Malahit DSP2 – 2 x 18650 with BMS guide

The Malahit DSP2 has no internal protection, because the current is very low. I installed a BMS for a protection, because i want to protect the Malahit DSP2 for defective 18650 cells. Even if you want to make a mod with 2 18650 cells, it´s would be a good idea.

The Malahit DSP1 / DSP2 is using the TP4056 charging controller, with this specifications:

  • charging current: 0,9 A
  • input voltage: 4,5 V – 5,5 V
  • charging end voltage: 4,2 V

You can charge 2 x 18650 cells in parallel conenction with this controller, but i takes twice as long as before.

What are the features of a BMS?

  • overcharge charge voltage protection (for Li-Ion mostly 4,25 V with + – 0,05 V)
  • undercharge voltage protection (for Li-Ion mostly 2,5 V)
  • maximum continuous current (more MOS, more current)
  • overcurrent detection (short circuit too)
  • reverse protection
  • and some more

Which kind of BMS do you need?

You need a BMS with the specifications:

  • 1S (for parallel connection)
  • For Li-Ion (only with that, the BMS have the correct overcharge, undercharge, etc. specifications)
  • Current with 2 A is more than enough for the Malahit DSP1 / DSP2

What kind of 2 x 18650 cell holder do you need?

You need a cell holder with this specifications:

  • Use a cell holder, which is not much longer and heigher, than the 18650 cell. All cell holders on the pictures are ok from the size for the Malahit DSP2
  • Use a parallel cell holder, both cells must be in the same direction. A seriell cell holder have two diffrent directions of the cells, like the holder in the middle. The cell holders on the left and right must be soldered parallel first, because they have no connections between the cells.
  • No soldering flags outside at the bottom and at the side. For the cell holder left and right, you have to shorten the soldering flags on the bottom, that they can´t reach the Malahit case

1S BMS soldering diagram

Here you can see a diagram of a standard 1S BMS for a Li-Ion cell:

  • B+ / B- to the 18650 cell or cells
  • P+ / P- to the cable of the Malahit DSP2

How to install the BMS in the Malahit DSP2

This is a 2 x 18650 cell holder (a 1 x 18650 cell holder is possible too), with a simple 1S BMS. The BMS can be glued with the other side to the holder.

Pay attention to the soldering flags that stick out at the bottom and sides of some battery holders. If they can be connected to the case of the Malahit, you have to shorten them before. If the cells are shorten with the case, only the BMS can safe you from degasing,

The battery holder has no connections between the cells, this is the reason why i used 2 wires from each site to the B- / B+ sodlering flags. Most holders have only 1 wire, because they hab connections between the cells already soldered.

  • B+ / B- to the 18650 cell or cells
  • P+ / P- to the cable of the Malahit DSP2

Top view without connection to Malahit:

Another view from the top, glued with a tape and connection wires soldered to the Malahit DSP2:

Take care that the sides of the cell holder have no connection to the case. The easy solution is to use isolation tape, but i glued it with epoxy before.

I had to move the speaker to the left and set the cell holder so near it is possible to the speaker. Another solution can be, to glue the cell holder horizontally in the case.

I is a good idea to isolate the contacts on the BMS. Simle with isolation tape or use Epoxy. I used both, but forget to make pictures of the epoxy.

If you use 2 x 18650 cells

At first: The TP4056 charging controller of the Malahit can charge 2 x 18650 cells at the same time, if you use them parallel. But if you want to use 2 x 18650 cells, you have to know some thing.

  • Only use parallel connection (if you use a seriell connection, the voltage adds up with every cell and whith that, the Malahit DSP1 / DSP2 is not compatible)
  • Only use cells from the same type, if the cell have to much difference, it can be dangerous
  • If you want to be on the safe side, measure the internal resistance of the cells and using 2 cells, with almost the same internal resistance

At the first time of use, charge the two cells to the end, before you put them in the cell holder (if not the balancing current can be very high and harms the cells or the Malahit)

Where to buy the parts?

