How to Use the AUTOOL EM385: Programming Power, Charging, Display and Forced Start

The AUTOOL EM385 can support six different workshop jobs: hold vehicle voltage during an approved programming or diagnostic procedure, charge supported lead-acid or selected lithium batteries, provide controlled adjustable DC power, maintain power for a stationary vehicle display, attempt off-vehicle battery restoration, or support one suitable 12-volt starting attempt. It does not program an ECU, identify battery chemistry, choose a safe voltage, or prove that a battery is serviceable. Safe use begins by selecting the job first and verifying the vehicle, battery, load and mains conditions before output starts.

Updated: August 27, 2026.

Choose the right EM385 mode first

Your job	Select on the EM385	Decision that must already be known	Critical limit
Hold vehicle voltage during diagnosis, coding or programming	Programmable Power Supply → Fixed Mode or Adjustable Mode	Exact vehicle or programming procedure; Fixed is 14 V, Adjustable is 9.0–16.0 V	EM385 supplies power only; it does not perform programming
Charge a supported installed lead-acid battery	Fast Charging → Lead-acid Charging → In-car Charging	Label identifies a permitted battery type and the vehicle allows in-place charging	Maximum described in-car current is 40 A; EFB is not an in-car choice
Charge a supported disconnected or removed lead-acid battery	Fast Charging → Lead-acid Charging → External Charging	Label, delivered manual and screen agree on chemistry	Maximum described external current is 20 A; EFB is external only when explicitly offered
Charge a supported lithium battery off the vehicle	Fast Charging → Lithium Battery Charging → LFP or NCM	Exact label identifies LFP or NCM and battery instructions permit this method	Maximum stated lithium charging current is 20 A/12 V
Power a known DC load	Fast Charging → Adjustable Power Supply	Required voltage, current, polarity and connection points are documented	1–20 A at 3.0–8.9 V; 1–100 A at 9.0–16.0 V
Maintain power for a stationary vehicle display	Vehicle Display Mode	Vehicle procedure supplies the target within 9.0–16.0 V	Not a programming-mode substitute or unattended supply
Attempt recovery of a severely discharged supported battery	Battery Restoration	Battery is removed, physically safe and correctly identified	Conditional result; never an in-vehicle repair
Support one vehicle-start attempt	Forced Start	Exact vehicle procedure allows external support and demand is within the EM385 boundary	Treat 400 A/12 V as a transient ceiling, not guaranteed compatibility

The nameplate on the delivered unit is the final authority for mains input. Regional input configurations exist. Do not infer universal 110/220-volt compatibility from an online specification, a manual table or another EM-series machine.

Before you connect anything

• Read the delivered manual and keep it in the work area. A current copy can also be located through the AUTOOL manual center.
• Identify one job before choosing a menu path. Programming Power, battery charging, Adjustable Power, Vehicle Display, Restoration and Forced Start are not interchangeable.
• Read the battery or equipment label. Record chemistry, nominal voltage, polarity, connection state and any manufacturer charging or support restrictions.
• Match the grounded outlet, input voltage and circuit protection to the EM385 nameplate. Never defeat protective earth.
• Work on a stable surface in a dry, clean, bright and well-ventilated area. Keep flames, sparks, conductive debris and corrosive material away.
• Wear eye protection and insulated gloves. Keep the unit away from the battery and leave both cooling fans unobstructed.
• Inspect the housing, mains lead, output cable, connector and clamps. Do not operate damaged equipment.
• Do not begin battery charging above 36°C ambient, and disconnect immediately if battery temperature exceeds 45°C.
• Follow the manual’s restriction for people with a pacemaker or other implanted cardiac device before approaching an energized machine.

Common setup and connection

Step 1: Identify the controls and stop devices

On the front, locate the 4.3-inch touchscreen, output interface, Left, Right, OK, Stop and Return buttons, plus the red emergency-stop control. At the rear, locate the mains-input interface, main power switch and two cooling fans. The screen accepts touch input; Left and Right can move through choices, OK confirms, Return moves back, and Stop ends normal output.

Step 2: Place the EM385 safely

Set the unit on a dry, stable surface and never directly on a battery. Keep at least the manual’s recommended 50 cm clearance from other objects where practical. Use the output-lead length to separate the machine from battery gases, and route both leads away from sharp edges, heat, belts, fans, tires and pinch points.

