I've had two echo charger failures, one soft and one hard. The soft one was a blown fuse, with no apparent reason; engine battery gradually drained. Hard failure was a blown diode inside - I mean, literally exploded.
I had a Pathmaker combiner for many years, but the remote control which I relied upon failed, as as a potted assembly was not repairable. I had decided at that point to go to house plus start without splitting the house, and using the echo charger.
Maybe next time I need to address this I'll use a combiner.