Charging using extension leads

6 replies [Last post]
Joined: 07/29/2008
Points: 19

Hi all,

I am seeking to take advantage of members electrical/electronic expertise, to learn what limits should be taken into consideration when using extension leads for charging.

* What should be the maximum length of an extension lead?
* Should you use 20 or 15 amp cable?
* Should you use 20 or 15 amp plugs?

I seem to recall that Vectrix had approved the use of an 8 foot lead for charging (hardly seems worth it!)

I would guess that the higher the amperage of the cable & plug combination, this should provide the best flow of electrons allowing a longer cable length.

But is there some formula on how these variables will affect the length of extension lead that can be used?

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Joined: 07/21/2008
Points: 91
Re: Charging using extension leads

You should have no problem using an extension cord to charge a Vectrix. In the US it draws no more then 15 amps on a 120 volt service. The longer the cord, the more voltage drop there is--for a short cord, 12 gauge is overkill, for a longer cord you could go to 10 gauge. I don't understand Vectrix's stand on extenison cords. Every socket you plug into is an extension from somewhere. If you plug directly into a 15 amp wall socket, it most likely is being fed by a small 14 gauge conductor from your circuit breaker panel--that is smaller in gauge then either of the cord sizes I suggested and the wire run could be an easy 30 feet or more. If you have the choice of using a 20 amp socket, use it. In the US 20 amp sockets are fed by a minimum of 12 gauge wire and most can be identified by a different shaped hole in one side of the socket to accomadate 20 amp plugs.

Buzby's picture
Joined: 04/26/2008
Points: 318
Re: Charging using extension leads

I think you'll find the concern is related not to performance or voltage drop issues, but the more mundane one of physical safety.

The longer the cord, the greater the chance to trip over it or somehow become obstructed by a messy - plug/socket connection in an inappropriate place. Also add to this the prospect of the connection becoming separated, leaving the bike in an uncharged state when you most need it.


- Raymond

dogman's picture
Joined: 04/29/2008
Points: 830
Re: Charging using extension leads

Obviously Vectrix guys never worked a constructuon site. We'd pack nothing but 12 guage cords and think nothing of 100' of that before splitting it three ways for three saws, each on thier own 50' cord. Any more than that though, and you would have to wait for silence to pull the trigger on your saw, or you might have to go flip the breaker back on 150' away. I'm not sure how a long cord gets tripped on or unplugged easier than a short one. I have been told not to pull a lot of power through a coiled up cord though.
Anyway, if you pull about 15 amps through a 50' 16 guage extension cord for 12 hours or so, it will get warm, but that's it, it won't catch fire or anything. If it does melt down, it will be because of a bad plug, not the wire, and crappy plugs come on all guages of cords.


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Webmaster's picture
Joined: 11/16/2006
Points: 684
Re: Charging using extension leads

I know this is an old discussion. I have put together a resource page about using extension cords and power adapters to enable charging electric vehicles in the field at any power outlet.

Currently the information is US-centric, so I'd appreciate some help from those outside the U.S. to fill in some details. Also, I see things a little more cautiously than some of y'all are saying. Call me a Nervous Nelly, but I prefer being safe than sorry.


- David Herron,

Joined: 07/07/2007
Points: 1686
Re: Charging using extension leads

Vectrix's issue with extension cords was if the voltage at the charger fell below 100vac the charger would try to draw more than 15A to compensate and consequently burn out

obviously not an issue when charging from 240vac when in the rest of the world


Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah
Vectrix 60Ah Lithium Tyres Fuel Registration Insurance cycle analyst 2 x TC Charger & MC
Spent so far: $5800 + $7000 + $2040 + $1200 + $425 + $800 + $140 + $3000
Cost to do it again: $1000 + $3800 + $2040 + $1200 + $425 + $800 + $140 + $1500 (lasts longer)
Cost for a Petrol bike:$6000 + + $1440 + $7560 + $1000 + $1600 + $4000 servicing
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Joined: 03/21/2014
Points: 488
Re: Charging using extension leads

As I posted in the other related thread:

If you are running the Laird's firmware, the charging current is 1/2 the original. It is about 6A max, perhaps a bit more if we factor in some inefficiencies in the charger.

So, this means, just about any 15A-rated (or more) extension cord would have no problem handling these 6-7A of current and your charger will not work extra to maintain that current with an extension cord. I use a medium dury 15A orange cord (the garden variety sold in the US) that is about 30 feet (10m) long and it barely warms-up at the plugs, cold everywhere else. My vaccum cleaner warms-up its extension cord more during use, so I'm not worried. That is all at 110V in the US. In 240V countries, it will be even better and longer extension cords can be used.

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