You manual should explain in "user" terms what's needed in some general way. Robert's response is limited because the details you provided are limited. The older the laptop the more likely you need the battery present. BUT, understand the laptop was intended to have battery present as well as a shock barrier to power as minor as it is, but its a plus. IMHO, its better to have the battery present regardless, even a weak one. At the same time battery or not, its not in the best interests to use the laptop as brought, it just is but if applicable you can use the non-battery laptop setup for several uses.
Can a laptop computer be operated with a power cord, --but WITHOUT a battery actually installed within the computer?