Is it possible to convert battery powered Christmas lights to use an electrical outlet?

My grandmother had her Christmas lights installed by her yard care guy this year but afterward decided it needed something more so she made some Christmas wreaths and attached them to the exterior walls, she then decided those needed to be lit too so she bought some short LED light strings and put them inside the wreaths but those light strings are manually turned on and off and battery operated.

The problem with this is probably obvious, first you have to go outside every night at sunset (when the house lights on the timer turn on automatically) and manually switch the lights on each wreath on. Second, they're eating the batteries, each strings takes 3 AA batteries and they only run about 30 hours and a third of that time is a "low power" dim light. And finally, of course, you also have to go turn them off by hand and if you forget to do that before you go to bed you waste most of their battery on them being lit overnight.

So what I was wondering is if there is a practical way to convert them to use an outlet so that I can just connect them to same line the other exterior lights are on and let them operate on the timer with the rest of the house.

As for technical information, the only info I see on the box is that they are:

20 LED C3 lights and on a separate line it says "4.5 Volts".