The ISDT K4 is a high-power 8S LiPo smart dual charger built for demanding RC battery setups. It combines two independently controlled charging channels, a built-in 100–240V AC power system and a high-performance 10–34V DC input in one desktop charger.
On AC power, the K4 provides up to 400W total charging power. Connect a sufficiently capable external DC source and each channel can deliver up to 600W and 20A, giving the charger a maximum DC specification of 600W ×2 across its two independent channels.
Standard LiPo, LiFe and Li-ion batteries are supported from 1S through 8S, making the K4 particularly useful for RC users looking for an 8S LiPo charger, a high-power dual-channel LiPo charger, or an AC/DC RC battery charger capable of handling both everyday charging and larger high-capacity packs.
Quick Fit Check:
• Charger type: AC/DC smart dual-channel balance charger
• AC input: 100–240V
• DC input: 10–34V
• Maximum charging power: AC 400W total / DC 600W ×2
• Charging current: 0.2–20A ×2
• Maximum discharge power: 30W ×2
• Discharge current: 0.2–3A ×2
• Maximum balance current: 1.5A/cell
• LiPo / LiFe / Li-ion: 1–8S
• LiHV / ULiHV: 1–7S
• Parallel Task charging: up to 800W / 35A
• BattAir smart battery support: Yes
• Wireless control: ISD Link App
• CH1 adjustable DC power output: 2–30V / 1–5A
ISDT K4 Specifications
| Brand |
ISDT |
| Model |
K4 |
| Product Type |
AC/DC Smart Dual-Channel Balance Charger |
| AC Input Voltage |
100–240V |
| DC Input Voltage |
10–34V |
| Output Voltage |
DC 1–34V |
| Maximum DC Input Current |
45A |
| Charging Current |
0.2–20A ×2 |
| Maximum Charging Power |
AC 400W total / DC 600W ×2 |
| Discharge Current |
0.2–3A ×2 |
| Maximum Discharge Power |
30W ×2 |
| Maximum Balance Current |
1.5A/cell |
| LiPo Support |
1–8S |
| LiFe / Li-ion Support |
1–8S |
| LiHV / ULiHV Support |
1–7S |
| Pb Support |
1–14S |
| NiMH / NiCd Support |
1–18S |
| Parallel Charging |
Up to 800W / 35A |
| Parallel Discharging |
Up to 60W / 3A |
| CH1 DC Power Output |
2–30V / 1–5A |
| Smart Battery System |
BattAir supported |
| Wireless App |
ISD Link |
| Firmware Interface |
USB-C upgrade port |
| Operating Temperature |
0–40°C |
| Storage Temperature |
-20–60°C |
| Dimensions (L × W × H) |
176 × 183 × 57mm |
| Weight |
Approx. 1230g |
| Stock Number |
ISDTK4DCAC |
High-Power Independent Dual-Channel Charging
The K4 is built around two independently controlled charging channels, allowing two supported batteries to run separate charging, discharging or storage tasks at the same time.
With a sufficiently capable external DC power source, each channel can provide up to 600W of charging power and 20A charging current. This gives the K4 a maximum DC specification of 600W ×2 across its two independent outputs.
For RC pilots, racers and drivers who routinely prepare multiple large packs, this dual-channel architecture can reduce the time spent waiting for one battery to finish before beginning the next task.
600W ×2 explained:
This specification describes two independent channels capable of up to 600W each under suitable DC operating conditions. It does not mean one battery output provides 1200W.
AC 400W or DC 600W ×2
The K4 can operate directly from a 100–240V AC mains source, making it practical as a self-contained RC charger for home, workshop or pit use without requiring a separate external DC supply.
In AC mode, the charger provides up to 400W total charging power.
For higher-output charging, connect the K4 to an appropriate 10–34V DC power source. DC operation allows the charger to deliver up to 600W on each independent channel when sufficient input power is available.
