GPowers
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plus on on the square watermelons.
A peek at the Leaf's Charger
- Thread starter Ingineer
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Deleted member 3147
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If you drop it far enough, the round one won't roll away either! :mrgreen:mwalsh said:DarkStar said:
Plus they don't roll away from you when you loose your grip on them!
rmay635703
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KeiJidosha said:
Actually you might not need to change anything (besides a thermostat or two) about the wiring harness to get up to 6.6k. Read on if you want to know why...
Anyway despite the above, This still Sounds to me like a classic case of penny wise but pound foolish, to have the car 6.6k ready by ac house wiring standards would have cost maybe $10 in electric wires (likely a lot lot less in reality since really only 4 of the wires needed to be a slight bit beefier) but all is not lost...
Generally for chassis wiring 10 guage would have gotten you the 33amps continous needed to run 6.6kw albeat with a bit of efficiency loss so long as ambient temperature is below 135 degrees and the charger can handle a bit of voltage drop. Me, if I were doing a rig of this type I would have used much beefier wires than those considered necessary because they are more efficient and more expandable in the future.
That said
12 guage wire is officially rated at 15amps continous duty by most but not for any official failure reason, 10amp or 15amp ratings associated with 12guage wire have to do with voltage drops over 50' and 100' and not any actual failure risk.
I would recommend reading this.
http://www.stu-offroad.com/electrical/elec1/wire-1.htm" onclick="window.open(this.href);return false;
There are also others on this subject with a simple google search of 12 guage amperage rating
Generally 12 guage wire can easily handle 23amps continous, this means a little south of 5kw with the existing system is just fine and dandy, and the truth is it can conservatively handle loads up to 41amps depending on temp and duration and of coarse the coating on the wires. It is worth noting that alternators on many cars rated at a little more than 60amps many times only have 12 guage wiring, this is because efficiency is not a concern and the duration at 60amps should not be continous, though it may have to output that rate for hours at a time. The odd part is I have seen a couple hundred amps forced through 12 guage without it blowing up, the risk is fire going way past its rating.
The main issues with this will be interconnects and plugs which are always failure points, the wire itself will likely not fail (even if you were to force enough juice through to burn off the coating).
The cooling system is a non-issue, if the 6.6kw system is efficient and the emphasis stays on efficiency you can make a 6.6kw system that likely dissappates no more heat than the 3.3kw and even if it does make more heat it still doesn't matter because a thermostat could be setup to protect the system such that it will run full blast until its temp raises to certain point then it would slowly derate to prevent overheating.
The same concept would be needed on the wiring, a temperature module near the "J" connector (which should by its own standard require at least 50amp connectors right?) and inside the car near any plug in connectors would be needed.
Because continous is a good long time, I would estimate the wires would not notice 4 hours at a spat and if they did reach max temperature (whatever that is) 3.5 hours in, what would you care if the charger had to derate to 4.5kw?
I would strongly recommend nissan and folks here (who have access to the wiring harnesses) do some failure testing monitoring the temperature of the chassis harness while in a car (to simulate the stuffy environment) to see how hot the harness gets at the 33 or so amps that would be needed for 6.6kw with wire losses and whether or not it fails in any way. Remember that there are many wires rated at 200c or more (sometimes ones that aren't are still made of materials good to that level of abuse) so it is well worth long term testing to see if the wires fail or if there are plug in connectors that would need replacement (much simpler than a whole harness to beef up a connector)
Any takers? I am an engineer and I disagree that a wire guage automatically dissallows a certain use, whether it is safe or not depends on monitoring and the material composition, chassis wiring has much different specs than household wires and despite what some may say here, auto wires should be good up to at least 240 deg F without issues or somebody screwed up royally.
For example, my father has a 6 year old cheap 48v 25amp chinese battery charger in his EV, it has 18 guage (or smaller) wire through out and many very underrated parts, it has been used most every day for years and still works fine (though the fan is getting noisy) It keeps working because once it hits its temperature limit it derates, oddly though it usually doesn't hit that point and has been abused for years with improper ventalation. Internally it does have a wicked voltage drop and is not that efficient but it was cheap.
So please, don't give up hope, I think this problem is being made more complex than it really is and if Nissan is reading this
PLEASE SPEND THE $0.50 and use bigger wires in your harnesses! Don't skimp on a 30k car! Components should be overrated not just meet spec, although I guess you can say you exceeded the chassis requirements but still, why not have the extra efficiency and piece of mind.
Any takers?
I am in the group that maybe we can have some external charger that uses the QC port for either 6.6 or greater with home wiring even if you dont get the max charge capacity and have to run 440V to your home. Couldnt cost much more than the standard L2 setup since most are going to do this any way and you can bring charge time down to 1-2 hrs.
