 mm | Professional-grade cutting in thick timber and engineered boards. Sustained power for all-day ripping. |
Reciprocating Saws (18V & 36V)
| Tool Type | Model | Voltage | Stroke Length | Best For |
|---|---|---|---|---|
| Reciprocating Saw | CR18DSL | 18V | 28 mm | General-purpose cutting — wood, metal, plastic. Lightweight one-handed use. |
| Reciprocating Saw | CR36DSAL | 36V | 32 mm | Heavy-duty demolition and cutting. Longer stroke for aggressive material removal. |
Jigsaws (18V)
| Model | Voltage | Stroke Length | Best For |
|---|---|---|---|
| CJ18DJSQR | 18V | 10 mm | Curved and scroll cutting in timber and sheet materials. Pendulum action for aggressive ripping. |
Angle Grinders (18V & 36V)
| Tool Type | Model | Voltage | Disc Size | Best For |
|---|---|---|---|---|
| Angle Grinder | G18DSAL | 18V | 100 mm | Light grinding, cutting, and polishing. One-handed overhead work. |
| Angle Grinder | G36DSAL | 36V | 125 mm | Heavy-duty cutting and grinding. Steel fabrication and structural work. |
Impact Wrenches (36V)
| Model | Voltage | Socket Size | Max Torque | Best For |
|---|---|---|---|---|
| WH36DH | 36V | 1/2″ | 200 Nm | Fastening large bolts on vehicles and structural steel. High sustained torque. |
Garden & Outdoor (18V)
| Tool Type | Model | Voltage | Best For |
|---|---|---|---|
| Hedge Trimmer | CH18DJSL | 18V | Hedge and shrub trimming. Lightweight for extended overhead work. |
| Leaf Blower | RB18DJSL | 18V | Yard clearing and dust management on site. Low noise, zero emissions. |
Charger Compatibility
HiKOKI Multi Volt batteries charge in any UC18 series charger. The two most common models are:
| Charger Model | Type | Charge Time (BSL36A18) | Charge Time (BSL36B18) | Best For |
|---|---|---|---|---|
| UC18YSL3 | Single-port | 45 minutes | 90 minutes | Home workshop, small job sites. Standard charger included with most new tools. |
| UC18YTSL | Three-port | 30 minutes (per battery) | 60 minutes (per battery) | Professional contractors. Charge three batteries simultaneously or rotate batteries on site. |
Both chargers are intelligent — they detect battery voltage and charge accordingly (18V or 36V batteries charge at the appropriate rate). The UC18YTSL is preferred on job sites where rotation is critical: while one battery is charging, a second is in a tool, and a third is standing by. This means you never stop work waiting for charge.
Hitachi to HiKOKI — Brand Transition
In October 2018, Hitachi Power Tools became HiKOKI. This was a rebranding, not a product change. All Hitachi-branded tools and batteries from before 2018 are fully compatible with all HiKOKI-branded tools from 2018 onwards. The connector, voltage, and control electronics are identical.
If you’re comparing old Hitachi stock against new HiKOKI inventory, there’s no compatibility issue — they all work together. The only difference is the label on the side. Battery performance, charger compatibility, and tool durability are unchanged. This means your existing Hitachi tool collection gains a new battery option when you purchase Multi Volt batteries from HiKOKI — further extending the life of your investment.
Where to Buy HiKOKI Batteries
You can find the full range of HiKOKI batteries, tools, and chargers on Amazon UK:
Buy HiKOKI Multi Volt Batteries on Amazon
Buy HiKOKI Multi Volt Tools on Amazon
Frequently Asked Questions
Do HiKOKI Multi Volt batteries work in old Hitachi 18V tools?
Yes. Multi Volt batteries (BSL36A18 and BSL36B18) are fully backward compatible with all Hitachi 18V tools manufactured before the Multi Volt system was launched. The battery’s parallel cell configuration delivers 18V to the tool, and the tool runs at rated performance. You can confidently upgrade your legacy Hitachi tools with modern Multi Volt batteries without any modifications or concerns.
Can I use old 18V batteries in Multi Volt 36V tools?
No. Legacy HiKOKI/Hitachi 18V batteries (such as BCL1815 and BCL1830) will not work in Multi Volt 36V tools. The connector may look similar, but the electrical interface is different, and the voltage is insufficient for the 36V tool’s motor and control systems. Attempting to use a legacy 18V battery in a 36V tool risks damage to both the battery and the tool. Only Multi Volt batteries (BSL36A18 or BSL36B18) should be used with 36V tools.
What is the difference between the BSL36A18 and BSL36B18?
Capacity. The BSL36A18 offers 5.0Ah at 18V and 2.5Ah at 36V, and weighs 0.6 kg. The BSL36B18 offers 8.0Ah at 18V and 4.0Ah at 36V, and weighs 0.95 kg. In practical terms, the BSL36B18 delivers roughly 1.6 times the runtime but is heavier. Choose the A18 for general mixed-use work and frequent battery swaps; choose the B18 for all-day demanding work (rotary hammers, heavy saws) where runtime matters more than weight.
Is HiKOKI the same as Hitachi?
Yes. HiKOKI is Hitachi’s new brand name for cordless power tools, adopted in October 2018. All tools, batteries, and chargers sold under the HiKOKI brand are electrically identical to Hitachi-branded products from before the rebrand. They share the same connectors, voltages, and control electronics. Any Hitachi battery works in any HiKOKI tool and vice versa. The change was cosmetic and strategic, not a shift in technology or compatibility.
Are HiKOKI batteries compatible with other brands?
No. HiKOKI’s Multi Volt battery platform is proprietary and uses HiKOKI’s unique connector design and voltage negotiation system. HiKOKI batteries will not fit into, and will not work in, tools from Makita, DeWalt, Milwaukee, Ryobi, Bosch, or any other manufacturer. Each brand has its own battery ecosystem, and cross-brand use is not possible. This is a fundamental design choice to ensure safety, performance, and longevity.
How does Multi Volt automatic voltage switching work?
HiKOKI Multi Volt batteries contain two 18V cell strings that are wired in parallel for 18V output or in series for 36V output. The battery’s electronic management circuit communicates with the tool when inserted. The tool tells the battery whether 18V or 36V is needed, and the battery reconfigures internally to deliver the correct voltage. This happens automatically — there’s no manual switch, no adapter, no user input required. Both the battery and the tool must be Multi Volt-compatible for this negotiation to work. The system is safe and reliable; it’s been in use since 2018 with no reported electrical issues when used as designed.