Replacing laptop batteries
We can’t recommend a particular place to get replacement laptop batteries as they are specific to the laptop (or range of laptops), so there is no one good and easy one-stop-shop.
To buy a replacement battery for a laptop, you need to find the model number for the battery. This is usually listed on the battery itself. You can search the internet for this model number to find places to buy it. Sometimes the make of the laptop will sell it. Definitely try marktplaats, but you may find that it is only available on eBay, Ali baba, or Amazon (ugh!). Sometimes one battery will work for a several different laptops. In this case, you need to check the model number of your laptop is listed in the description of the battery (probably you find a battery by searching for its model number). It is also possible to search for “replacement battery” and the model number of your laptop.
NL seems to have a lot of random specialty stores (warehouses that only sell all of the garden lights or something) so it is possible there is some online store that only deals with laptop batteries.
Buying a second-hand battery is possible but perhaps not ideal. You do not know whether the battery is in good condition and (especially old) lithium batteries can burst into flames under (admitted rare) circumstances.