He my Sterling B2B fitted by Phil at Rhino installs nice guy and very neat install, my on boat charger is Sargent PX300 and Phil says this is fine to leave on for my lithium as charge rate is 13.6v to 14.4v output which is under the 13.8 14.6 for lithium so will not overcharge.He also said they were OK ok with Banner AGM batteries, they weren't how do I know?