I live with 4 roommates and one of them charges bird scooters for money. How do I account for the cost?

ask thenn to pay nnore for the electric bill

Easy. Go back to your bills before he started charging the scooters. Compare then with what the bills are now after he started charging. The added difference is due to his scooter charging. Charge him that difference for compensation.

OR you could make him pay that additional amount towards the monthly electric bill.

If he refuses to pay. Disallow him to charge any more scooters in your place. Or if your rental agreement specifies it, you might also kick him out of the house.

You could find the charging rate in KWh of the scooter chargers. I don't know how many scooters he is charging but the increased cost is probably very small. I charge my electric car and drive it about 700 miles per month and the cost is about $15 per month. And that is a car, not a scooter. I'll bet it costs about ten cents to charge one scooter.

Calculate how much it additional cost this amounts to and charge him that much. Usually, you're worried about putting people in a tough spot in situations like this, but he's making money doing this extra activity, it's not something he needs to do like use a space heater or use a curling iron/blow dryer everyday, or understandable like watching tv (:something anyone has option to also do), so since this is a very individual endeavor that's unnecessary he should pay for it out of "his cut" (and he's the only one getting a cut anyway).

You should figure this out, then talk to him. If you talk to him in vague terms he's going to dismiss it, you have to know how much extra he adds onto the bill.

How do you figure out how much this is? Roughly you should show him bills before and after he started doing this so he can see the difference. To figure out the actual amount, you just need to find out the wattage of the charger (watts W or kilowatts kW), how long he uses the charger (hours in a month), and then look on your bill (or utility's website) to find out the rate you're being charged for electricity. This number will be in $ per kW-hours. Calculate it like this

(Watts of charger / 1000) * (number of hours he charges in a month) * (electricity charge in $ per kW-hours)

that's how much he's adding every month. If you find the wattage in kilowatts, then don't include the division by 1000, that's it.

Suck it up. Don’t micro-manage or else you will go crazy every time someone opens the fridge or uses a blow-dryer. Feel lucky, shared living is far cheaper than living alone.

it would be about 10 cents per scooter he charges in electric usage. In a high usage area you can easily charge 30 in one night (about $3 usage per night)

over 30 days per bill he would be using a max of $100 or so (90 plus some room for more scooters averaged in)

i would raise his rent by $100 to pay for the electric he is using unless he provides a hard number he charges.