Is 5029LC the same as CR2450?

Yes. 5029LC is another code for the same cell: lithium (Li-MnO2), 3 V, 24.5 × 5 mm.

Is DL2450 the same as CR2450?

Yes. DL2450 is another code for the same cell: lithium (Li-MnO2), 3 V, 24.5 × 5 mm.

Same 24.5 mm diameter, but 1.2 mm tall instead of 5 mm. Only if the holder fits; thinner cells can lose contact.

Same 24.5 mm diameter, but 3 mm tall instead of 5 mm. Only if the holder fits; thinner cells can lose contact.

No. Rechargeable Li-ion: 3.6-4.2 V and far less capacity; only for devices built for it.

CR2450 is a 3 V lithium cell with a typical capacity of 610–620 mAh.

CR2450 is the same cell as 5029LC, DL2450 and ECR2450, so any of those codes will fit; no other cell here is 24.5 × 5 mm at 3 V.

CR2450 at actual relative size: 24.5 mm across, 5 mm thick. The dashed circle is a US quarter, 24.26 mm across (US Mint coin specifications).

The same cell under another code. Any of these fits, whatever the brand.

Same diameter, different thickness. These are not drop-in replacements.

Cell	Size	Verdict
CR2412	24.5 × 1.2 mm	Same 24.5 mm diameter, but 1.2 mm tall instead of 5 mm. Only if the holder fits; thinner cells can lose contact.
CR2430	24.5 × 3 mm	Same 24.5 mm diameter, but 3 mm tall instead of 5 mm. Only if the holder fits; thinner cells can lose contact.
CR2477	24.5 × 7.7 mm	Same 24.5 mm diameter, but 7.7 mm tall instead of 5 mm. Only if the holder fits; thinner cells can lose contact.

These are the same size or a similar code, and they are not equivalents.

LIR2450
Rechargeable Li-ion: 3.6-4.2 V and far less capacity; only for devices built for it.

Portable devices requiring high current (3.0 mA) and long shelf life (up to 10 years)

Is 5029LC the same as CR2450?: Yes. 5029LC is another code for the same cell: lithium (Li-MnO2), 3 V, 24.5 × 5 mm.
Is DL2450 the same as CR2450?: Yes. DL2450 is another code for the same cell: lithium (Li-MnO2), 3 V, 24.5 × 5 mm.
Will CR2412 work in place of CR2450?: Same 24.5 mm diameter, but 1.2 mm tall instead of 5 mm. Only if the holder fits; thinner cells can lose contact.
Will CR2430 work in place of CR2450?: Same 24.5 mm diameter, but 3 mm tall instead of 5 mm. Only if the holder fits; thinner cells can lose contact.
Can I use LIR2450 instead of CR2450?: No. Rechargeable Li-ion: 3.6-4.2 V and far less capacity; only for devices built for it.
What voltage is CR2450?: CR2450 is a 3 V lithium cell with a typical capacity of 610–620 mAh.
What size is CR2450?: 24.5 mm across and 5 mm thick.