Place it under your underwear or socks in a drawer. If the topmost underwear piece is white and has been stained by you with coffee on purpose, you can virtually guarantee that no one will lift it up and search underneath it.
I generally don't recommend keeping much cash at home, since there's always the possibility of losing it, getting robbed, or losing the house to a fire or other natural disaster. Even if you keep money in a vase, a robber might think it'd be a good gift for their mom/girlfriend.
There are a few places that can be fairly safely used, though.
a. it ...
Sorry but I do not recommend non-valuable things (bottles of drinks, unusable books) because someone can throw them like your mom while cleaning.
It is also a not good idea to hide it in a secret place because someone can find it. Believe me, your hidden treasure can be lost.
According to me, the best option is your locker room (school/office locker rooms ...
I would search the Internet for, "Where are likely hiding places for cash at home" and avoid using any of the answers given since someone has already found those places.
Here are the ones that are popular to avoid:
Under the mattress.
Inside the water tank on the back of the toilet or taped to the outside back.
In the freezer
The pantry - cereal box, ...
You can buy "secret stash" items. They look like various non-valuable things, cans of food, bottles of drinks, books, even light switches. If you're very handy, you might be able to make such an item. Which will work best for you depends on circumstances -- if you don't normally keep food in your room, obviously a "can of beans" isn't a good choice (or if ...
Leave the cap of the lid off and manually "push inwards"? It looks like the action needed to open the kettle is compressing the spring so take that action manually. If you can push it too far and the mechanism will become damaged, wind a screw in inhibiting the movement of the U shaped plastic so it cannot be moved so far
Reassemble the kettle and fill ...
I put my oil heater in a corner with a small fan mounted on the wall near the ceiling. The hot air rises up along the wall toward the fan, which then draws in the hot air from the ceiling and blows it down into the center of the room.
It seems pretty efficient and the air is well mixed.
I'm using one of those small floor fans you can tilt up and down, ...
(inspired by @subjectivist's and @caius-jard's answers)
increase your supply of rechargable batteries and rotate their usage.
e.g. with four batteries you can charge all 4 → use 3 → when they're done, you're left with 1 charged and 3 uncharged → charge 2 → 3 charged ready for use + 1 uncharged waiting for the next chance to charge → when the batteries are ...
The safe bet, although a bit more expensive, is to use 6 batteries:
use 3, recharge 2, 1 left empty;
use the other 3, recharge 2, 1 left empty;
recharge the 1+1 left empty batteries.
This will ensure uniform proper charging / discharging cycles for all batteries.
There might me a slight concern that some batteries will stay dis-charged for some time, ...