Alteration of a multimeter on Li-Ion with charging

Most hams, including myself, faced the problem of how to leave the multimeter turned on for a while and forget about it, which ultimately leads to frequent replacement of the crown due to low discharge. In this case, it’s easy to solve this problem with power.

Materials and tools

Materials:
Alteration of a multimeter on a li-ion with charging
Tools:
  • Soldering iron (solder, flux).
  • Glue.
  • Knife.

Alteration of a multimeter

To begin, I took apart a multimeter , and decided on the location of the components in the case.
Alteration of a multimeter on a li-ion with charging
On the lid itself, with the help of side cutters, I cut off the protruding part, on which the battery will be attached.
Converting a multimeter to li-ion with charging
Pre-accumulate the battery before charging,I did this using the same controller.
Alteration of a multimeter on a li-ion with charging
The voltage on a charged battery should be about 4.2 volts. It is advisable to take a battery with a good capacity, in my case it is 1100 mah.
Alteration of a multimeter on a li-ion with charging
I soldered the battery “+” and “-” to the battery, you need to solder very quickly, because the batteries cannot be overheated.
Alteration of the multimeter on li-ion with charging
Then I cleaned the cover and glued the battery to it with thermal glue.
Alteration of a multimeter on li-ion with charging
I soldered the positive or negative wire to the input of the converter.
Alteration of a multimeter on a li-ion with charging
And I soldered any of the remaining wires to one of the contacts of the switch, and from the switch I had already soldered to the battery. The switch is needed to ensure that the converter does not work in idle mode.
Alteration of the multimeter to li-ion with charging
Next, I set the voltage on the converter,which should be at least 9 volts.
Alteration of a multimeter on a li-ion with charging
Then I soldered the standard power wires from the board.
Alteration of a multimeter on a li-ion with charging
Instead of standard wiring, I soldered the output of the converter, observing polarity.
Alteration of a multimeter on a li-ion with charging
Then I glued the transducer to the place where I used to have a crown. img src="https://sdelaysam-svoimirukami.ru/uploads/posts/2018-02/medium/1519128660_13.jpg" style="max-width: 100%;" alt="Converting a multimeter to li-ion with charging">
On the front panel I will install a switch, for him I cut out such a window. The switch can be installed from the side, but it will not be convenient.
Alteration of a multimeter by li-ion with charging
Next, I glued it on a second glue.
Alteration of a multimeter on a li-ion with charging
I made a hole near the display for the battery charging board, and it would be even better to make a hole for indication.
Alteration of the multimeter on li-ion with charging
I also glued the controller to the second glue with the addition of soda. In parallel with the controller, I soldered the wires to the battery.
Alteration of a multimeter on a li-ion with charging
That's all a multimeter with a battery inserted is ready, and now you will lose such a problem as replacing a crown. And another big plus is that if you, for example, measure only one voltage, then you do not need to switch to off mode, since there is already a built-in switch.