# Will Leaf 6.6kW onboard limit a diy charger?



## Dougnutz (Aug 22, 2011)

I think you misunderstand the difference between and evse and a charger. The Leaf has the charger onboard, the charging rate is the max of the charger or the evse. Which ever is lower. So for example the cord that comes with the leaf is an evse designed for a standard 110 wall outlet. It supplies a max of around 1.5kw (I forget the exact amount). So using this the leaf is limited by the evse. If you have a home EVSE capable of say 7kw then your onboard charger is the limiting factor. 

The Diy charger kit is designed for charging the battery directly. It is not an EVSE. This is for conversion projects and such. It is not intended to supply the Leaf's charger. 

The confusing part is that there are DC fast chargers. These are external chargers that supply power directly to the Leaf's battery through a special port. These chargers bypass the onboard charger. Which is why they can charge at a very high rate. These still use a special protocol so that they are controlled by the onboard electronics of the Leaf. The DIY kit will not interface with this port.

With all that said ( and I may have some details wrong) I think the Guys working on the DIY kit have been looking at interfacing with the fast charge port. This could be interesting as it would theoretically allow up to 10kw charging. I don't know how much progress has been made there though. And doesn't really seem worth it on a 2013 Leaf with a 6.6 kwhr charger. Since the fast charge connector alone is quite expensive. On a Leaf with a 3.3 Kw charger it might be worth it.


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## adeyo (Jun 6, 2012)

Dougnutz said:


> 1... The Leaf has the charger onboard, the charging rate is the max of the charger or the evse. Which ever is lower....
> 
> 2...The Diy charger kit is designed for charging the battery directly....
> ... These are external chargers that supply power directly to the Leaf's battery through a special port. These chargers bypass the onboard charger....
> ...





1. (from quote above)... That's what I was afraid of... The limiting factor of the onboard leaf 

2. I believe I have heard the leafs direct battery hookup can be accessed via a panel near the front passenger seat. Can anyone confirm? Thus, it might be possible to bypass the onboard charger 

3. I have been following (a little  valruns diy kit and wondered how it was that he could fast charge a leaf... He shared with me they are planning a CHAdeMO version, but I didn't know how (or if) it would override/bypass the leafs onboard system. 

Thanks Doug! That was a really helpful post. Clarified a lot. A quick charge connection on a leaf would be awesome for one of these portable chargers! I have purchased someone's incomplete s10 EV project (a kit from ev America) and I was hoping to buy one charger and do double duty with a Nissan leaf. (in some way, I'd possible. Sounds like the quick-charge connection option - if it comes to fruition could be perfect for my scenario.


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## frodus (Apr 12, 2008)

Victor Tikhonov (Metric Mind) has 2 Brusa chargers in the back of his leaf. He can charge most of the way in ~100 minutes.
http://www.metricmind.com/leaf/main.htm


Here's a thread about others doing the same:
http://www.mynissanleaf.com/viewtopic.php?f=37&t=12323


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## adeyo (Jun 6, 2012)

frodus said:


> Victor Tikhonov (Metric Mind) has 2 Brusa chargers in the back of his leaf. He can charge most of the way in ~100 minutes.
> http://www.metricmind.com/leaf/main.htm


Thank you for the links! After reading through his post, It seems like one could go to the passenger seat, directly near the primary battery Inlet and splice into the feed (as Victor has done) only to add a bypass twist lock type of connection. Connect valeruns 12 kW 70amp charger temporarily via twist lock (or semi permanently by feeding to the back cargo area). whenever a quick charge is desired, charge using valeruns charger and built in bms. When the charge is over and the car turns on, the dash should still read display the charge information correctly. 

Is this possible?? 

Then, in my case, remove the charger for use with my future home built s10. 

Feedback? Risks?


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## valerun (Nov 12, 2010)

We'd be interested in partially sponsoring such a test...


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## onegreenev (May 18, 2012)

I have a 2011 Leaf. Be happy to test it. I'd love fast charging for the Leaf.


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## valerun (Nov 12, 2010)

onegreenev said:


> I have a 2011 Leaf. Be happy to test it. I'd love fast charging for the Leaf.


you are in SAC, right? could work.


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## adeyo (Jun 6, 2012)

I look forward to how this one turns out! This would give new life to all the 2011-2012 leaf owners who currently have no hope of a quick charge.


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## onegreenev (May 18, 2012)

I'd love to be able to tap into my Chademo port on my Leaf. I'd rather not change that port out but would rather tap into it.


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## adeyo (Jun 6, 2012)

onegreenev said:


> I'd love to be able to tap into my Chademo port on my Leaf. I'd rather not change that port out but would rather tap into it.


exactly. that would be convenient. 

I have access to a NEMA 14-50R outlet at work. I believe it's 3 phase. Would it be AC or DC? I'm assuming its AC. Can anyone tell me if it would be at all possible to somehow use the Chademo port with something that carries this type of amperage? (if i want charge at a decent rate i must somehow bypass the small 3kw onboard charger). 

Or is it impossible to use the Chademo (DC current, correct?) w/ AC current coming in??? 

What should i do to bypass my week charger or at least maximize my ability to charge rapidly??


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## onegreenev (May 18, 2012)

Chademo is DC only. You can not feed AC into the Chademo plug. It is directly into the battery and not into a charger. The external DC is controlled outside the vehicle.


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## JasonA (Aug 8, 2013)

While Victor taped into the battery in the back, the Leaf would not like power flowing just with a separate charger alone in the back. He runs his Brusa's all together with the main Leaf charger as well because he needs the pump and cooling system working.

Activating a 3rd party charger and pumping current into the sensors and shunts without the stock Nicheon unit or Leaf activate might cause damage.