DC power requirement: A high-power DC charger can only deliver the power supplied to it. Reaching 600W per channel requires an external DC source, wiring and connectors capable of safely supporting the required voltage, current and total wattage.
8S LiPo Charger Support on Both Independent Channels
One of the K4's most important advantages is support for standard LiPo batteries from 1S through 8S. Both channels are designed to work independently with supported battery tasks, making the K4 particularly relevant for users who have moved beyond common 4S and 6S systems and need a true 8S LiPo charger.
The K4 also supports LiFe and Li-ion batteries from 1S through 8S. LiHV and ULiHV batteries use a different official cell-count range and are supported from 1S through 7S.
-
LiPo: 1–8S
-
LiFe: 1–8S
-
Li-ion: 1–8S
-
LiHV / ULiHV: 1–7S
-
Pb: 1–14S
-
NiMH / NiCd: 1–18S
Important: The K4's 8S specification applies to standard LiPo, LiFe and Li-ion batteries. The official K4 documentation lists LiHV and ULiHV support only up to 7S.
A High-Power RC Charger for Cars, Aircraft, Helicopters and Boats
The ISDT K4 is designed as a versatile RC battery charger rather than being limited to one type of vehicle. Its combination of dual independent channels, high charging power and 8S LiPo support makes it practical across a wide range of demanding RC applications.
RC airplane and helicopter pilots can prepare multiple large flight packs during the same charging session, while RC car and boat users can charge high-capacity 4S, 6S or 8S LiPo batteries without being restricted to the power levels common on compact entry-level chargers.
The K4 can also be used with smaller supported batteries, so its higher maximum output does not prevent it from functioning as an everyday LiPo balance charger. Charging current should always be selected according to the connected battery rather than simply using the charger's maximum capability.
20A ×2 Charging: Current and Wattage Work Together
Each K4 channel supports charge-current settings from 0.2A to 20A. However, the 20A rating is a current ceiling, not a guarantee that 20A will be available with every battery.
Battery voltage, available charging wattage, AC or DC operating mode, input-source capability and the battery manufacturer's charge-rate limit all affect the practical current that can be used.
This becomes especially important when charging large 6S and 8S packs. As battery voltage rises, more wattage is required to maintain the same charging current.
Do not select charge current from charger capability alone:
Even if the K4 can provide a high charging current, the connected battery must also be rated for that charge rate.
LiPo and LiHV Balance Charging
For multi-cell lithium batteries, connect the correct balance lead and select the appropriate battery chemistry before starting a charging task.
Standard LiPo batteries should use the LiPo charging program and must not be charged above 4.20V per cell.
LiHV batteries require the dedicated LiHV program when charging above normal LiPo voltage. Only use the higher LiHV full-charge voltage when the battery itself is specifically designed for LiHV operation.
LiHV system check: A vehicle or aircraft being described as “6S” or “7S” does not automatically confirm that its ESC or onboard electronics support the higher fully charged voltage of a LiHV pack. Confirm the model's maximum input voltage before using a full LiHV charge.
BattAir Intelligent Battery Interconnection
The K4 supports ISDT's BattAir intelligent battery information system. With a compatible BattAir battery setup, the charger can access supported battery information and use that data to assist with charging configuration.
This can reduce repeated manual setup when charging compatible batteries within the BattAir ecosystem.
BattAir data functions require the appropriate compatible battery and communication hardware. A conventional battery does not gain smart-data capability simply because its main power connector can be physically connected to the charger.
Parallel Task: Up to 800W / 35A for One Battery
The K4 includes a Parallel Task mode that combines the capability of both charging channels for one battery.
The official specification lists Parallel Task charging capability of up to 800W and 35A.
This is different from the normal DC 600W ×2 specification. In normal dual-channel operation, two independent channels can manage two battery tasks. In Parallel Task mode, the two charger outputs are combined to provide greater capability to a single battery through the required connection arrangement.
