I've personally found that using an underrated charger works absolutely fine... With some caveats. Trying to use and charge at the same time is a no no. Charging with it turned off works great, might be a little slower than the original, but not a crazy difference most of the time. You might find that using it turned on with a full battery makes the battery actually drain, as the laptop requires more juice than the charger can output. Keep an eye on the charger, watch for heat.
Price has gone up. Saved myself £9.99 8)
Excellent price for what it is and cable!. Thanks OP. Heat!
Nice. I was looking for something to need @Swan_Ronson 😬