Step 3: Verify the delivered mains version

Read the input rating on the unit in front of you. Confirm that the outlet voltage, protective earth, plug and branch protection match it before inserting the mains lead. If the nameplate, plug or supply is unclear, pause the task and have the circuit checked.

Step 4: Identify the battery, vehicle or powered load

For a battery job, read the physical label rather than judging chemistry from case shape. Record whether it is Standard lead-acid, AGM flat plate, AGM spiral, GEL, EFB, LFP or NCM and whether it will remain installed, be disconnected or be removed. For programming, display or forced-start work, confirm the exact 12-volt vehicle procedure. For Adjustable Power, obtain the load’s required DC voltage, maximum current, polarity and approved connection points.

Step 5: Connect the supplied output cable with power off

Keep the rear switch off and leave mains disconnected. Seat the supplied output connector fully in the front interface. Arrange the red and black clamp leads so they cannot touch each other or bridge nearby metal. Do not substitute an undersized cable or modify the connector.

Step 6: Attach the clamps with correct polarity

Use the exact vehicle, battery or powered-load procedure to locate positive and the approved negative connection point. Attach red to positive and black to the approved negative point. Keep your face away from a battery, avoid sparks near vents and confirm that neither clamp can rotate into adjacent metal.

Step 7: Power on and clear the initial screen

Connect the verified mains lead and switch on at the rear. Confirm that the touchscreen starts normally and that the emergency stop is released. Do not enter a work mode while Battery Not Connected, Reverse Polarity, Temperature Abnormality, Emergency Stop or a mains/output protection message is active.

Use Programmable Power Supply mode

The AUTOOL EM385 holds vehicle voltage while a separate scan tool, computer and approved procedure perform diagnosis, coding or programming. The vehicle procedure controls the target voltage and every ECU action.

Step 8: Choose Fixed or Adjustable mode

Touch Programmable Power Supply. Choose Fixed Mode only when the written procedure calls for the EM385 fixed 14-volt output. Choose Adjustable Mode when the procedure requires another target within 9.0–16.0 volts. Tap the voltage field and enter the value on the keypad, or use Left and Right, then confirm with OK.

Step 9: Recheck battery charge and vehicle preparation

Read the on-screen connection prompt. Confirm correct polarity, stable terminals and a sufficiently charged vehicle battery before beginning. Complete every vehicle-side requirement for ignition state, doors, lighting, networks, cooling, accessories and charger connection before the separate diagnostic or programming process starts.

Step 10: Start support and monitor the entire session

Press OK to begin output. Watch EM385 voltage and current, the cables, battery temperature and the separate vehicle procedure continuously. The manual states a maximum programming output of 150 A for about three minutes. If internal temperature reaches 70°C, maximum output can be limited to 50 A; after cooling to 50°C, the higher ceiling can return. Plan from the vehicle’s measured demand rather than treating 150 A as unlimited continuous output.

Charge a supported battery

Step 11: Choose the real battery location first

For a lead-acid battery, select Fast Charging → Lead-acid Charging, then select its actual connection state. In-car Charging is only for a supported installed battery when the vehicle procedure permits charging in place. External Charging is for a disconnected or removed battery. The operating pages describe up to 40 A in-car and up to 20 A external; those are mode ceilings, not a reason to choose the wrong location.

EFB is never an in-car choice. Use External Charging for an EFB only when the delivered manual and exact EM385 screen explicitly offer EFB there and the physical label confirms it. Otherwise use a charger approved for that exact battery.

Step 12: Select and reconfirm the lead-acid type

Choose the chemistry printed on the battery label: Standard lead-acid, AGM flat plate, AGM spiral or GEL, plus EFB only under the external-only condition above. Press OK, then compare the confirmation screen with the label a second time. Similar case shapes do not make the types interchangeable.

Step 13: Select LFP or NCM only off the vehicle

Disconnect and remove the battery as required by its manufacturer before using Fast Charging → Lithium Battery Charging. Choose LFP only for a label that explicitly identifies lithium iron phosphate, or NCM only for an identified nickel-cobalt-manganese battery. Confirm that the battery instructions permit external charging through these terminals and that its battery-management system is intact. The manual states a 20 A/12 V maximum for this path.

