Can a laptop be mailed to an APO or FPO address?
Yes. USPS's own instruction for lithium-ion batteries installed in equipment extends to APO, FPO and DPO addresses by name, the same category as mail crossing a border, and a laptop's factory battery falls well inside the limits that instruction sets.
Does a laptop need a battery hazard mark to go to an APO address?
No, as long as the mailpiece stays at or under two batteries. A single laptop is one installed battery, well inside that line, and USPS's own instruction for this category of mail states that no lithium battery markings are permitted — the correct box carries none.
Is the domestic battery rule or the international one used for APO mail?
The international one. USPS titles the relevant packaging instruction “International and APO/FPO/DPO,” naming military mail in the same rule as mail leaving the country, not in the separate domestic rule.
Will a spare battery packed alongside the laptop change anything?
It can. The APO ceiling is four cells or two batteries per mailpiece, against eight cells domestically. A laptop plus one spare battery pack still reads as two batteries either way, but a handful of loose small cells thrown in alongside it is where the lower APO number starts to matter.
Can SMKlog price the whole trip to an APO address?
No. An APO, FPO or DPO address is a USPS-only lane once it leaves a domestic ZIP, and this site's checkout compares USPS, UPS and FedEx for ordinary domestic parcels. What it can price is the stateside leg before the parcel enters military mail.