I use the smaller 2 x 18650 cell holder and the 5A 1S Li-Ion BMS:

Malahit DSP2 – Firmware History

Malahit DSP2 – Firmware download

I have received permission from Georgiy to upload the firmware to my server. You can download ist here:

Malahit DSP2 – Firmware – Changelog

Here you can find the changelog: Changelog (Перечень изменений) – Google Docs

Malahit DSP2 – Firmware Changelog – Test 2.10 24.07.2021

  • fixed battery voltage indication
  • fixed behavior of encoder buttons at low supply voltage
  • protection against false switching has been made – for switching on by three, set switch 2 to the On position.
  • added test function – increased display frequency. This reduces noise and increases the number of frames per second; To enable this function, set switch 3 to On. The function may not work correctly, if so, please let me know
  • the level of interference from the display is slightly reduced
  • changed the distribution of frequencies to which the input high-pass filters are turned on
  • when HiZ is turned on, the power supply of the external active antenna is automatically turned off;
  • added indication of external antenna power on – now the ANT indicator is highlighted in red if this function is enabled
  • the algorithm for displaying the picture on the display, slightly reduces the level of interference
  • changed the panorama display mode from “Pan & WTF Disabled / Enabled” to “Pan & WTF Single / Always”, while the panorama image is now always present, but it is updated once (when the settings are changed) or always.
  • fixed attenuators bugs

Malahit DSP2 – Firmware Changelog – Test 2.10 SAM 31.07.2021

  • SAM functionality

Malahit DSP2 – Firmware Changelog – Test 2.10 13.08.2021

  • corrected voltmeter operation
  • added SAMU, SAML modes
  • increased interface display frequency
  • improved switching between menus – now it does not pause
  • optimized the WFM algorithm, the receiver began to work faster
  • improvements made to Pan & WTF Single mode
  • removed graphical artifact near the SQL indicator

Malahit DSP2 – Firmware Changelog – Test 2.10 16.08.2021

  • improved suppression of interference from the display. Now in SSB, AM, NFM modes, noise reduction is automatically turned on. This slows down the speed of the user interface, but greatly reduces the clutter! This function is not used in WFM mode.

Malahit DSP2 – Firmware Changelog – Test 2.10 17.08.2021

  • Waterfall bandwith increased from 160khz to 192khz

Malahit DSP2 – Firmware Changelog – Test 2.10 25.08.2021

  • added Pseudo Stereo function. Added Pseudo Stereo button to Audio menu
  • added the ability to switch audio output in the HARD menu – added the Audio out button. Ph + Sp – headphones and speaker, Phone – headphones, Speaker – speaker
  • added PGA BST function to HARD menu. This function can be useful when receiving strong signals and receiving congestion. When overloading, you must select the Disabled position.
  • changed the arrangement in the frequency bar under the spectrum
  • changed the behavior of the receiver with a short press on the power button. Now, with a short press in the receiver, the touchscreen is turned off, the spectrum and waterfall work similarly to the Pan & WTF Single option.
  • the lower operating frequency has been reduced from 50 kHz to 20 kHz.

Malahit DSP2 – Firmware 2.10 Test – New options

You can activate two experimantal fuctions, which less interferences fro the TFT, more FPS on the screen and a new power on mode.

  • Switch 2: The receiver power on with 3 pushes on the power button (for me it takes 5 pushes), without only one push is needed
  • Switch 3: Added in test firmware from 24.07.2021, but don´t need to be activated in the last firmware from 16.08.2021, because it´s default activated

Malahit DSP2 – Mods which are in work

Currently I am working on some mods for the Malahit DSP2. But before I recommend something concrete, I would like to do tests with different variant to really find the best components.


In the moment i make some tests with Bluetooth boards. The left one is working from 3v to 5,5v and is perfect for the 18650 cell. The little right one has the lesses interferences.

BNC Socket

I found a very good BNC socket, which is only a bit bigger than the SMA socket. The other BNC jacks I’ve had were extremely large in circumference, which would have meant that the hole for the jack would no longer stay on one side of the Malahit DSP2’s case. The new socket solves the problem and is still high quality.

Only the hole for the socket must be a little bit bigger. With the U.FL port the rest is no problem and plug and play.

SMA Sockets

I make some test with other SMA to U.FL connectors. Some of them are making much interferences. The right one is the best one. All have the same diameter and can fit into the SMA socket hole of the Malahit DSP2.

BMS and 2 x 18650 cells

At the moment i test some 18650 cell holder and BMS. I already use a external BMS and 2 x 18650 cells in my Malahit DSP2.

Also there are many cell holder ons the market. Some of them can fit protected 18650 cells and some of them not.

U.FL Sockets

At some time i thought my U.FL socket is broken. But than i found, that the U.FL port on the SMA cable was broken. If the U.FL bushing does not survive the experiments, I can replace it.

When i finished, i create guides for all of the mods.

Malahit DSP2 – Better Buttons

Nikloay makes very high quality knobs that make the Malahit, much more comfortable to use. I like them very much, and the feeling is very good because of the high quality.

How to buy the knobs?

