Triple 5mA battery trickle charger
Triple 5mA battery trickle charger ——————————————————————————–

This is a 5mA lead acid battery trickle charger along with its case. It works with any battery up to 35V. You can maintain alarm system, motorcycle, caravan, batteries. The input voltage of the device must be below 40V. The input voltage must be 4 V above the battery voltage. This project will maintain the battery while in storage. It’s not a battery charger. The battery must be fully charged before using this device.

This project should cost you less than $10. TO-220 LM317 are shown on the picture because I had them on hand. TO-92 LM317 can be used safely. You can increase the constant current by lowering the resistor. You may need to beef up the power capability of some of the components.

You will need the following to build this project:

  • One 4 cm x 6 cm perforated prototyping board
  • Four KF301-2P terminals
  • One 330uF, 50V radial capacitor
  • Three LM317 adjustable voltage regulators (TO-92 will work)
  • Three 240 ohm resistors, 1/4 W
  • Three 1N4001 diodes
  • Basic electronic tools, including soldering iron and so on.
  • Some glue to assemble the case.

Each charger should be plugged to one battery. Plug the positive pole of a battery to the positive pole of one of the charger. Plug the negative pole of the battery to the negative pole of the charger.

Support material is not required. An infill of 20% is recommended.

This object was designed using Solid Edge Community Edition.

Printable Files

  Base of the case
  Cover of the case

This object is also published on the following site(s):
Prusa Printers

The source files are available:

You may request the source file(s) of this object. Ask for it by posting a comment below. Your email address will NOT be used for any other purposes than delivering you the source files. By doing so:

You are free to:

* Share — copy and redistribute the material except the source files in any medium or format
* Adapt — remix, transform, and build upon the material

You agree to:

* give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
* not use the material for commercial purposes
* distribute your contributions under the same license as the original if you remix, transform, or build upon the material
* not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
* not upload the source files or modified source files on any sites. They are made available for your personal usage only. Nevertheless, you are allowed to upload the resulting STL or OBJ files.

If you do not agree to any of these conditions, do NOT request the source files.

Copyright 2012-2023 by Claude “Tryphon” Théroux

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