Is key charger working?

[jac]

Hi,

Is there a way to check if the charger for the key's battery is working?

My key is working sporadically, sometimes the car will start but sometimes it won't.

I have already replaced the battery in it. When I first replaced the battery it worked without issue for a couple of months, but it's now having the same symptoms that drove me to replace the battery, which is that the car won't start at times.

Thx