Als het lampje blijft knipperen, is de batterij bijna leeg.

Als introduces a condition or situation.

In this sentence, als is best understood as if:

Als het lampje blijft knipperen, is de batterij bijna leeg.
= If the light keeps flashing, the battery is almost empty.

In some contexts, als can also be translated as when, especially when something is expected to happen. But for warnings or instructions like this, English usually prefers if.

Lampje is the diminutive form of lamp.

• de lamp = the lamp / light
• het lampje = the little lamp / small light / indicator light

In practical everyday Dutch, het lampje often refers to a small indicator light on a device, not necessarily a literal tiny lamp. So here it most likely means the indicator light.

Also notice that diminutives in Dutch always take het:

• de lamp
• het lampje

Because lampje is a diminutive, and all Dutch diminutives take het as their article.

So:

• de lamp = the lamp
• het lampje = the little lamp / indicator light

This is a very useful rule:

• words ending in -je, -tje, -pje, -etje, etc. are usually diminutives
• diminutives are always het words

This is a common Dutch structure: blijven + infinitive.

It means to keep doing something or to continue doing something.

• blijven = to stay / remain
• knipperen = to flash / blink

So:

• het lampje knippert = the light flashes
• het lampje blijft knipperen = the light keeps flashing / continues flashing

This works like English keep + -ing, but Dutch uses blijven + infinitive instead.

Because the first part begins with als, which creates a subordinate clause. In Dutch subordinate clauses, the verbs usually go to the end.

So:

• main clause: Het lampje blijft knipperen.
• subordinate clause: Als het lampje blijft knipperen...

That final position for the verb is very normal in Dutch after words like:

• als = if
• omdat = because
• dat = that
• terwijl = while

So the order here is not unusual—it is standard Dutch grammar.

Because when the sentence begins with the als clause, the main clause follows the Dutch verb-second rule.

Basic main clause:

• De batterij is bijna leeg.

But when another element comes first:

• Als het lampje blijft knipperen, is de batterij bijna leeg.

So after the comma, the conjugated verb is must come before the subject de batterij.

This is a very important Dutch pattern:

• Vandaag is hij thuis.
• Als het regent, blijf ik binnen.
• Na het eten gaan we weg.

The finite verb comes second in the main clause.

Knipperen can often be translated as blink or flash.

For an indicator light, English speakers often say:

• blink
• flash

So het lampje blijft knipperen means:

• the light keeps blinking
• the light keeps flashing

Flicker is possible in some contexts, but it often suggests an unsteady or irregular light, so it is not always the best choice for a battery warning light.

Literally, it means almost empty.

• bijna = almost
• leeg = empty

So:

• de batterij is leeg = the battery is empty / dead
• de batterij is bijna leeg = the battery is almost empty / nearly dead

With batteries, English often says the battery is almost dead, even though Dutch uses leeg (“empty”).

Because batterij is grammatically a common-gender noun in Dutch, so it takes de:

• de batterij

Unfortunately, for many nouns you simply have to learn whether they take de or het. There is not always an obvious reason.

In this sentence:

• de batterij = the battery

Unlike lampje, it is not a diminutive, so it does not automatically become a het word.

Yes, the comma is standard here.

Dutch usually places a comma between a subordinate clause and the main clause when the subordinate clause comes first:

Als het lampje blijft knipperen, is de batterij bijna leeg.

This is similar to English: If the light keeps flashing, the battery is almost empty.

So the comma helps separate the condition from the main statement.

Grammatically, wanneer means when, and it can sometimes introduce similar clauses. But in this sentence, als is more natural because the sentence expresses a condition.

• Als het lampje blijft knipperen... = If the light keeps flashing...

Using wanneer would sound more like when in the sense of at the time that, which is less natural for this kind of warning message.

So als is the best choice here.

Then the main clause would keep normal word order:

De batterij is bijna leeg als het lampje blijft knipperen.

That is also grammatical.

Compare:

• Als het lampje blijft knipperen, is de batterij bijna leeg.
• De batterij is bijna leeg als het lampje blijft knipperen.

The meaning is basically the same, but the first version is often more natural for instructions or warnings because it puts the condition first.