Learn Hardcore Indonesian: Biar saya mengganti baterai remot sekarang.

Yes. Biar saya… is a natural, courteous offer to help. To soften it, add saja: Biar saya saja…. In very formal or hierarchical contexts, you can use Izinkan saya… or Boleh saya…?

What is the difference between biar and biarkan?

Biar before a subject (e.g., Biar saya…) is an offer or suggestion.
Biarkan is a verb meaning let/allow and can sound stronger or more commanding. Biarkan saya mengganti… can feel like insisting on permission; Biar saya… is friendlier as an offer.

Can I use aku or gue instead of saya?

Yes, but choose based on formality.

saya: polite/neutral, safe with strangers or elders.
aku: informal, with friends or peers.
gue/gua: very informal Jakarta slang. Examples: Biar aku mengganti…, Biar gue ganti…

Do I need the prefix in mengganti, or can I just say ganti?

Both are fine:

mengganti is standard and explicitly transitive.
ganti is very common in everyday speech: Biar saya ganti baterai remot sekarang.

Why is it spelled mengganti and not menganti?

The base is ganti. With the meN- prefix, before g it becomes meng-, and the initial g stays: meng + ganti → mengganti. So it must be mengganti, not menganti.

When should I use menggantikan instead of mengganti?

mengganti = replace something by putting a new one in place: mengganti baterai.
menggantikan = take someone’s or something’s place or role: Dia menggantikan ketua lama. For batteries, use mengganti baterai, not menggantikan baterai. You can say Baterai baru menggantikan yang lama (the new battery takes the place of the old one).

Is menukar a good synonym here?

Sometimes. Menukar means to exchange/swap and usually takes dengan:

Natural: menukar baterai lama dengan yang baru.
Less natural: menukar baterai remot (sounds like swapping it for something, not simply replacing it).

Is baterai the correct word? What about batere or batre?

baterai is the standard Indonesian spelling. batere and batre are common colloquial variants in speech. In Malaysian Malay it’s bateri. All will be understood, but write baterai in standard Indonesian.

Should I write remot or remote? Are there other ways to say remote control?

Both remot and remote are used; remot is very common in everyday Indonesian. You’ll also hear remote TV, remot AC, and more formal pengendali jarak jauh. remot alone is perfectly fine in this sentence.

Is baterai remot the normal way to say the remote’s battery? What about -nya or punya?

Yes, baterai remot is the usual noun–noun pattern meaning the remote’s battery. To make it definite or specific, add -nya: baterai remotnya = the battery of the (particular) remote. You can also specify the device: baterai remote TV. Avoid punya for inanimate possession here; baterai remot is the natural phrasing.

Where can I put sekarang? Is there a difference?

Common placements:

End: …baterai remot sekarang.
Beginning: Sekarang, biar saya mengganti… Meaning is the same. sekarang juga adds urgency: right now.

How can I emphasize that I’m the one who will do it?

Insert yang: Biar saya yang mengganti baterai remot sekarang. This stresses that it’s specifically you who will do it.

How do I express plural batteries?

Indonesian doesn’t require a plural marker. Context usually suffices. If needed:

dua baterai (two batteries)
baterai-baterai (formal/written plural, less common in speech)

Would it be natural to add with a new one?

Yes: Biar saya mengganti baterai remot sekarang dengan yang baru. You can also say …dengan baterai yang baru.

Any quick pronunciation tips?

biar: two syllables, bi-ar.
saya: sah-yah.
mengganti: mêng-gan-ti; the first e is a schwa.
baterai: ba-te-rai; the ai is like English eye.
remot: reh-mot; final t is unreleased.