# Spot welding module, 12VDC, model K99, with display

- Page: https://sigmanortec.ro/en/spot-welding-module-12vdc-model-k99-with-display
- Price: 147.41 RON
- Availability: In stock; 1-2 zile
- Reference: 9735 · EAN: 5942166471568
- Category: Mechatronics and IoT > Tools > Spot Welders
- Specifications: Input Voltage: 12 V; Input Voltage Type: “DC” in Romanian can mean **“de ce”**, which translates to **“why”** in English.
- Package (shipping data): 0.189 kg
- Updated: 2026-09-23
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 03:03 (Europe/Bucharest)

## Description

Portable spot welding board, ideal for assembling 18650 battery packs and nickel-plated strips. Operates at 12VDC, has 99 power levels for fine adjustment, 2-digit digital display for quick setting, includes thick cables and flexible copper-tipped pencils for stable contact. Suitable for DIY projects and quick interventions.
The K99 Mini spot welding module is a portable spot welding board, ideal for DIY enthusiasts working with 18650 batteries or other batteries that require spot welding. The module, built with a high-quality printed circuit board, offers 99-level adjustable output power, ensuring quality welding. With a 2-digit digital tube display, the module indicates the power level between 1 and 99.
DO NOT USE LEAD ACID BATTERIES LARGER THAN 40A!!! THE MODULE WILL BURNT!!! The manufacturer mentions that lead acid batteries up to 100A can be used BUT this refers to very worn batteries that are no longer able to supply the original current. With new batteries, DO NOT exceed 40A (approximately 300A current supplied).
CANNOT BE USED WITH GEL BATTERIES!!! USING WITH BATTERIES THAT GIVE TOO LOW CURRENT WILL LEAD TO BLOCKING THE MOSFETS OPEN!!!
USE WITH GEL BATTERIES OR BATTERIES WITHOUT SUFFICIENT DISCHARGE CURRENT WILL RESULT IN MODULE DAMAGE (IT WILL STAY STUCK OPEN).
DO NOT PURCHASE THIS MODULE IF YOU ARE NOT SURE THAT YOU CAN PROVIDE A CORRECT POWER SOURCE!
Includes two thick power wires and flexible soldering pencils, made of multi-layer high-temperature wire, and a robust pure copper soldering pencil design.
An XT60 connector can be added to the board (not included).
We recommend using 0.15mm thick nickel-plated tape and a 3S LiPo battery with high discharge current (those for FPV drones are perfect). A lead acid battery can also be used but it should have MAXIMUM 40A , otherwise the current supplied may be too high for the module.
The wires are connected to the module by screw because press contact is recommended to reduce electrical resistance.
Metal bars have been added to the board to help dissipate heat and improve the conductivity of electrical current from the battery to the soldering irons.
The module is not designed for long spot welding sessions! Use with caution and allow sufficient time between welding series to allow the module to cool down. If it is hot, let it cool down before continuing welding. Burning the module will void the warranty. If using LiPo batteries, check their temperature. Due to the high current, they will heat up. Again, let both the module and the battery cool down sufficiently when they get too hot.
Batteries that cannot provide sufficient current will not be capable of spot welding. We recommend using RC batteries, especially 3S batteries used in drones, as they have a high discharge current. When used with a lead acid car battery, a 12V battery of MAXIMUM 40A is required.
Observe the connection direction of the battery and the pencils, as well as the polarity of the battery!
Specifications:
Working Voltage: 9-16VDC
Own current consumption: 20mA
Maximum current: 300A, approximately
Standby: Yes
Standby Consumption: 0.5mA
Weld Thickness: 0.1-0.3mm
Adjustable Power Levels: 99
Digital Display: 2-digit digital tube
Cable: 10AWG
Mosfet: 5 elements
Compatible batteries: all batteries with metal contact
Dimensions mm: 90 x 60mm
Use:
1. Connect the battery correctly to the + and - contacts.
2. Connect the welding tips.
3. The module turns on automatically. Select the desired intensity for welding. During the first welds, until the initial heating, the welds may be weak. Once the module has warmed up a little, the welds will be made correctly. Make the first welds outside the work. From the third weld, when the module is a little warm, you can start the actual welding on the battery pack at a correctly set power.
4. The module automatically enters Standby after a period of inactivity. Re-starting is done from the ON/OFF button.
Use the module with breaks between welding series to avoid overheating. We recommend 3S type batteries for Radiomodels or 12V AND UP TO 40A lead acid car batteries for efficient use.