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How To Wire Your Lester Summit II Battery Charger 1050W

1050W Lester Summit II Battery Charger

This is a resource for those needing directions on how to wire their Lester Summit II Battery Charger. These units are very well designed and universal. They work great in all applications though some configuring is required. The 1050W version is specific for 24 volt applications and packs a punch at 25 amps. It also has an auto voltage feature that will allow charging 36 volt & 48 volt applications as well. Learn more about the Auto Voltage feature now.

As is the trend, Lester does not include multi-page owners manuals with their products. Instead, they publish their manual online. Since Pete\’s gets a lot of calls concerning this issue, we are publishing these directions here for your convenience.

Note: These wiring instructions will only apply to the 1050W version of this battery charger. If you have the 650W  36 Volt or 48 Volt version please refer to this How To Wire My 650W Lester Summit II Golf Cart Battery Charger


If you are looking to purchase a new Lester Golf Cart Battery Charger click here to learn more and save BIG!!!!

Getting Started

First,make sure you have the correct charger and DC side cord set for your application. Refer to the DC side cord set legend below. Or, check the golf cart charger receptacle on your golf cart if you intend to use this charger in an off-board application. Otherwise, it is pretty straight forward to install and use in an on-board application. All on-board applications will simply require a ring terminal DC cord set to wire to the main positive and negative terminals on the battery bank.

1. Charger Mounting Recommendations

Proper installation is important to achieve optimum performance and life from your new charger. Always allow for as much free air space around the charger as possible.  The best mounting orientations for this charger are shown below in Figure 2-1. The preferred way to mount the charger for On-board use is with the charger base bolted to a 0.1 inch (2.5 mm) minimum thick metal plate. This provides a strong base and good thermal conductive cooling. A poor thermal conductive material is plastic or wood, though charger should still perform well.


The charger dimensions and mounting hole locations are shown below in Figure 2-2. For off-board applications an optional handle is available for ease of carrying. The charger case also has routing and securing locations for the AC and DC cord sets when they need to be routed to the opposite ends as shown in Figure 2-3.


How To Wire Your New Lester Summit II Battery Charger 1050W 24V 36V 48V

2. How To Route AC and DC Side Battery Charger Cord Set

The application (On-board vs Off-board) will determine the proper way to route the cord sets for optimal fit, function, and performance.  See Figure 2-3 below.

How To Wire Your New Lester Summit II Battery Charger 1050W 24V 36V 48V

3. Off-Board (shelf) Vs On-Board (built-in) Chargers

This section describes how the charger operates when you set the charger type to Off-Board or On-Board. You can change this setting via the ChargerConnect app under “System Profile”.   Learn More About the App Then Tap To Get the App


The charger is factory-configured with the active battery profile that you/we request on the original order to Lester Electrical. It is also factory-configured for mounting on-board a battery vehicle/machine or for off-board use in a shelf or portable application per the original order from Lester Electrical. Before (A) using the charger for the first time or (B) using the charger with a battery pack of a different type or capacity, use the ChargerConnect app to select the proper active battery profile and that the system settings match your application. Lester Summit II Series Battery Chargers Battery Profile Quick Reference

Off-Board Applications

Off-board chargers are designed to be used in shelf or portable applications. If the AC input plug is connected to power, a new charge cycle automatically starts when the DC output is connected to a battery pack of the proper voltage. Disconnecting and reconnecting AC power while the DC output remains connected to a battery pack WILL NOT automatically start a new charge cycle. Disconnecting the DC output from the battery pack IS REQUIRED to automatically start a new charge cycle.

On-Board Applications

On-board chargers are designed to be mounted on electric vehicles/equipment. If the DC output is connected to a battery pack of the proper voltage, a charge cycle automatically starts when the AC input plug is connected to AC power. This will not occur if a safety period of time has not passed since the successful completion of the previous charge cycle. Disconnecting the DC output from the battery pack IS NOT REQUIRED to automatically start a new charge cycle.

4. Battery Chemistry and Types

Battery Type -These chargers contain multiple battery profiles for different battery types and capacities. This includes wet/flooded, AGM, and gel. If your new Summit Series II Golf Cart Battery Charger is from Battery Pete\’s, the charger will be set for basic flooded batteries. Then they are always factory-configured with the active battery profile that is requested on the PO to Lester Electrical.