  • E-Mail to Nikolay, you can write to him in english
  • Niklay now built the buttons and it can take some days
  • When they are finished, you can sent him the money with Paypal. I had to pay 14€ to the EU and 17€ to the USA
  • Shipping taked for me about 7 days to the EU

Picture of the knobs

Malahit DSP2 – What is the best 18650 battery?

At first: The Malahit DSP1 / Malahit DSP2 no built in protection for the 18650 cell, because the current is very low. But the charging controller is good (TP4056) and it comes with some protection features.

TP4056 specifications:

  • charging current: 0,9 A
  • input voltage 4,5 V – 5,5 V
  • charging end voltage: 4,2 V

Some informations about 18650 batterys

18650 cells are a bit dangerous. There are many fakes in circulation and even if you buy from a trusted dealer, you may not get an original. The fakes are often removed from old batteries, for example, from old laptop batteries.

In the worst case, such a battery can degas. Fortunately, the case has holes for the sound, so the case does not explode. But this can cause fire to escape or simply damage the malahit.

How to get a good cell?

  • Buy from a big seller (In Germany
  • If the cell has a capacity of more than 3800 mah, this is technically not possible and the cell is a fake

The Malahit has such a low consumption that any 18650 battery is compatible. You can only deal with the following properties:

  • Manufacturer: The best are Panasonic / Sanyo, Sony / Murata, Samsung, LG
  • Capacity: Use a Cell with more than 3000 mah (but not more than 3800 mah, this cells are fake)
  • Protected or unprotected: Proteced cells can be to high for the Malahit cell holder (Measure the high before, perhaps there are diffrent cell holders in the Malahits)
  • Flat Top, high, solde tags: Flat top cells are best for the cell holder of the Malahit
  • Li-Ion and not LiFePO4 (LiFePO4 has a diffrent voltage range)

18650 cells that i can recommend:

  • Panasonic / Sanyo cells like: NCR18650B, NCR18650GA (Some other manufacturer are using this cells, like Keenpower)
  • Sony Konion / Murata cells like: US18650VTC6


I think we have some options to use for the best setup for all of us.

The easy way:

  • buy a NCR18650B, NCR18650GA cell, flat top and unprotected

Little effort with more protection:

  • find a protected cell which can fit in the cell holder of the Malahit
  • you can change the cell holder to a bigger one

The best way in my opinion with most protection:

  • buy a NCR18650B, NCR18650GA cell, flat top and unprotected
  • use a external BMS

Why a external BMS?

A external BMS can protect the 18650 cell and the Malahit hardware. A external BMS is very cheap and with 4 soldering points, easy to implement. The BMS are very smal and can fit on the cell holder.

Features of a external BMS

  • overcharge voltage protection (for Li-Ion mostly 4,25 V with + – 0,05 V)
  • undercharge voltage protection (for Li-Ion mostly 2,5 V)
  • maximum continuous current (more MOS, more current)
  • overcurrent detection (short circuit too)
  • reverse protection
  • and some more

Examples of external BMS

On the picture can you see diffrent types of BMS. They all have the same features, but diffrent maximum current protection from 2A to 8A. The BMS must be 1S for Li-Ion batterys. The BMS must be in the middle of the Malahit and the 18650 cell.

1S BMS have 4 soldering points:

  • 2 x for the battery + and –
  • 2 x for the consumer (Malahit) + and – cable

Here you can see some examples:

  • Malahit with Panasonic NCR18650B cell
  • LG cell with a BMS on top, here you can see that it takes more space (If you buy a proctected cell, the sleeve is over all and you can see the BMS)
  • Some external BMS (More MOS, more current)

In the next days i make a guide how to use a external BMS and how to use 2 x 18650 cell in the Malahit DSP2.

Malahit DSP2 – Holder from Serhii PSB

Serhii PSB built a very very nice Holder for the Malahit DSP1 / Malahit DSP2. You can find his Youtube channel here: Serhii Youtube channel


  • Two versions for Malahit DSP1 and Malahit DSP2 (only original)
  • 2 mm stainless steel
  • addditional surface treatment
  • cutouts at the rear for increased speaker clarity
  • protective pads so that the Malahit DSP1 / DSP2 does not slip or vibrate
  • It’s possible to get a custom text engraved as standard. The names of the Malahit developers are engraved as standard

How you can buy it from him:

  • E mail to Serhii PSB or Telegram to “PSB Serg” in english or russian (Please note that he answer in russian, but it´s now problem to translate it with DeepL)
  • Tell him Malahit DSP1 or Malahit DSP2
  • The price with shipping is in the moment about 35 € because it´s a small batch
  • You can sent the momey with Wester Union or SWIFT bank transfer (He sent it from Ukrain, there is no Paypal)
  • Sent him your full address with country and your mobile phone number

Payment with Western Union (very easy):

You can register a new account for Western Union and it´s very easy and takes only 1 minute. You can sent the money from your bank account or with many other options, to Western Union.

