SparkFun 5V/1A LiPo Charger/Booster Hookup Guide

Contributors: MTaylor
Favorited Favorite 6

Hardware Assembly

It's easy to get started on your bench. Simply plug the LiPo into the battery JST connector, charge with a micro-B USB supply, and solder your load to the output pins. This section shows some tips and alternate ways to configure the ports.

Connecting to the Charge and Battery Ports

(top) Without modification, the charger and battery can be plugged straight in. (bottom) Connections can be made to one or both of the battery/charger ports by way of soldering wires into the provided holes.

Covered Battery Pins

There are a pair of through-holes peeking out from underneath the JST connector. Here's how to safely remove the JST and apply battery leads directly. This also lowers the profile of the circuit board.

Make several small cuts to split the JST housing using a cutter. If you try and take the whole thing off at once, you risk pulling up the pads.

Cutting the JST Housing

Splitting the top off the JST connector.

With the top removed, the pins aren't captured in the housing anymore and they can be pulled off with the soldering iron one by one.

Remove JST Pins

Unsoldering the pins

Alternatively, you can hot air the JST connector off, but it may melt in the process.

Caution: When working with a live battery where voltage is always present, don't cut both leads at the same time! This will short out the battery and damage the cutters. Work with each wire individually.

Cut and strip part of the end of the wire. Then solder the end to its respective through hole.

Soldering Ground Wire

Connecting the first wire

Solder Second Wire

Connecting the second wire

Charge Source Pins

As with the JST port, you may wish to charge your lipos from a source other than a micro-B, such as a 5v barrel or bench supply. The USB port is difficult to remove without damage to the board, so leave it in and just use the '+' and '-' pins provided by soldering some hookup wire to the respective pins. To connect to a barrel jack easily, you could use a female barrel jack adapter.

Heads up! Never supply two power sources for charging at the same time!

Connecting to the Charge Source Through Hole Pins

The charger booster with a barrel jack attached.

External Switch Pins

The onboard switch is rated for 600mA. Using the full current output available, this rating will be violated. It won't have any immediate effect and is alright for peaky load with a nominal 500mA draw, but can lead to heat and corrosion depending on your application. If it's found to be a problem, solder a higher current switch (like the SPST rocker switch) into the 'EXT SW' pins.

High Current External Switch

A high current capable panel switch is used to bypass the on-board switch.

Using a high current switch, the two switches are now in parallel so either one can be used to energize the circuit. If using an external switch, be sure to leave the on-board switch in the OFF position.

Or you can jumper the external switch pins together and use the enable pin to switch power. Further details will be explained in the next section with the enable pin.

Enable Pin

Another method to remove battery load is to use the enable pin on the PAM2401. It's pulled up with a resistor on the board, so leaving it floating will default to an enabled state. To disable, it can be connected to the neighboring ground pin. The pin consumes very little current so a light duty switch (like the mountable slide switch) can be used.

Enable Pin with Switch

A small switch can be used to disable the booster.

In this configuration, the onboard switch may not be necessary and can be bypassed by putting a jumper in the external switch holes. The battery won't be truly isolated though, and can drain over time. In the disable state, the current draw from the battery is about 6uA so it should take years to discharge.

Alternately, the pin can be driven by a logic source. The pin is 6V tolerant, with a logic-high threshold at 1/2 battery voltage, and a lower threshold of 0.2V.