We recommend using the ChargerConnect app to verify that the proper active battery profile is selected. This should be done (A) before using the charger for the first time or (B) using the charger with a battery pack of a different chemistry or capacity.  If the proper battery profile is not available on the charger, the ChargerConnect app can be used to download the appropriate battery profile from the Cloud. If the battery type you are charging is not available via the ChargerConnect app (for example, if you need information for a specific lithium ion brand or chemistry), Contact Lester Electrical for more information.


Special Note – If you make a change to the active battery profile, we suggest you mark the charger ratings label or add an additional label or tag for future reference.

Connect to the ChargerConnect App

Android Devices Connect Here

Apple Devices Connect Here

Battery manufacturers frequently use the same battery cases for different battery types. Wet/flooded batteries have removable cell caps. Replace electrolyzed water (resulting from  discharging and charging the battery) through these openings.

You can identify sealed (AGM and gel) batteries by non-removable cell caps. The physical appearance of the battery case is frequently the same as a wet battery, though the cell caps are generally not removable.

Refer to the battery manufacturer\’s information panel on the battery case to determine the type of battery in your application. If the sticker is not readable or is missing, we suggest you do not use the battery charger until you can verify the specifics of the battery in your application. If your new golf cart battery charger comes from Battery Pete,  please call and a representative can help answer your questions. Otherwise we suggest you contact the company you purchased the charger from or Lester Electrical directly for further assistance.

5. AC Power Input

This charger operates at 50-60 hertz, with an AC input rating of 100-240 volts, single-phase. It has an AC operating range of 85-265 volts, 45-65 hertz and comes with an IEC 60320 C16 inlet for the AC input power as shown below. This allows you to select the AC power cord set with a proper plug compatible with your local electrical codes. The AC power cord set must be a minimum of 18 AWG (1.0 mm2) for proper operation. The set also come with an AC cord clamp to retain the AC power cord in the IEC connector.

Special Note- For those requiring an extension cord, strive to make the distance as short as possible and use the thickest industrial cord you can. This is because you will experience voltage drop over the span from the outlet to the charger. Below 108 volts, the charger may reduce output power.

6. How To Disconnect AC Power from The Lester Summit II Golf Cart Battery Charger

See image below. This is the set for the AC power-cord set inlet. To disconnect or connect you simply need to loosen the screw on the side of the clamp. Then firmly grab the IEC connector with your fingers and pull.  To install or plug back in make sure you push the plug into the charger completely. You may then tighten the AC cord clamp to secure the AC power cord to the charger.


How To Wire Your New Lester Summit II Battery Charger 1050W 24V 36V 48V


Plug the AC power cord into a properly installed and grounded outlet. If this charger includes the UL Listed symbol on its ratings label, it provides a cord set for connection to outlets operating at nominal 120 volts (or 240 volts as appropriate). If the input plug does not fit the power outlet, contact Lester Electrical for the proper cord set terminating in an attachment plug of the proper configuration for the power outlet.

6. How To Connect DC Power Cord To The 1050W Lester Summit II Series Golf Cart Battery Charger


How To Wire Your New Lester Summit II Battery Charger 1050W 24V 36V 48V

The DC side cord set attaches to the external DC terminal block on the battery charger. See Figure 6.2-1 above. Remove the connection cover (if pre-installed) to expose the DC terminal block. The DC cord connector/plug/terminals your application will require will determine proper wiring of the device. Use DC Side Common Connector Legend shown below to determine the correct wiring configuration for your golf cart battery charger receptacle plug connector or onboard application.

The DC output cord set includes a connector, plug, or terminals. The polarity of the charger DC connector/plug/terminals must be the same as the battery connector/receptacle/terminals. The BLACK DC cable must be connect to the battery negative (-), and the WHITE or RED DC cable must connect to the battery positive (+).

Note: The charger will not operate if you reverse polarity.

You may next proceed to attach the DC side cord set wires as shown in images. Refer to figure 6.2-2. for further assistance. Installation will require a #2 Phillips head screw driver. DO NOT OVER TIGHTEN SCREWS OR YOU WILL RISK DAMAGE TO THE DC SIDE JUNCTION BOX. Proper torque settings for the positive and negative terminal screws are to be 18 in-lbs (2.0 Nm).  The lockout and external temperature sense terminal connections is to be 12 in-lbs (1.35 N-m).

