My current charger is broken, but I found another charger which kind of fits, but im suspicious if it will harm my laptops battery in the long run, what commands can I run or what can I look at to see if a new type of charger is harming a laptops battery? as this isnt usb-c or anything really official.
I wouldn’t worry about the battery. Any potential harm comes in before it gets to the battery, and there’s likely a DC-DC converter before that anyway.
The first thing to validate is the listed specs. If your laptop expects 12v (usually listed on a sticker on the device), don’t connect a 19v brick. Same for center-positive/center-negative. USB-C bypasses all of that, since it negotiates a matching spec before charging.
The second thing is how well it adheres to the specs it lists. This isn’t something that you can really test yourself. It would require a lot of specialized equipment and skills, since the answer can change in different circumstances. It might work fine for a while, but eventually deliver rich, chunky volts. This will (likely) fry the motherboard, and maybe more than that. USB-C does NOT bypass this. Some of the worst chargers on the market are USB-C.
The only realistic way to avoid the second is to get a quality charger from a trustworthy source. Many will only recommend OEM, but you also have to be careful about counterfeits on eBay or scAmazon. You can use aftermarket, but only if it’s a trustworthy brand like Anker.