No power with a brand new battery, not even ignition lights

you might have burned out the new switch

> bought this computer a couple of months ago

Then, it should be FULLY covered under WARRANTY, either from the store from where you bought it, or from ACER.

> new battery from COSTCO

It's probably 100% fine; it's your laptop that is the problem.

Exercise the WARRANTY to get the laptop repaired/replaced, at NO COST to you.

basicaly you need a new battery sorry

Was the battery checked before it was sold to you? Batteries will lose their charge over a period of time even when not hooked up. If you have a voltmeter it should read 12.8 volts on a fully charged battery.
Have you tried to boost the car with cables?
I suspect if the car was working OK 3 months ago it should start. Which leads me to suggest an undercharged battery.

try to check the battery terminal. I had the same problem 3 days ago. All I did was tighten the battery terminal. If this doesn't work. try to test the battery. Its possible that that the battery is bad already even if its still new.

Most Dell batteries have an LED indicator that allows users to see how much run time and how much overall battery life are available at the touch of a button.
To check battery charge, press the button and the number of lights that appear will tell you charge status. If all lights appear, you have a fully charged battery. Each light that appears accounts for approximately 20% charge.
To check the battery health, press and hold the status button on the battery charge gauge for at least 3 seconds. If no lights appear, the battery is in good condition and approximately more than 80 percent of its original charge capacity remains. Each light represents incremental degradation. If five lights appear, approximately less than 60 percent of the charge capacity remains, and you should consider replacing the battery
if the ac adapter will power the laptop without the battery installed its fine. if the cord is fine and your battery is fine its a mother board issue and it will most likely have to be replaced

you got a bad battery. If your old battery works fine, and the new one wont hold a charge, Take it back to the store and get another.

I have the same problem, and for now an external charger is the best solution. Also try resetting 4 times. I also got a new power supply, but problem persist. Good luck!!!
jav

take the phone and have it either reflash or the main-board replaced.

proably bad motherboard