Step 14: Monitor charging to a named end state

Start the selected charge cycle and remain present. Watch displayed voltage, current and progress as well as battery temperature, venting and case condition. Normal automatic completion is shown by Charging Completed. If you intentionally end earlier, press Stop and wait for output to cease before touching a clamp.

Use Adjustable Power Supply only for a documented load

Step 15: Define the adjustable-supply load before connection

Obtain the equipment manufacturer’s required DC voltage, expected current, polarity, connection points and power-up sequence. The EM385 manual allows 1–20 A at 3.0–8.9 V and 1–100 A at 9.0–16.0 V. Those ranges describe the machine, not proof that an unknown component can accept the output.

Step 16: Enter voltage and current with output stopped

With output inactive, select Fast Charging → Adjustable Power Supply. Tap the voltage and current fields and enter values that do not exceed the documented load requirement or the applicable EM385 range. Recheck the decimal point, polarity and clamps before confirming. Incorrect selection can damage the connected equipment.

Step 17: Energize, observe and respect thermal reduction

Start output and monitor voltage, current, connection temperature and load behavior continuously. The manual says that operation above 1200 W for three minutes or an internal temperature of 70°C can reduce the maximum available current to 50 A. The set value may become available again after internal temperature falls below 50°C. Do not treat protection as extra working capacity.

Use Vehicle Display Mode

Step 18: Set display voltage from the vehicle procedure

Select Vehicle Display Mode and set the target within 9.0–16.0 V only after checking the vehicle procedure. The manual says EM385 applies a small float current during standby and can provide up to 40 A when vehicle discharge is detected. It also says a setting below battery voltage is automatically changed to battery voltage plus 2 V, so the displayed operating value must be checked before relying on it.

Step 19: Monitor the stationary vehicle load

Start display support and remain with the vehicle. Keep unnecessary loads off unless they are part of the planned display, watch voltage and current, and periodically inspect clamp position, leads and battery temperature. End the session before changing a setting or connection.

Use Battery Restoration only off the vehicle

Step 20: Remove, identify and inspect the battery

Use the vehicle procedure to disconnect and remove the battery. Put it in an open, shaded and ventilated location, confirm that the delivered manual supports its chemistry, and inspect it again. Restoration is intended for some severely discharged batteries; the result depends on battery condition, and the process can cause fluid loss or internal drying.

Step 21: Run restoration and interpret the result correctly

Reconnect the isolated battery using the common steps, select Battery Restoration, confirm the removal prompt and remain present. The manual describes three automatic results: Restoration Completed after 14.6 V is reached and float charging continues for two hours; Restoration Failed if a severely discharged battery does not rise to 9 V within one hour; or No Battery Restoration Required if initial voltage is above 12.6 V.

Use Forced Start only after a suitability check

Step 22: Confirm that forced-start support is appropriate

Consult the vehicle procedure before connecting. Confirm a 12-volt system, approved external-support points and a starting-current requirement inside the EM385 boundary. Product information uses below 3.0 L as a broad qualifier, but engine size alone does not prove electrical compatibility. Use 400 A/12 V as a transient ceiling; do not rely on the higher end of any conflicting range.

Step 23: Select Forced Start and read the prompt

With the common connection checks complete, select Forced Start and confirm. Recheck red-to-positive and black-to-approved-negative polarity, then press OK. The interface prompts you to start the vehicle. Keep the leads clear of moving parts and stand where the screen, clamps and vehicle can all be observed.

Step 24: Make one controlled start attempt and end support

Crank only as allowed by the vehicle procedure. When current exceeds 50 A, the screen changes to show starting voltage and current. The manual describes protection interruption around the 400 A boundary, including a 500-millisecond overcurrent condition. Resume only after the cause and vehicle suitability have been reassessed. Once the engine starts, end support and follow the vehicle procedure for safe disconnection.

Alerts, shutdown and storage

Step 25: Treat every alert as a stop-and-check gate

For Battery Not Connected, stop and inspect clean terminal contact before one careful reconnection. For Reverse Polarity, end output and remove the clamps before correcting polarity. For Temperature Abnormality, follow the manual’s cooling instruction and keep the fans running; do not continue if the warning appears immediately on a cold unit. Release Emergency Stop clockwise only after the reason it was pressed has been resolved.

