I have a drone, so I bought 2 x 2.4/5.8ghz range extenders made for this purpose. They can also be used for a network router i suppose. They both came with a wall transformer that is 12v / 1.5 A. The range extenders are rated at 4w each so a total of 8 w. I tried this once before with a Sunhaus 2.4ghz range extender about 2 years ago. The battery to power all of this I used a DC12980 9800mah battery. I have not used the battery for probably 2 years. Occasionally I would turn the switch on the battery to see if the indicator light would come on. So for this project I tested the battery it was a little over 6 v, I charged with the charger that came with the battery till the indicator light on the charger went from red to green about 3 hours. I checked the voltage with a DVM and it was a little over 12v. so I connected everything up, my controller to the range extenders , and the battery to power the range extenders. They only stayed powered for a few moments and when I checked the battery it was 6v. So from my calculations if each module was using 1500ma / 3000 total a 9800mah hour battery should last at least 3 + hours. Is the battery bad . does the battery need some kind of charging discharging . I have a HTRC C240 DUO, not sure if this will help and the battery is smart so..... i had a nice photo to post , apparently i have not made enough posts yet.

the cells have aged it is no longer a usable pack. they are less than $50 from my quick search buy a new one
you can try a Higher amp charge on that battery.you might get a few extra minutes of voltage from it ..might