Need help converting solar light to wired DC

[flapbreaker]

I purchased some solar flicker flame outdoor tiki lights which I really like. The downside to them being solar is that each light does not get equal amounts of sun in my back yard so the length of time they remain on and their brightness can vary somewhat. Also, they have a photosensor and turn on automatically however they also don't turn on all at the same time due to lighting variations. My bid idea is to try to wire them like typical low voltage yard lights but I'm missing a few bits of knowledge and am hoping someone can help. I took one of the lights apart to see if I could figure out the power requirements. There's nothing written on the circuit board regarding power however there is a rechargeable battery with the following specs 2000mAh, 3.7V, 8.1WH. I don't know if this is enough information to successfully convert these.

This is what I think I need to do but there may be alternate ways do achieve my goal:

Buy a typical outdoor 12v low voltage transformer

then use a 12v ac to dc converter module and wire all the lights to the converter.

What I'm not sure of: can one converter module run 8-10 of these lights. I see that these modules have certain max amp outputs

 

[dmxtothemax]

since the LED lights only need 3.7v, then a 12v transformer is not best suited.
A lower voltage like 6 or 5 v would be better,
Then use a resistor to trim the voltage
Or perhaps wire 3 lights in series.