Monarch lightsaber lighting issue

Hello,

I am currently trying to figure out what is wrong with my Monarch lightsaber that was purchased through UltraSabers about 3 years ago. First I will say that I don't use my saber much except for at conventions and I've only used it at maybe 4 conventions so far for just pictures, no stage combat or anything like that. I do not keep my batteries in my saber I keep a set on my charger at all times and the other set is in the case they came in and I switch them back and forth from time to time, but they are never kept in my saber for more than 3 days. I have had issues with bad batteries when I first received it and with a new set of batteries from UltraSaber it was fine.

Now, my current issue that is quite a big issue to me. I put my fully charged batteries into my saber. It makes all the normal noises, saying "Obsidian." I push the button to turn it on and everything comes on for about 30 second and then the blade slowly dims out and goes out, the sound still works and the light around my button still works. I turn it off and turn it back on and the blade won't come back on. I switch the set of batteries that are in it and again the sounds and saber comes on and the saber dims out again after 30 seconds. I put the batteries on the charger after taking them out and they all say that they are fully charged.

So my question is, what is going on with my light saber and why is it doing this? I'm not happy that I have now had 2 issues with my saber in the span of 3ish years and my boyfriend isn't happy because he's the one that bought my saber for me and it's not working right. I love the looks of it I just want the saber to fully work.

Any suggestions?