New Protected Version
6-Channel LiPo/LiFePO4 Low Voltage Protection Circuit + Parallel Adapter.
Provides two functions, individual low voltage protection for each channel, and provides a convenient way to connect the balance plugs for up to four Turnigy/Zippy LiPo packs in parallel. The PCB contains pads for four 7-pin JST-XH connectors. This is a very easy way to build up to 20Ah packs, and provide cell-level low voltage protection at the same time, for either LiPo or LiFePO4-based packs. The standard balancer output is via a 7-pin 3.5mm mini-terminal block.

This version now includes 5.1V zener diodes on each circuit, to help provide protection from loose connections and wiring errors causing the TC54 voltage detection chips to fail.

The LVC function provides an opto-coupled 2-wire output signal that can be connected into the ebike controller's ebrake input, or can be used to pull down the throttle signal, that goes active anytime a block of paralleled cells goes below 3.0V, for LiPo, or 2.1V for LiFePO4. This will cause the controller to temporarily cut the throttle input, which removes the load. Simple, but very effective and estremely reliable.

Options are provided for either 1, 2 or 4 boards, with the latter two having the LVC opto outputs already connected. A two-wire pigtail and a 2-pin header connector is provided for each board, or group of boards, which can be used to "daisy-chain" the opto outputs from multiple LVC/HVC/Parallel Adapter boards.

Basic option is for the PCB-only, plus a full set of illustrated assembly and test instructions, for either one, two or four LVC boards per PCB. Options are also provided for full kits. The links below are for Bill of Materials (BOM) Word files that have links to all the parts:

6s LVC BOM

A complete set of illustrated assembly, test and connection intructions is provided here:

6s-8s LVC Assembly, Test and Connection Instructions

A partial kit option is provided, which includes all non-Mouser parts, in addition to the PCB(s).

New Protected Version
8-Channel LiPo/LiFePO4 Low Voltage Protection Circuit + Parallel Adapter.
Provides two functions, individual low voltage protection for each channel, and provides a convenient way to connect the balance plugs for up to four Turnigy/Zippy LiPo packs in parallel. The PCB contains pads for four 9-pin JST-XH connectors. This is a very easy way to build up to 20Ah packs, and provide cell-level low voltage protection at the same time, for either LiPo or LiFePO4-based packs. The standard balancer output is via a 9-pin 3.5mm mini-terminal block.

This version now includes 5.1V zener diodes on each circuit, to help provide protection from loose connections and wiring errors causing the TC54 voltage detection chips to fail.

The LVC function provides an opto-coupled 2-wire output signal that can be connected into the ebike controller's ebrake input, or can be used to pull down the throttle signal, that goes active anytime a block of paralleled cells goes below 3.0V, for LiPo, or 2.1V for LiFePO4. This will cause the controller to temporarily cut the throttle input, which removes the load. Simple, but very effective and estremely reliable.

Options are provided for either one or two boards, with the latter having the LVC opto outputs already connected. A two-wire pigtail and a 2-pin header connector is provided for each board, or group of boards, which can be used to "daisy-chain" the opto outputs from multiple LVC/HVC/Parallel Adapter boards.

Basic options are for one, or two, LVC boards per PCB-only, plus a full set of illustrated assembly and test instructions. Options are also provided for a full kits, for one or two LVC boards. The links below are for Bill of Materials (BOM) Word files that have links to all the parts:

8s LVC BOM

A complete set of illustrated assembly, test and connection intructions is provided here:

6s-8s LVC Assembly, Test and Connection Instructions

A partial kit option is provided, which includes all non-Mouser parts, in addition to the PCB(s).

New
HVC-Limited Charge Controller - v4.0.8.
The charge control logic works in conjunction with the HVC opto signal from the LVC/HVC/Parallel Adapter boards, to ensure that no cell is allowed to go over the HVC set point (4.16V for LiPo; 3.62V for LiFePO4). There is also an adjustable low current auto-shutoff feature that uses a trim pot to set low current trip point. The Charge Controller uses the opto-driven HVC signal to modify the duty cycle of a pulse width modulation (PWM) circuit that "throttles" the current in order to keep any cell from exceeding the HVC set point. In effect, separate CV modes for each channel.

