Luma ang baterya.

This is a very common Filipino sentence pattern. Luma ang baterya is a predicate-first sentence, where the description comes first and the topic comes after.

So the structure is:

• luma = old
• ang baterya = the battery

Literally, it is closer to Old is the battery, but in natural English it means The battery is old.

Filipino often puts the predicate first, especially in simple descriptive sentences.

Ang is a marker that usually points to the topic of the sentence. In Luma ang baterya, the topic is baterya.

So:

• luma = the description
• ang baterya = the thing being described

In this sentence, ang does not mean exactly the, even though ang baterya may often be translated as the battery.

Yes. Ang baterya ay luma is also correct and means the same thing: The battery is old.

The difference is mostly in style:

• Luma ang baterya = very common, natural, conversational
• Ang baterya ay luma = also correct, sometimes a bit more formal or deliberate

Both are good Filipino.

In Filipino, a separate verb like is is often not needed in simple equational or descriptive sentences.

English:

• The battery is old

Filipino:

• Luma ang baterya

So Filipino can express the idea without adding a verb equivalent to is.

No. Luma is usually used for things, not for a person’s age.

Examples:

• luma = old, outdated, worn, aged (for objects)
• matanda = old/elderly (for people)

So:

• Luma ang baterya = The battery is old.
• Matanda ang babae = The woman is old.

Using luma for a person would normally sound wrong unless you are speaking unusually or metaphorically.

Yes, depending on context, it can suggest that the battery is old, worn out, or no longer performing well.

But strictly speaking, luma means old, not specifically dead or empty.

If you want to say the battery has no charge, other expressions may be better, depending on context, such as saying it is ubos or wala nang charge.

So luma ang baterya focuses on age/condition, not necessarily charge level.

By itself, baterya is usually understood as singular: battery.

If you want to make it plural, you usually add mga:

• Luma ang baterya = The battery is old.
• Luma ang mga baterya = The batteries are old.

Notice that luma does not change form for plural.

No, not in this case. Luma stays luma whether the noun is singular or plural, masculine or feminine.

Examples:

• Luma ang baterya = The battery is old.
• Luma ang kotse = The car is old.
• Luma ang mga kotse = The cars are old.

This is much simpler than in languages where adjectives must agree with nouns.

A common pronunciation is roughly ba-te-RYA, with stress near the end.

A rough English-friendly guide:

• ba as in bah
• te as in teh
• rya like ryah

Pronunciation can vary a bit by speaker and region, but that guide will usually be understood.

No. In Luma ang baterya, no linker is needed.

Linkers like na or -ng are used when an adjective directly modifies a noun inside a noun phrase:

• lumang baterya = old battery

But in your sentence, luma is the predicate, not directly attached to the noun:

• Luma ang baterya = The battery is old.

So compare:

• lumang baterya = an old battery
• Luma ang baterya = The battery is old.

They are related, but they are not the same kind of expression.

• Luma ang baterya = a full sentence: The battery is old
• Lumang baterya = a noun phrase: old battery

In lumang baterya, the adjective directly modifies the noun, so it uses the linker -ng.

So:

• May lumang baterya ako. = I have an old battery.
• Luma ang baterya ko. = My battery is old.