HiKOKI / Hitachi power tool repair
HiKOKI (Hitachi) DH/DV/DS/G/WH/C MultiVolt 18V/36V: brushless electronics, BSL18/BSL36, battery rebuild, gearbox, carbon brushes.
HiKOKI is the former Hitachi Power Tools, and that brand transition is the most interesting story in power tools of the past decade. In October 2018, Hitachi Koki Co., Ltd. (the Hitachi group's power-tool division since 1948) was sold to Koki Holdings, and the tool brand became HiKOKI. Mechanically nothing changed: the same engineers, the same factory in Ibaraki Prefecture, the same lifespan, and the same BSL18 mounting interface — meaning the battery you bought for a Hitachi DV18DGL in 2014 still works on a new HiKOKI WH18DC in 2024. That is a rare case where a brand transition does not break compatibility, and Latvian owners of older Hitachi tools did not have to throw away their battery investment.
The typical workload: carbon-brush replacement (on brushed models like DH18DBL, DV18DGL — standard 6×9×14 mm brushes, 200–400 hour service life), gearbox rebuild (bevel-gear wear on rotary hammers like DH36DPA after intensive concrete work), brushless controller replacement (on newer brushless models with DBL2, DBAL, DBBVL, DC suffixes), BSL18 and MultiVolt BSL36A18 battery rebuilds (the new standard from 2018 onward). The HiKOKI MultiVolt detail worth knowing: it is a "smart" battery that auto-reconfigures as 36V on flagship tools (DH36DPA rotary hammer, C36DYA circular saw) and as 18V on standard tools (DV18DBXL, DS18DBL2). Inside there are two Li-Ion 21700 cell groups: 5S2P for 18V and 10S1P for 36V, and the BMS switches topology based on the tool's signalling. On a BMS fault the charger or tool no longer "sees" the battery — we diagnose and repair this electronics at the component level.
We cover the full lineup: DH-series rotary hammers (DH18DBL, DH36DPA, DH26PB), DV-series impact drills (DV18DGL, DV18DBXL), DS-series drill/drivers (DS18DGL, DS18DBL2), WH-series impact wrenches (WH18DC, WH36DC), G-series angle grinders (G18DSL, G18DBAL2, G18DBBVL), C-series circular saws (C18DBAL, C36DYA), plus UC18YML2 and UC36YSL chargers and BSL18 (1830M, 1840M, 1860M, 18A) and MultiVolt BSL36A18, BSL36A18B, BSL36B18 batteries. We agree the cost before any work; on-site diagnostics is free. Battery cell replacements carry a 6-month warranty; everything else, 3 months.
Popular models we repair
- HiKOKI DH18DBL / DH36DPA / DH26PB — rotary hammers
- HiKOKI DV18DGL / DV18DBXL — impact drills
- HiKOKI DS18DGL / DS18DBL2 — cordless drill/drivers
- HiKOKI WH18DC / WH36DC — impact wrenches
- HiKOKI G18DSL / G18DBAL2 / G18DBBVL — angle grinders
- HiKOKI C18DBAL / C36DYA — circular saws
- HiKOKI BSL18 / BSL36 / MultiVolt — batteries
Common problems we fix
- DH rotary hammer has lost impact — wear in the impact mechanism or gearbox gears
- BSL18 / BSL36 / MultiVolt battery will not hold charge — Li-Ion degradation or BMS fault
- Brushless DH18DPC / DS18DBL2 will not start — controller or thermal sensor failure
- Carbon brushes worn on brushed models — sparking, power loss
- UC18YML2 / UC36YSL charger does not "see" the battery — charge-board fault
- G18DSL angle grinder vibrating — spindle support bearing play
- Trigger does not lock speed — speed controller contact oxidation
- C18DBAL circular saw will not reach full speed — winding or electronic-board breakdown
- MultiVolt does not switch between 18V and 36V — BMS switching fault
Hitachi → HiKOKI: what changed and what stayed the same
In 2018 Hitachi Koki Co., Ltd. (the power-tool arm of the Hitachi group) was sold and renamed Koki Holdings, and the tool brand became HiKOKI. For owners that meant new housing colours (green with blue accents instead of the classic Hitachi green), but the internal construction and battery platform stayed compatible. The older 18V Slide-Pack BSL18 platform remains in production, and Hitachi-era batteries work on new HiKOKI tools and vice versa.
What genuinely changed is the introduction of the MultiVolt platform: a single BSL36A18 / BSL36A18B battery automatically operates as 36V on high-power tools (DH36DPA, C36DYA) and as 18V on standard tools (DV18DBXL, DS18DBL2). It is a smart switch inside the BMS, and on a fault the tool or charger stops "seeing" the battery. We repair this electronics and replace damaged Li-Ion cells when needed. Battery work carries a 6-month warranty.
Brushless HiKOKI — what fails and how it is repaired
The brushless HiKOKI line (models with DBL2, DBAL, DBBVL or DC suffixes) is built around a controller PCB that drives power MOSFETs to generate three-phase AC for the brushless motor. Compared to brushed models that means: no brushes to replace, higher efficiency and torque — but a new dependency on the electronics being healthy.
Typical brushless HiKOKI faults: a MOSFET breakdown under overload, a Hall-sensor failure on the rotor (the tool will not start or runs in jerks), a thermal-sensor fault on the board (the tool drops into protection mode under light load), or shunt-resistor damage after a short circuit. We diagnose the board at the component level with an oscilloscope and replace individual components where possible — significantly cheaper than swapping the whole electronic module. If the PCB itself is damaged (burnt traces, broken contacts), we fit an original or compatible board outright.
Pricing & warranty
Fast on-site diagnostics. Warranty: 3 months.
If the repair cost changes during the process, the technician will call to agree on the new price. No work is done without your consent.
Frequently asked questions
Why customers choose SATER
- Armature rewinding and bearing replacement. We rebuild grinder, rotary hammer and drill motors — not just swap the whole unit.
- Replacement battery pack assembly. We build battery packs for cordless tools from top-brand cells.
- Festool, Makita, Bosch, DeWalt, Hilti. We repair professional and consumer tools — and know the quirks of each brand.
- 30+ years of experience. The service centre has been operating since 1993.
- We serve all of Latvia. Electronics service centre in Riga — we accept devices from anywhere in the country.