A memóriakártya tele van, és a töltöttség megfelelő.

In Hungarian, tele and van work together as a set expression:

• tele = full
• van = is

So A memóriakártya tele van literally feels like The memory card is full.

This is a very common pattern:

• A pohár tele van. = The glass is full.
• A szoba emberekkel van tele. = The room is full of people.

So even though English uses one adjective, Hungarian often uses the expression tele van.

This is a very important grammar point.

In standard Hungarian, in the present tense, third person, the verb van is usually left out when the predicate is a noun or adjective:

• A töltöttség megfelelő. = The charge level is adequate.
• not usually: A töltöttség megfelelő van.

But tele van is an exception-like fixed expression. Hungarian normally says:

• tele van = is full

So:

• A memóriakártya tele van.
• A töltöttség megfelelő.

That difference is normal and idiomatic.

Töltöttség means something like:

• charge level
• state of charge
• how charged something is

It comes from the verb tölt = to fill / to charge, plus the noun-forming ending -ttség / -ség, which creates an abstract noun.

So:

• tölt = charge/fill
• töltött = charged, filled
• töltöttség = charge level / degree of charge

In technical contexts, especially on devices, töltöttség is a natural word for battery charge status.

A is the Hungarian definite article, meaning the.

So:

• a memóriakártya = the memory card
• a töltöttség = the charge level

Hungarian uses the definite article very often, including in many cases where English also uses the. In a device message, both items are understood as specific:

• the memory card in the device
• the relevant charge level

So the definite article sounds natural here.

Yes. Hungarian very often forms compound nouns as a single word.

So:

• memória = memory
• kártya = card
• memóriakártya = memory card

This is extremely common in Hungarian. English often writes these as two words, but Hungarian tends to join them:

• bankkártya = bank card
• hitelkártya = credit card
• szemüvegtok = glasses case

This is the most neutral, straightforward word order.

Hungarian often starts with the topic, then gives the comment about it:

• A memóriakártya → topic
• tele van → what is being said about it

Then the second clause does the same:

• a töltöttség → topic
• megfelelő → comment

So the sentence is basically:

• As for the memory card, it is full, and as for the charge level, it is adequate.

That is very normal informational word order in Hungarian.

Yes, but the meaning changes slightly.

• A memóriakártya tele van. = The memory card is full.
  This describes a current state.

• A memóriakártya megtelt. = The memory card became full / has filled up.
  This emphasizes the change or result.

On a device screen, tele van is often better if the message is simply describing the current status.

Megfelelő means:

• adequate
• suitable
• appropriate
• acceptable

It is a bit more formal or technical than simply good (jó).

So in a device message, A töltöttség megfelelő sounds like:

• The charge level is adequate
• The battery level is sufficient
• The charge status is OK

It fits the tone of system or technical language well.

Because the sentence is talking about the level of charge, not the battery itself.

Compare:

• akkumulátor = rechargeable battery
• elem = battery/cell
• töltöttség = charge level

So:

• Az akkumulátor megfelelő. would mean The battery is adequate/appropriate, which is a different idea.
• A töltöttség megfelelő. means The battery charge level is adequate.

In technical Hungarian, this distinction matters.

A simple pronunciation guide:

• memóriakártya ≈ meh-MOH-ree-yah-KAAR-tyaw
• töltöttség ≈ TURL-tutt-shayg

A few useful pronunciation notes:

• ó is a long o
• á is a long open a
• ö / ő are front rounded vowels, a bit like German ö
• ty sounds like a soft t, somewhat like the t in British tune
• cs = ch
• s = sh
• sz = s
• gy is a soft sound somewhat like dy

If you want, I can also break the whole sentence down word by word with pronunciation and grammar labels.