  • There are three options to sent money with Western Union, use the option cash
  • You need only his full name and his telephone number and the coutry Ukraine
  • I had to pay a charging fee from 1,90 € for Western Union
  • After that, sent him the transaction number, than he can go to Western Union an get the money

Paypment with SWIFT bank transfer

A SWIFT bank transfer is more difficult, because you need much of data:

  • Go to your online banking and click on foreign bank transfer
  • You get two IBAN numbers from Serhii: One for $ and one for , please use the correct one
  • Serhii tells you the data which you need like:
    • Serhii: Name, full address
    • Serhii bank: Name, full address, SWIFT code
    • Maybe: Intermediary bank: Name, full address, SWIFT code

I sent him a little bit more money with Western Union, because it is a very nice project and i want to support projects like this.

Here can you see the difference between the Malahit DSP1 and Malahit DSP2 stands:

Malahit DSP2 – CAT control and waterfall to a PC

When you connect the Malahit DSP2 to a Windows 10 computer, you can control it and see a waterfall on it. There are many tools on Windows 10, which are supporting the sound input from the Malahit DSP2.

Tools with sound input and CAT control (Windows 10):

  • SDRUno
  • SDR#

Features which are possible:

  • Waterfall
  • Sync frequency and some settings from the Malahit DSP2 to the PC
  • Sync frequency and some settings from the PC to the Malahit DSP2

In this blog post, i show you SDRUno with OmniRig.

Malahit DSP2 – Driver

For me it wasn´t necessary to install any driver. Windows 10 found the driver by itself. In the Device Manager it should look like this:

Malahit DSP2 – Sound control pannel

Open the Windows 10 sound control panel and then the record tab and activate Malahit spectre – Malahit IQ:

Malahit DSP2 – OmniRig 1.19

At first you must install OmniRig 1.19. With the 2.1 version i had problems. The installation is easy, so i don´t make screenshots from it.

Now you can start OmniRig and configure it like this:

  • Tab: RIG1 (or if you have other receivers connected, pelase note the rig number for SDRUno setup later)
  • Rig type: 480-TS
  • One of the com ports in your device manager (for me it was the second one COM4)

If you make change in OmniRig, SDRUno must be shutdown. If not, it don´t get the new configuration.

Malahit DSP2 – SDRUno

The Installtion is very easy. You can find it here:

Now please start the SDRUno (EXTIO) version, because only in this version, you can change to a audio source:

Now click on the SETT. button:

Now change to the input device of the Malahit DSP2. If you don´t know which of them is the correct, test both:

Click on the RX button on the left side and than on the SETT. button, from the new window:

On the new settings windows click on the tav ORIG and than click on RIG1 and activate all checkboxes:

At last click on the RSYN1 button:

Now you can start the receiving with a click on the PLAY! button:

At the end it should look like this. You can add the two waterfall windows with SP1 / SP2 buttons:

W-FM receiving example

If you now change the frequency or the mode in SDRUno, the Malahit DSP2 should get this change.

Please note: It can take some moment for the synchronisation.

Malahit DSP2 – Reset to default configuration

You can reset the Malahit DSP2 to the default configuration:

  • User configuration will be lost
  • Frequency favorites and band menu will be lost
  • Dynamic Retro Scale custom settings will be lost

To reset the Malahit DSP2 you have to do this:

  • Exit all menus
  • Hold down both encoder buttons until you can hear a beep sound

Now the default configuration should be loaded.

Malahit DSP2 – Waterfall bandwith

On the Malahit DSP2 the waterfall has 3 bandwith options:

  • 160 kHz
  • 80 kHz
  • 40 kHz

To change the waterfall bandwith, tap on the selected area:

Now the waterfall bandwith changes from 160 kHz to 80 kHz.

If you tap another time on the selected area, the waterfall bandwith changes to 40 kHz:

If you tap a last time on the area, the 160 kHz waterfall bandwith came back.

Malahit DSP2 – Set clock

You can set the system clock of the Malahit DSP2. Tap some time on the HARD menu button, until it beeps:

Now you should see this configuration screen:

  • with the small encoder button you can scroll in the selected option
  • click short on the small encoder button, to change the item

You can save the selected time:

  • push the small encoder button until it beeps, now the new time is saved