The Charge Controller is simply inserted between the supply and the pack to be charged and the HVC opto signal is connected. There is a "Start" button and a single LED on one end of the unit. Once the "Start" button is pressed, the LED will be red, to indicate the CC mode is active. Once the 1st cells hit the HVC point, and the throttling begins, the LED will be orangish in color, but will transition to green, once the cells start getting full, and the current drops (CV mode). Once the current drops to about 180-200mA, the cells are about as full as they will get and the LED will be fully green. Once the current drops below the value set with the trim pot, an auto-shutoff circuit will cut the charge current and shut off the Charge Controller. The set point is adjustable from 0 to about 2.5A. As an added safety feature, this circuit will also shutoff the Charge Controller should the supply current be cutoff prematurely, for some reason. This will prevent the Charge Controller logic from draining the pack.

There are several configuration choices, a "barebones" PCB-only option, that includes detailed assembly/test instructions; a partial kit of the PCB + all non-Mouser items; and a complete kit. Included with all options are the custom end plates for the Hammond extruded aluminum case. The links below are for a Bill of Materials (BOM) Word file that has links to all the parts; and a link to the assembly/test instructions:

Charge Controller BOM

Charge Controller Assembly & Test Instructions

Both kit options include the pushbutton switch, with a length of two-conducter hookup wire; a set of 14-gauge input and output wires; and a set of JST/BEC pigtails for the HVC opto signal.

New
Battery Medic Balancer 1A+ Booster Unit.
The versatile Hobby King Battery Medic balancer works very well to accurately discharge/balance LiPo packs, usually to within 4-5mV. The only problem with these RC-type balancers is that they are only designed to typically be used with capacities of 5Ah, or less. Most only provide balance currents of 200-300mA, max. The Battery Medic actually has 350-400mA shunt circuits, but these are "pulsed", 2 seconds on, and then 1 second off, in order to better manage the heat. A typical ebike pack, with a capacity of 10-20Ah, can take quite awhile to balance, with shunt currents this low.

The Battery Medic Booster addresses this problem by simply boosting the shunt current by an extra 1A+. There is a simple mod that is done to the bottom of the Battery Medic's lower PCB, to bring out six small signal wires. The Booster uses these signals to turn on a large shunt transistor through a pair of 3W resistors, whenever the Battery Medic's shunt is on for that channel. An orange LED is also lit, whenever the shunt for that channel is on, to provide a visual indication. The extruded aluminum box also has two small fans at one end that are automatically turned on if the shunt resistor temps exceed 45C. The Booster operation is automatic, and completely controlled via the Battery Medic.

Configuration options include a PCB-only version, but with a full set of assembly and test instructions, and a partial kit, which includes the PCB + all non-Mouser items. Also included for both options are the custom end plates for the Hammond extruded aluminum case. The links below are for a Bill of Materials (BOM) Word file that has links to all the parts, and for a detailed and illustrated set of assembly and operating instructions

Battery Medic Booster BOM

Battery Medic Booster Assembly & Operating Instructions

The partial-kit option includes the 7-wire JST-XH output pigtail for connection to the Battery Medic and the required lengths of 24 AWG multi-colored hookup wire.

Black PVC Shrink Wrap Tubing.
Extra-wide, 9-3/4"/248mm high-quality black PVC shrink tubing. Perfect for making 3p/15Ah or 4p/20Ah LiPo packs. 2:1 shrink ratio.

New
3-Speed Hub-Compatible Freewheel Adapter Kit
Allows a standard BMX 1.37" 24 TPI freewheel to be used in conjuntion with a larger, independent motor-driven sprocket on a Nexus, SRAM or Sturmey-Archer 3-speed hub. Having a "second" freewheel in back eliminates the need for installing a special freewheel-equipped crankset, so that the motor doesn't drive the pedals, when it is on. Four holes are provided in the adapter base that match up to a standard 16T 3-splined Nexus cog (not supplied...). The steel cog is then sandwiched between the freewheel adapter and the motor sprocket/adapter, using the supplied stainless steel button-head screws, nuts and lock washers, along with the supplied black-anodized aluminum spacers/standoffs. This assembly fits on the splined hub and is held in place with the standard circlip, provided with the hub. Then, a standard BMX-type freewheel, which are available with 16-22 teeth, is screwed onto the feeewheel adapter. This adapter is compatible with all popular 3-speed hubs, including Nexus, SRAM and Sturmey-Archer.

Kit includes the adapter, four stainless steel 1/4-20 x .75" buttonhead scews, with lock washers and low-profile stainless steel nuts, and the required washers/spacers. In addition, four linger 1/4-20 x 1" screws and four anodized aluminum standoff spacers are also provided, which allows for various chainline options for the motor-driven sprocket.