I just bought a Turbo Vado 5.0 SL and have a question I don't see anywhere, so I thought I would jump in here. Can you use an extension cord (12/3 rated) with the charger? The Specialized user manual says not to but I don't see why if the extension cord amperage capacity is high. Specialized support is non existent. One of the sales people at my dealer says it's OK but I want to be sure. Any opinion?
The Specialized site lists the SL charger at 48V, but does not note the charging current. So, some assumptions;
1. With a 4A charger like the regular Vado 5, the theoretical input current to the charger would be (48V * 4A)/120V = 1.6A.
2. With a lighter weight 2A charger, the theoretical input current would be
double half the 4A charger input or
3.2A 0.8A (sorry for the confusion).
3. Charger efficiency isn't published, but making a guesstimate based on the case temp of my Vado's 4A charger, I'd go with maybe 80% efficiency.
So, the max input current to the charger might be (
3.2A 1.6A )/0.80 = 2A.
A 12AWG extension cord can handle up to 15A, with a max length of ~50 feet, though there would be a voltage drop at this current that could damage a charger that incorporates management circuitry. Note that household wiring is a minimum of 14AWG with a Code required 15A circuit breaker that is limited by Code to a max 12A load. 12A will cause less of a voltage drop. Even this current is
300 600% of the highest capacity charger's estimated input current.
I wouldn't think this would cause any issues. Smaller AWG cords could create problems. This may be why the manual takes the safe approach and prohibits them. YRMV depending on the quality of the extension cord (damaged connectors, etc), cord length, and any other loads you put on the cord or the circuit supplying the cord.
Edit - my apologies for the maths confusion.