AC overvoltage, undervoltage, input overcurrent, output overvoltage, output overcurrent, leakage and short-circuit warnings require the task to stop. Correct only an obvious external supply, battery, clamp, cable or load condition. Never open the case or bypass a protection state.

Step 26: End the active function normally

Finish the separate vehicle or powered-equipment procedure first when applicable, press Stop on the EM385, and wait until the active-output screen ends. During charging, use the same Stop-first rule if the job is ending before automatic completion. Do not change mode, voltage, current, chemistry or connection while output is active.

Step 27: Disconnect, inspect and store

After output stops, remove the clamps in the order required by the vehicle, battery or equipment procedure, switch off at the rear and unplug mains. Inspect the housing, output connector, clamps and both leads. Coil the cables without sharp bends and store the EM385 dry, clean and ventilated, away from children, corrosive liquids, heat and humidity.

Seven mistakes that cause most EM385 problems

1. Treating the EM385 as the ECU programmer instead of a support supply.
2. Guessing programming, adjustable or display voltage instead of using exact equipment information.
3. Selecting battery chemistry by appearance or charging EFB in-car.
4. Charging LFP or NCM while the battery remains installed, or selecting lithium chemistry from memory.
5. Running restoration while the battery remains connected to the vehicle.
6. Selecting Forced Start from engine size alone or repeatedly resetting protection after a no-start.
7. Removing clamps or pulling mains before Stop has ended normal output.

EM385 questions answered

Can the EM385 charge a lithium battery?

Yes, but only in the dedicated lithium path for an identified LFP or NCM battery removed from the vehicle and approved for the method by its manufacturer. The manual gives a maximum of 20 A/12 V. A different lithium chemistry or unknown battery-management condition is not covered.

Can I charge an EFB battery while it remains in the car?

No. Current EM385 guidance makes EFB an external-only task. Proceed only if the battery is disconnected or removed and the delivered manual and screen explicitly offer EFB under External Charging. If they do not, use an EFB-approved charger.

Is 150 A continuously available in Programmable Power Supply mode?

No continuous 150 A promise should be assumed. The manual describes about three minutes at maximum programming output and temperature control that can reduce the ceiling to 50 A at 70°C until the unit cools to 50°C.

What is the difference between Adjustable Power and Vehicle Display Mode?

Adjustable Power is for a documented DC load and lets you choose both voltage and current within one of two ranges. Vehicle Display Mode is a vehicle-battery support path with its own automatic behavior and up-to-40 A description. Neither should replace Programmable Power Supply during an approved programming procedure.

Does the 400 A figure mean Forced Start works on every car below 3.0 L?

No. The figure is a transient ceiling, and displacement is only a broad product qualifier. Battery condition, system voltage, starter demand, terminal arrangement and exact vehicle instructions still decide whether support is appropriate.

Does Restoration Completed mean the battery is healthy?

No. It identifies the end of the EM385 cycle. It is not a capacity, conductance, load or vehicle-serviceability test. Evaluate the battery separately before reinstalling it.

What should I do if an alert returns after a connection check?

Stop using the unit. A persistent warning is not a request to open the case or keep resetting protection. Isolate the EM385 and obtain qualified support.

Final operating checklist

• Exact job, operating procedure and supported battery or load identified.
• Delivered nameplate matched to a grounded outlet and correct circuit protection.
• EM385 stable, dry, ventilated and separated from the battery.
• Cables, clamps, polarity and approved connection points checked.
• Correct mode, battery location, chemistry, voltage and current confirmed.
• LFP, NCM, EFB and Restoration kept inside their off-vehicle boundaries.
• Programming, Adjustable Power, Vehicle Display and Forced Start kept as separate workflows.
• Screen, current, voltage, temperature, leads and work area monitored throughout.
• Any warning treated as a stop-and-check condition.
• Stop used before clamps, settings or mains connection are changed.
• Battery condition, powered-load result or no-start cause verified separately before return to service.

The EM385 is easiest to use when each mode retains its own decision boundary. Let exact vehicle information control programming and display voltage, let the physical battery label and installation state control charging, give Adjustable Power only a documented load, reserve restoration for an isolated battery, and treat Forced Start as a carefully checked transient task. That method gives every job a clear start condition, completion check and safe stop point.