Next place the strain relief over the DC cord set cable/wires on the side of the DC terminal block where the cord set will exit junction box. When using individual wires for on-board applications, place the foam rubber gasket that comes on the cord set under the strain relief. Center the wires, and then tighten the strain relief screws and torque them to 9 in-lbs (1 N-m). This prevents the wires from pinching on the side of the strain relief during tightening. Replace the terminal block cover, and torque the cover screws to 9 in-lbs (1 N-m).

How To Wire Your New Lester Summit II Battery Charger 1050W 24V 36V 48V

How To Wire Your New Lester Summit II Battery Charger 1050W 24V 36V 48V

7. Vehicle Lockout Control (Optional)

If desired, interface the charger lockout/interlock control signal with the vehicle/equipment to prevent use/movement of the vehicle while the charger is in use. The lockout control signal on Terminal 2 on the DC terminal block (see Figure 6.2-1), pulls high internally through a 10k ohm resistor to battery positive (+) when lockout is not active. It is pulls low to < 1 Vdc when lockout is active. The lockout control signal is typically interfaces with the vehicle motor speed controller.

If you are uncertain of how to interface the lockout control signal with your vehicle, please contact your vehicle dealer.

For on-board use, the lockout control signal is active with AC power. Conversely, for off-board use, the lockout control signal is active when you connect a valid battery to the charger.

Based on your application, you can configure the charger as on-board or off-board via the ChargerConnect app under “System Profile”.

8. How To Use The Optional External Port ( CAN BUS Connection) On Your Summit II Battery Charger


How To Wire Your New Lester Summit II Battery Charger 1050W 24V 36V 48V

9. Bluetooth Wireless Connectivity

Download the ChargerConnect App for your new Lester Summit II Battery Charger (links above).

10. Battery Care and Maintenance – Learn More Now In This How To Article From Pete

Tips from the pros….

Although cart batteries can withstand deep-cycle duty on a daily basis, observe the following precautions to obtain good performance and maximum cycle life.

1. When installing new batteries, be sure the polarity of each battery and the overall battery pack is correct. Otherwise, battery and/or charger damage can result.

2. Fully charge new batteries before their first use because it is difficult to know how long the batteries have been stored.

3. New batteries and older batteries that have been in storage are not capable of their rated output until they have been discharged and charged a number of times. Consult the manufacturer of your batteries for more information.

4. DO NOT EXCESSIVELY DISCHARGE YOUR BATTERIES. Excessive discharge can cause polarity reversal of individual cells resulting in complete failure shortly thereafter.

5. Maintain the proper electrolyte level of wet (flooded) batteries by adding  distilled or deionized water when necessary.  Never allow the electrolyte level to fall below the top of the battery plates. Electrolyte levels lower during discharge and rise during charge. Therefore, to prevent the overflow of electrolyte when charging, it is mandatory to add water to cells AFTER they have been fully charged. Do not overfill. Old batteries require more frequent additions of water than new batteries.

6. Maintain batteries in a charged active state to prevent hard crystalline sulfates. Internal self discharge can bring about the start of this condition in as little as three days in warm temperatures. Batteries not maintained and allowed to sit in storage will self discharge, sulfate and lose capacity. Repeated charging without using the batteries between charges can recover some of the lost power, range, and life, but some permanent loss should be expected.

7. Cold batteries require more time to fully charge. When the temperature falls below 65°F, the batteries place batteries on charge as soon after use as possible.

8. Keep the tops of batteries and battery hold downs clean and dry to prevent excessive self discharge and the flow of current between the battery posts and frame. Electrolytes spilled on batteries never dry or evaporate.

9. Maintain all connections to batteries so they are clean and tight. Due to heating and discharge rates, bolted connections loosen over time. Re-tighten the connections twice yearly to the torques specified by the battery manufacturers.

10. Follow all operating instructions, cautions, and warnings as specified in this manual, on the charger, in the battery manuals, and in the vehicle manuals.

11. NEVER try to charge a frozen battery.

For those that thought this How To Article was helpful feel free to drop us a line. Or if you still have questions and need answers feel free to contact us at (772)-444-2280 or (772) 247- GOLF

Interested in purchasing a new Lester Golf Cart Battery Charger?  Follow this thread to learn more!

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Click here to safely download the complete Owners Manual For The 1050W Lester Electrical Summit Series II 36 Volt – 48 Volt Golf Cart Battery Charger.

2 thoughts on “How To Wire Your Lester Summit II Battery Charger 1050W”

  1. There is no information on what type of temperature sensor is needed for the summit 1050w charger.

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