I've used Andy's Power Bus on Giant Scale and Jets, including one on my yet to be flown KingCat.....never any problems....solved a few long lead problems on giant scale gassers with electronic ignitions.....use on jets is less well defined, but still amplifies and isolates signals on long leads and keeps most of the servo current out of the RX bus.....Andy states that the unit, like regulators, fails in a neutral pass-thru mode rather than an open circuit, so should be safe in the rare event of a failure, and MTBF is extremely high.......

Re: 4-cell Nicad/NiMH packs and Digi Servos

Interesting article by Tom Wilkinson in latest RCJI, reviewing the West Battery Checker......he found that even at idle(no load applied to the servo) that (4)-8411s suck significant juice, and produced low voltage spikes of 4.24V with a 4 cell 1500 maH pack....dangerously low at idle.....remedied the problem with (2) 4-cell 1500 packs in parallel......then low voltage spike only down to 4.8V, with sustained at 5.0V.....IMO, use of a SINGLE 4.8V Nicad/NiMH pack to power several digi servos should be limited to large, preferably 3000maH or larger packs, with 18 ga leads, and never a single AA pack in the 1500-1700maH range with 22 ga leads, even if your flights are short and you re-charge after every flight.....

Andre:

Good point about failure modes of 18650 Lith-Ion Can cells.....vendors never qualify their "Redundancy" spin with "Even if you have 200 cells in a S/P pack, if one dies dead-shorted, you are done"....... that said, in over 35 years of using NiCads, 10 years of using both re-chargeable and non-rechargeale Liths in cameras and ham radio stuff, and 1 year using Liths in Jets, I have never personally had a dead-short, single-cell meltdown that took out the remainder of the pack.....only ones I have seen in other guy's packs were in NiCads, related to bad wiring of the cells or a serious overcharge of a Nicad(too hot to touch after the overcharge) before the days of peak detecting chargers with cell temp sensors....

Tom