Ingineer
Well-known member
Nissan already went on public record and stated there will be zero chance of upgrading existing LEAFs to a larger capacity charger if/when they offer it. I personally heard it when the Chief Vehicle Engineer and the rest of the Nissan team was in town a few weeks ago.
-Phil
-Phil
Caracalover
Well-known member
And a gym membership would cost you how much? Might just be a blessing, count them when you have time - like while waiting for a L1 charge. :lol:TimeHorse said:
I live on L1, and for me it isn't tough. Seriously sorry to hear about your situation, hope it doesn't last long.
DarkStar
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I look forward to your "modification" to allow the replacement of the existing charger with an "upgraded" one.Ingineer said:
rmay635703
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Ingineer said:
Then perhaps a 3rd party should load test the wiring harness over a period of months in a vehicle environment and check to see if there are true legal issues. Far as i know 12guage has always allowed at least 20amps in "home" wiring situations and that is only due to voltage drop and because of non-conforming materials potentially being in the mix. Chassis has always been around 41amps though in auto use 60amps intermittent is permitted. (or at least was) Since the harness is not HOME wiring the chassis codes apply, a 3rd party could offer an upgrade with minimal cost, as i said a few thermostats, a new improved charger, voila.
The leaf wiring is homo-genious, the coating can be looked up and its properties (max temp, conduction, lifespan at a given temperature) are all known. Knowing these variables would allow us to know how many amps for how long the leaf harness could operate safely. The current you can send over a 4 hour period is significantly different than continuous.
And as alluded to elsewhere, even at the home wiring limit of 20 amps a higher voltage capable charger could push out 6.6kw without changing or worrying about anything.
Cheers
Ryan
Volusiano
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I would rather see a third party 10KW charger to be put in the front under the hood. Then we won't need to worry about whether the existing wiring harness running to the back of the car is beefy enough or not, because there'd be a different beefy enough (and short enough) wiring harness going from the J1772 port to this new 10KW charger. Then the output of this charger can simply tap on to the CHADdeMO port wiring to deliver the charge to the battery DC style. So any wiring harness coming in or going out of this third party charger will be short and minimal.
Herm
Well-known member
Volusiano said:
+1000
Get busy Phil!
I guarantee Nissan designed that wire harness just for the 3.3kw charger and nothing more.. copper is too expensive to waste.
EVDRIVER
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TimeHorse said:Herm said:
+$1,500 if you can put a 20kW charger in there like the just-announced upgrade for the Tesla Model S whose base model is also 10kW but my EVSE, tee hee hee, can indeed do 20kW.
That won't get you a 4kw charger. A charger upgrade for the LEAF is very expensive and labor intensive thanks to the thin wire Nissan used. This has been covered extensively.
TimeHorse
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EVDRIVER said:TimeHorse said:Volusiano said:
+$1,500 if you can put a 20kW charger in there like the just-announced upgrade for the Tesla Model S whose base model is also 10kW but my EVSE, tee hee hee, can indeed do 20kW.
That won't get you a 4kw charger. A charger upgrade for the LEAF is very expensive and labor intensive thanks to the thin wire Nissan used. This has been covered extensively.
Context: I was talking about Volusiano's idea of using the existing CHAdeMO harness to run the current to the battery DC from a second rectifier in the bonnet of the cab connected to the J1772 plug. Whatever price this would cost, I'd pay $1500 more since if Tesla can replace a 10kW charger with a 20kW charger for that price and we're all using whatever technique to get the 10kW in, I say I'd pay the add-on and go for 20kW. If it does have to be rewired for 10kW because replacing the existing charger is the only practical solution, then a massive rewiring job would be required for the 10kW upgrade or the 20kW upgrade. Personally, I doubt the holes and bends that the current wiring has to go through would be wide enough for a wire gauge sufficient for 80A sustained at 240VAC but we won't know until we try (or review the detailed car specs).
Volusiano
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To be honest, it wasn't even my idea to begin with. I think it might have been Phil's (Ingineer) idea a while back when he was tossing around the idea of installing a third party 10KW charger in the front under the hood.TimeHorse said:
The beauty of this idea is that:
1) you don't have to rely on the flimsy wiring from the J1772 port to the back of the existing 3.3kw charger if the replacement charger is placed up front. You can just tap on the J1772 port directly with a new harness beefy enough to handle 10KW into the new 3rd party charger. This harness doesn't have to cost a lot of money because it should be short enough.
2) And if the output of this new 3rd party charger can tap on the CHAdeMO wiring already in place up front going to the battery, then no new long beefy harness is necessary to connect to the battery pack either.
3) You can just drop the 3rd party charger in the front under the hood, tap into the J1772 and CHAdeMO, and voila, you have even a better upgrade solution at 10kw than Nissan's 6.6kw solution.
FairwoodRed
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EVDRIVER said:
Did this extensive prior coverage talk about Current Ways chargers? And did it mention how expensive is expensive?
I haven't seen answers to either question and I also couldn't find any answers by searching.
