Has anyone had a problem using a Marcum battery with a Vexilar Flasher. I have an FLX 28 and am trying 2 different lithium marcum batteries. Both batteries are fully charged based on volt meter but won’t power up the flashe. Flasher works fine with both the original lead acid vexilar battery and an amped outdoors lithium, just won’t work with the Marcus’s. Any ideas?