Parallel Task is not the same as a conventional parallel charging board:
The K4 Parallel Task combines the charger channels for one battery. It should not be confused with connecting multiple separate batteries together on a parallel board.
Dual Task for Matched Charging Operations
The K4 also includes a Dual Task function. This allows the same configured charging, discharging or storage parameters to be applied to batteries connected to both channels.
It can simplify battery preparation when two suitable packs require the same operating settings while still using the K4's separate physical channel connections.
30W ×2 Discharging and Storage Functions
Each channel supports discharge current from 0.2A to 3A, with up to 30W of discharge power per channel.
The K4 also includes a Storage task for bringing supported rechargeable batteries toward an appropriate storage condition when they will not be used immediately.
When Parallel Task is used for discharging, the official specification lists up to 60W / 3A.
A separate battery-destroy or decommissioning task is intended only for batteries that will be permanently removed from service and should not be used as a normal storage function.
Battery disposal mode is permanent: Do not use the battery-destroy function on a pack that you intend to recharge or use again.
CH1 Adjustable DC Power Supply Mode
Channel 1 can also operate as an adjustable DC power output for suitable hobby and bench applications.
The K4 documentation specifies an adjustable output range of:
-
Voltage: 2–30V
-
Current: 1–5A
This is a DC output function and should not be confused with the separate external DC input used to power the K4 charger itself.
Full-Color Dual-Channel Charging Display
The central color display provides information for both charging channels. Depending on the active task, the K4 can display values such as charging current, battery voltage, elapsed time, capacity and other battery-management information.
During supported balance-charging tasks, the charger can also display individual cell voltage and cell internal-resistance information, giving the user a clearer view of pack behavior during charging.
ISD Link App Wireless Control
The K4 supports wireless connection through the ISD Link App. After the charger is added to the app and the wireless connection is completed, supported charger information and battery tasks can be managed from a compatible mobile device.
If you are searching for the ISDT K4 app, use the current ISDT-supported ISD Link distribution channel rather than an unofficial or outdated third-party installation file.
ISDT K4 Firmware and Firmware Updates
The K4 includes a dedicated USB-C upgrade port for supported firmware servicing.
If you are looking for an ISDT K4 firmware update, only install firmware intended specifically for the K4. Firmware for another ISDT charger should not be used simply because the products share similar menu structures or charging functions.
The system also includes functions such as self-test, calibration and system information for maintaining supported charger settings.
ISDT K4 Calibration
The K4 manual documents calibration functions for supported input voltage, output voltage and balance voltage. Calibration should only be performed when appropriate and according to the official K4 procedure rather than through undocumented adjustments.
ISDT K4 Manual
For complete setup instructions, supported battery programs, charging parameters, Dual Task, Parallel Task, DC Power mode, wireless connection, calibration and operating safety, view the ISDT K4 User Manual.
Who Is the ISDT K4 8S LiPo Charger Best Suited To?
- RC users looking for a high-power 8S LiPo charger.
- Pilots and drivers who regularly charge large-capacity 6S and 8S RC batteries.
- Users who want a dual-channel LiPo charger for two independent battery tasks.
- Large RC airplane and helicopter users preparing multiple flight packs during the same session.
- RC car and boat users who want up to 20A per charging channel where the battery and available wattage permit.
- Users who want convenient AC charging at home plus substantially more power from a suitable external DC source.
- BattAir users who want supported smart battery information.
- Users who want wireless charger monitoring and task control through ISD Link.
Compare More RC and LiPo Battery Chargers
To compare the K4 with other ISDT AC/DC, DC-only, dual-channel and high-power charging systems, explore the ISDT chargers, dischargers and battery tools collection at CNHL.
If you want to compare the K4 with chargers from other brands or find a different power level, channel count or supported battery range, browse the LiPo battery chargers collection.
What to Check Before Buying
- Confirm that your battery chemistry and cell count are supported by the K4.
