Few weeks ago my DJI Go 4 app prompted me to update firmware to the latest version. I did it using DJI Go 4 app. Version is 01.00.0900.
I than took Spark for some flights going through 3 batteries (no complaints about firmware mismatch even though I updated Spark with one battery only).

Later I saw some discussions on this forum suggesting that latest firmware update for Spark is for both AC and batteries.
I also saw several forum members suggesting to use DJI Assitant 2 for upgrade.

I downloaded latest version of DJI Assistant 2 (V1.1.6) on my Windows 10 PC and connected Spark to check firmware status. There was no information about battery firmware, only AC firmware - see picture below:

It simply lists version V01.00.0900 as current version.

When I go to general settings in DJI Go 4 app and choose "About", I see that AC firmware is at V.01.00.0900 and RC firmware at 01.00.0400. No information (that I could find) on battery firmware.

Perplexed, I start changing my batteries to ensure that each one is matching the AC firmware. Sure enough DJI Go 4 app discovered that out of 3 batteries I have, two have firmware mismatch. This is not surprising because when I updated firmware few weeks ago, I did it to Spark with one battery only having no idea that other batteries need to be updated - DJI Go App said nothing about what it was updating and displayed no warning that battery firmware needed updating. What is surprising though it let me fly on these unupdated batteries with no problem. Only today, when, prompted by forum articles I downloaded DJI Assistant to check battery firmware, DJI Go 4 app protested, displayed firmware mismatch and aksed to update. It did it for both unapdated batteries.

So here are my questions: How can I know that batteries need updating when DJI Go App says nothing but simply updates firmware to something (AC? Batteries? RC?)? How do I check battery firmware? DJI Assistant does not show it (at least I can't find this info) and DJI Go App does not show it either.

Some forum members suggested using DJI Assistant to update battery firmware going through all batteries. How? In DJI Assistant I see only a list of AC firmware updates and not battery firmware.

Also - where can I find DJI Asisstant 2 manual - does this exist or it is unsupported software?

Hi, Mirek. I would recommend you connect your spark with phone and check if the battery firmware is the latest one. You can enter general setting- about to see that. If the firmware is the latest one. Here is the release note for your reference.

Hi Elektra. I am confused. Where do I see battery firmware version?
As I mentioned in my post above, I did enter General setting / About on my DGI Go 4 app and I did not see the battery firmware information there. I see AC and RC firmware versions and I see version of DJI Go 4 app. Basically, it lists what you are listing in the picture you attached in your post. Your picture does not show battery firmware version either. Where is this information?

Why can't DJI list the battery firmware release version too?

The firmware update process is basically a game, until the app is 'happy'.

DJI Elektra Posted at 2017-12-29 18:52
Hi, Mirek. I would recommend you connect your spark with phone and check if the battery firmware is the latest one. You can enter general setting- about to see that. If the firmware is the latest one. Here is the release note for your reference.

Hola Elektra, hablas español?

I had the same issues, 5 batteries and only one had current firmware, only way I got all to the same F/W was assistant 2, and installed one battery after the other. Then all 5 showed current in battery info on the app.

djiuser_XHQT2ku Posted at 2018-1-1 18:27
Hola Elektra, hablas español?

Hi, sir. Sorry that I can not speak Spanish. Please write down your question in English.

DJI Elektra Posted at 2018-1-4 23:22
Hi, sir. Sorry that I can not speak Spanish. Please write down your question in English.

Hola Elektra, puedes usar Google Translator para traducir al ingles mi consulta, así como lo hago yo ahora en respuesta a tu solicitud
Hello Elektra, you can use Google Translator to translate my query into English, just as I do now in response to your request

Mi problema es que luego de un tiempo de no usar mi Spark ahora la aplicacion DJI Go 4 de mi Tablet Android o de mi telefono Motorola
Moto G6 Plus no se conecta al drone. Cuando lo deje de ocupar funcionaba normalmente.
My problem is that after a while of not using my Spark now the DJI Go 4 application of my Android Tablet or my Motorola phone   Moto G6 Plus
does not connect to the drone.  When I stopped using it, it was working normally.

Resetee la password del Wi-Fi del Spark, enlace el control remoto nuevamente con el drone, pero la aplicación DJI Go 4 sigue sin comunicarse
con el Spark. Estoy conectando el control remoto al telefono usando un cable OTG.

I reset the Spark Wi-Fi password, pair the remote with the drone again, but the DJI Go 4 app still doesn't communicate   with the Spark.
I am connecting the remote to the phone using an OTG cable.

Hola Elektra, puedes usar Google Translator para traducir al ingles mi consulta, así como lo hago yo ahora en respuesta a tu solicitud
Hello Elektra, you can use Google Translator to translate my query into English, just as I do now in response to your request

My problem is that after a while of not using my Spark now the DJI Go 4 application of my Android Tablet or my Motorola phone   Moto G6 Plus
does not connect to the drone.  When I stopped using it, it was working normally.

I reset the Spark Wi-Fi password, pair the remote with the drone again, but the DJI Go 4 app on muy phone still doesn't communicate with Spark using OTG cable.
DJI Go 4 Version 4.3.37

EduardoAug Posted at 8-26 13:00
Hola Elektra, puedes usar Google Translator para traducir al ingles mi consulta, así como lo hago yo ahora en respuesta a tu solicitud
Hello Elektra, you can use Google Translator to translate my query into English, just as I do now in response to your request

Hi Eduardo,

Careful, Google services like Translator are most probably not available in countries like China.
Anyway, your problem could be connected to a recent OS upgrade of your phone. This is often an issue with DJI Go 4 app, unfortunately.

Cheers,
Wolferl