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Dan W

@kudra the size of a battery able to generate enough current to charge an EV would be the size of a semi trailer.

Fast charging is only possible on mains power due to the amount of current required.

There is no shame in getting your vehicle towed when you forget to have range anxiety.

Most people who run out of petrol or diesel in their ICE vehicles get their vehicles towed when they run out of fuel, or when they get a flat tyre.

20 March at 7:18 | Wall-to-wall | Open on aus.social
8 comments
Kudra :maybe_verified:

@Salvo sure, I recognise that's probably the most sensible option currently (actually better would be a rope tow because that actually will charge your battery as well, haha!), but I would have thought there would be tech to essentially allow an EV sized battery to transfer energy to an EV via DC: I'm not an electrician but I do understand a bit about off grid power, though I am very far from a full bottle! I might ask a few electricians I know their opinions about what is possible now, or might be possible in future.

@Salvo sure, I recognise that's probably the most sensible option currently (actually better would be a rope tow because that actually will charge your battery as well, haha!), but I would have thought there would be tech to essentially allow an EV sized battery to transfer energy to an EV via DC: I'm not an electrician but I do understand a bit about off grid power, though I am very far from a full bottle! I might ask a few electricians I know their opinions about what is possible now, or might...

20 March at 7:24 | Open on aus.social
Leszek Ciesielski

@kudra @Salvo If you know someone whose EV has V2L functionality, you could call them and ask for help. But it is slow, adding 2 kW per hour would give you about 10-15 kms of extra range after 1 hour. At least it's easy to do.

20 March at 7:37 | Open on hachyderm.io
Dan W

@kudra the thing you need to remember about EVs vs Off Grid power; a typical mobile off grid setup would be between 100Ah and 500Ah at 12v (between 1.2 and 6kWh).
A fixed off grid array may have the equivalent of x24 12V LiFePO3 100Ah battery’s (about 30kWh)
Even a small EV like a Leaf or an EQA will have at least 30kWh.
A single drive Tesla is over 60 and a dual drive is over 80kWh.

The only practical way is either a (vender specific) mobile workshop battery swap or a diesel generator on a diesel truck.

@kudra the thing you need to remember about EVs vs Off Grid power; a typical mobile off grid setup would be between 100Ah and 500Ah at 12v (between 1.2 and 6kWh).
A fixed off grid array may have the equivalent of x24 12V LiFePO3 100Ah battery’s (about 30kWh)
Even a small EV like a Leaf or an EQA will have at least 30kWh.
A single drive Tesla is over 60 and a dual drive is over 80kWh.

20 March at 7:45 | Open on aus.social
Kudra :maybe_verified:
Dan W

@kudra
Interesting.
3.35kWh per unit.

Each unit can put out 20kW.

If they can sustain that output, an array of four if them may be able to charge a Dual-Drive Tesla within an hour.
Heat buildup from that sort of current would be an issue…

sparkcharge.io/pages/roadie-po

20 March at 8:02 | Open on aus.social
Kudra :maybe_verified:

@Salvo definitely. I'd hope the people building these have taken that into consideration! - you could be smart charging the modules based on how recently they had been discharged, then loading them into the rescue vehicle as needed... I'd say the majority of uses are going to be when a planned charge cannot happen due to faulty charger or random incompatibility (had happened to me a couple times but I was able to get to the nearest charger, but in some areas that may be a problem, particularly rural Australia!) and you won't need to be charging the vehicle to 100 percent, just to the nearest static DC charger.

@Salvo definitely. I'd hope the people building these have taken that into consideration! - you could be smart charging the modules based on how recently they had been discharged, then loading them into the rescue vehicle as needed... I'd say the majority of uses are going to be when a planned charge cannot happen due to faulty charger or random incompatibility (had happened to me a couple times but I was able to get to the nearest charger, but in some areas that may be a problem, particularly rural...

20 March at 8:10 | Open on aus.social
Dan W

@kudra looking at the size of the units, and looking how much charge they claim to hold, I gave a feeling that they are fudging some of their numbers or my maths are incorrect.

If 4 units is enough to charge a dual drive, you wouldn’t be able to carry them around.

20 March at 8:17 | Open on aus.social
Kudra :maybe_verified: replied to Dan

@Salvo enough to get them to the nearest charger only perhaps, not fully charged?

20 March at 9:26 | Open on aus.social
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