[crazy hack] 20% faster charging with your single charger Model S.

[Ulmo]

Note: Going along with other members' concerns outlined previously, there would be a risk associated with the below proposal.

What about using this: Simran AC-3000 - Step Up / Down Voltage Transformer 3000 Watt - CE Cer Voltage Converter Transformers

With this:

Tesla NEMA 6-15

Input is 120 V/12 A, output is 240 V/12 A. So, you'd get double the charging rate.

120V*12A=1440V*A; 240V*12A=2880V*A. Those don't equate. If you're turning 120V into 240V, then draw 12A from the 240V, then you would be drawing 24A from the 120V if I am correct. I believe this doesn't confer any type of benefit, even dangerously. As FlasherZ pointed out, the perceived benefit of PChild's setup is because of the limitations of the onboard charger current. It's a bit like the limitations of the size of wire. Rather than increasing wire size, one can increase wire insulation (or take advantage of wire insulation that is already sufficient for higher voltage) and then just increase voltage to put more over the same amount of wire. But that requires equipment at both ends sufficient to handle that with sufficient supply and device able to make use of it. That's very narrowly construed. PChilds seems to have done almost that, however. I'm missing the piece that the UMC or HPWC isn't rated for it, and because of that, I'm probably going to put more thought into making a Direct Current charger (from solar panels, battery storage, and/or shore AC-DC inverters) than this idea. But it was interesting to me nevertheless until I found out the supply interface equipment wasn't up to the task.

 

[wk057]

If you built an EVSE with the higher voltages in mind, then I suppose it could be done safely. Worth it? To each their own. I don't think a couple of kW boost is worth the trouble. You'd also have to keep in mind that the gen1 chargers in the Model S aren't rated for 290V, so, you'd have to do VIN checking before letting anyone charge to make sure they've got gen2 chargers.

I do think that something like this could be considered for destination chargers, though, to bump from 208V to 240V. Then the 16kW destination chargers could be 20kW.

I'd rather build a ~40-50kW DC charger...

 

[pchilds]

The transformer I used to get 290 vac, was setup for boosting 208 vac for public charging. There are just too few high current 208 vac public chargers to bother carrying it around a 50 lb transformer in the car.