- For standard LiPo, LiFe and Li-ion packs, support extends to 8S.
- For LiHV and ULiHV packs, the official K4 specification extends to 7S.
- Remember that AC charging power is 400W total, while DC operation can provide up to 600W per channel.
- Confirm that the external DC power supply can actually support the intended charger load.
- Do not assume 20A is available at every battery voltage or with every battery.
- Always follow the battery manufacturer's permitted charging rate.
- For multi-cell lithium batteries, connect the correct balance lead and confirm polarity before starting.
- If using Parallel Task, follow the required connection arrangement described by ISDT.
- Confirm that the AC power cable or regional plug supplied with your selected version matches your local mains outlet.
FAQ
What type of RC charger is the ISDT K4?
The ISDT K4 is a high-power AC/DC smart dual-channel RC battery charger. It supports two independent battery tasks and is designed for a wide range of RC car, aircraft, helicopter and boat batteries.
Is the ISDT K4 a dual-channel LiPo charger?
Yes. The K4 has two independently controlled charging channels. With a suitable DC input source, each channel can provide up to 600W and 20A within the charger's operating limits.
Is the ISDT K4 a good charger for 8S LiPo batteries?
The K4 officially supports standard LiPo batteries from 1S through 8S, and its high-power DC mode makes it particularly useful for larger 8S packs. Each channel supports up to 600W and 20A on DC input, although actual charging current depends on battery voltage, available input power and the battery manufacturer's permitted charge rate.
Can the K4 charge 8S LiHV batteries?
No. The official specification lists LiHV and ULiHV support from 1S through 7S. The 1–8S specification applies to standard LiPo, LiFe and Li-ion batteries.
How much power does the ISDT K4 provide on AC?
The K4 provides up to 400W total charging power when operated from a compatible AC mains source.
How much power does the K4 provide on DC?
With an appropriately rated external DC source, the K4 can provide up to 600W on each independent channel, giving a maximum specification of 600W ×2.
What is the maximum charging current?
Each channel supports charging-current settings from 0.2A up to 20A. Actual available current is also limited by battery voltage, available wattage, input-source capability and battery charge-rate limits.
What is Parallel Task on the ISDT K4?
Parallel Task combines both charging outputs to provide greater charging capability to one battery. The official specification lists up to 800W / 35A for parallel charging. This is different from using a conventional parallel board to connect several batteries together.
What is Dual Task?
Dual Task allows the same configured charging, discharging or storage parameters to be applied to batteries connected to both K4 channels.
Can the ISDT K4 work as a DC power supply?
Yes. Channel 1 can operate as an adjustable DC power output with voltage from 2–30V and current from 1–5A.
What app does the ISDT K4 use?
The K4 uses the ISD Link App for supported wireless monitoring and charger task control.
Can the ISDT K4 firmware be updated?
Yes. The charger includes a USB-C upgrading port for supported firmware servicing. Only use firmware intended specifically for the ISDT K4.
Where can I find the ISDT K4 manual?
View the ISDT K4 User Manual for battery programs, charging parameters, Parallel Task, Dual Task, wireless setup, calibration and operating instructions.
Package Includes
- 1 × ISDT K4 Smart Dual Charger
- AC power cable / regional mains connection as supplied with the selected version
Charging Safety Notice
Always confirm battery chemistry, cell count, polarity and permitted charge rate before beginning a charging task. Do not charge primary non-rechargeable batteries or damaged, swollen or otherwise unsafe rechargeable batteries.
For multi-cell lithium batteries, use the correct balance connection and appropriate chemistry program. Standard LiPo cells must not be charged above 4.20V per cell. LiHV batteries require the correct LiHV charging mode when using a higher full-charge voltage.
Operate the K4 in a cool, well-ventilated area on a heat-resistant, non-flammable and electrically insulating surface. Do not obstruct the cooling vents, and never leave the charger or connected batteries unattended while charging or discharging.
