Sounds like a battery issue to me too, certainly the first thing to check. Then check the ABS fuse is good & not corroded (Owner's Manual pages 6-30/1)
The ABS operation is explained in the OM, pages 3-5 & 3-28/9 for my 2014, may differ for a 2012. The iregular firing of the ABS light does lead one to suspect a wheel sensor fault as the next possibility to consider, so a check of the wiring to each sensor is needed. Then remove each sensor to check it's face is clean & undamaged. Sometimes the sensors & wiring get damaged/pulled/pinched at the tyre depot.
Occasionally we hear of tyre diameter changes confusing the system &, rarely, we find previous owners have fitted an ABS cut-out switch to disable the system during extended off-road riding, which could create issues if wired poorly. Failing this, it's probably a job for the local dealer to check out the system as there could be issues with the ABS pump - there are various threads on here regarding changing the brake fluid & inducing the ABS pump which may help, so search is your friend. Presumably the brakes work OK in every other sense & don't need to be pumped each morning, due to air in the system?
Good luck finding the gremlin. Keep us posted ............................ KEN