There are two types of breaker in the box.
The individual circuit breakers are overload devices of various capacities. For a circuit of sockets (UK)it is likely to be 32A, but could be 16A. This will only trip under overload conditions such as a short circuit.
The other device is wider and covers a group of circuits. This is called an RCD (residual current device) and monitors the live, neutral and earth. If there is any imbalance between the input and return into this device, it will trip.
I suspect it is this one tripping and it is merely doing it's job, you do not need necessarily a new one.
RCD's will trip if there is a neutral to earth fault - as is likely here.
If it is only tripping when you plug the charger in then this is the suspect device. As you've ordered a new one just wait and try it. If the problem goes away then it's likely the cause.
If it trips with the new one then further investigation is needed. But a new RCD will not cure it - it's just telling you something is amiss, that's it's job.
An RCD is there to prevent electricity taking the wrong path, via a human for example, to ground.
It only monitors Phase and Neutral currents, but not earth, as there is simply no need to monitor earth (won a few pints over the years from Electricians in pubs with that statement!), for any reason at all!
What an RCD does, is it compares the phase current, against the neutral current, which when working correctly, must be opposite, but otherwise equal & identical. Thats how things should work.
If they are not identical, then the power has found a new way back to earth, this causes the breaker to almost instantly to drop. From memory, 30 msecs or so. It is still quite painful though, even though it is most unlikely to kill anyone, but if there is someone super sensitive, there are lower current value RCDs on the open market if required.
I remember my Father and I rewiring my then UK abode, a 15 Century double house, in 1977, and he recommended one of these devices, which were I believe, not in many houses at that time.
It was particularly good at detecting that the kettle needed a new element (porous), and other than my step son, pressing the test switch occasionally, it was fine. (they need to be tested regularly anyway, once a year is a memory......)
i do remember that the very early ones operated slightly differently than the ones made over the last 40 years or so, but I do not remember what that difference was anymore, and those early versions should have been replaced long ago.
Also, please remember that RCDs themselves, do not detect or prevent current overloads, so years ago you needed normal breakers for the current overloads and an RCD for each phase, usually only one phase in the UK. Here we have all three!.
Nowadays, there are also combination breakers that trip at a specific overload, and if the current gets unbalanced, it also trips.
Either fault type simply dropping THAT breaker only, the one that is affected.
And guessing only, no single large RCD legally required on each phase, unless some circuits are still not fully protected against electrocution.
I tripped one once giving a class in a classroom with no windows, and here in Germany, there is no separation of power sockets and lighting, so not only did I get a shock, but I also had to fumble my way to the door to let some light into the classroom, and then go and find the breaker to reset!!
Nowadays I would hope that it is a requirement for all houses to have at least one main RCD per phase.
It is still quite recent here and only since around 2010...
If anything needs further explanation, just let me know.
regards
Andy