Re: Voltage Drop
"On the forum they're talking about him having to fit a switching regulator instead"
The "buck" down converters are very cheap from the Far East - about £2. The standard module accepts up to 35 volts DC and you can adjust the output right down to a couple of volts. Max current about 2amps.
They also sell "buck" up converters. The one I bought had an output capacitor marked as 35v - and it exploded during initial adjustments while I was trying to get a reading on the meter. Others advertised with the same nominal max 35 volt output had a 50v capacitor - which seems more sensible.