I should know, I'm the first one who did the Brusa on the Leaf forums and integrated the CAN system with help of another Leafer.

If you're considering putting a larger charger in the back (especially non-isolated).. you will have to engage the Leaf before kicking the "big-ass charger" or BAC as we call em.

The Leaf has a great deal of leakage detection and HV protection and will trip or cut off the HV or brick if there's an issue.

Be careful!!
Jason


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## JasonA (Aug 8, 2013)

onegreenev said:


> Chademo is DC only. You can not feed AC into the Chademo plug. It is directly into the battery and not into a charger. The external DC is controlled outside the vehicle.


In a certain sense.. It's still controlled and isolated by the Leaf's contactors... Never live and never hot so it's not "direct into the battery"

Also.. the onboard charger is what controls the CHAdeMO power through the CAN bus..

The BIG POWER unit is just a DC power supply or a BIG DC EVSE..

The Leaf is still controlling and calling the shots for power..


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## adeyo (Jun 6, 2012)

JasonA said:


> Also.. the onboard charger is what controls the CHAdeMO power through the CAN bus..
> 
> The Leaf is still controlling and calling the shots for power..


so, what if i have approx. 480 volts coming in from solar panels -DC...(i.e. i bypass my inverter and go straight from DC into my Chademo port). 

If the leaf controls the DC charge too, wouldn't there be a way for me to make this possible? (provided i have sun from my 10kw solar array)????

thanks for your previous response, btw


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## JasonA (Aug 8, 2013)

The only problem I see with solar (and I have it also) is it can be flaky unless you're in Arizona and you have pure sun with no issue. Even here in Cali we have tons of clouds going by because its humid and wacky right now.

You'd need a good way to keep that power regulated.. CV & CC if nec. When you watch a CHAdeMO charger... then you know the amps and volts just HAMMER down hard!! 

As the amps stay in the 100's.. the voltage comes up..

if clouds or ANYTHING went over your array, the Leaf will probably not like that and disconnect because you'd drop below the pack voltage.


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## valerun (Nov 12, 2010)

JasonA said:


> The only problem I see with solar (and I have it also) is it can be flaky unless you're in Arizona and you have pure sun with no issue. Even here in Cali we have tons of clouds going by because its humid and wacky right now.
> 
> You'd need a good way to keep that power regulated.. CV & CC if nec. When you watch a CHAdeMO charger... then you know the amps and volts just HAMMER down hard!!
> 
> ...


+1. likely won't work. the car expects the charger to follow its directions very very tightly. there are certain tolerances on how much discrepancy is allowed for how long, etc. To make solar work with CHAdeMO, you will need either grid tie or a separate battery buffer unit


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## valerun (Nov 12, 2010)

JasonA said:


> While Victor taped into the battery in the back, the Leaf would not like power flowing just with a separate charger alone in the back. He runs his Brusa's all together with the main Leaf charger as well because he needs the pump and cooling system working.
> 
> Activating a 3rd party charger and pumping current into the sensors and shunts without the stock Nicheon unit or Leaf activate might cause damage.
> 
> ...


Hey Jason - are we doing the 12kW test?? ;-))


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## JasonA (Aug 8, 2013)

valerun said:


> Hey Jason - are we doing the 12kW test?? ;-))


I'd like to, my only issue that I'm trying to think of currently and we spoke of this over email is cooling.

Here in SoCal, it got to 109* in the valley this weekend and no air-cooled unit would be able to handle full power charging close to the ground or stuck inside a hood without liquid cooling.

I went down to SanDiego for an EV Event and the cooler temps allowed me to keep the hood closed at every stop (but the dealership guys wanted to see the Brusa in action!).

I find that anything over 89* or so ambient and trouble starts. Worse if it'll be mounted underneath where the spare tire hole is at. Nothing but ground saturation.

Fall/Winter/Spring is no issue but an IP67 or 57 enclosed unit I think is a must.

Just my $.02

But I'm still thinking of ways and your charger!


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## valerun (Nov 12, 2010)

JasonA said:


> I'd like to, my only issue that I'm trying to think of currently and we spoke of this over email is cooling.
> 
> Here in SoCal, it got to 109* in the valley this weekend and no air-cooled unit would be able to handle full power charging close to the ground or stuck inside a hood without liquid cooling.
> 
> ...


Well, yes, at 109 ambient (43C), we have ~12C cushion before derating (at 55C). While you would not be able to run full blast at 12kW (which requires ~20C headroom), You should have no problem running at 8-9kW. Which is 2.5-3x the boost you are getting now so I'd say still pretty useful.

No?


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## metricmind (Jun 19, 2009)

Speaking of 6.6kW one, I've just added one more unit to my 6.6kW booster and got full 10 kW extra charging power - completed the project last week:
http://www.metricmind.com/leaf/main.htm
Works as good as it looks, I could not be happier with the outcome. 100 minutes 0-80% recharge time, no EVSEs of any sort.

Just wanted to share the link - it might inspire someone else to improve charging in their Leaf, albeit may be not to this OEM style extreme 

Interestingly, I'm getting emails from people who owns more than one Leaf and they want to share the booster among them to cut expense, meaning they want external variant of the booster. It can be the size of a typical luggage suitcase with 2 wheels people drag around in airports. I wonder if I should do this project too...  Personally, I don't need it - all my EVs have internal [BRUSA] chargers. I only use liquid cooled stuff: aside typical IP67 protected there is never power de-rating problem.

Victor


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## adeyo (Jun 6, 2012)

Sounds like something I'd be interested in.. An external variant that is. I would keep it in my home unless I had a 'long' road trip... I would take it then. I want the internal one, but a few variables keep me away :

1. I don't want to attempt so many modifications on my own. 

2. I would like to somehow keep the stock battery dash Guage in play somehow 

3. EDIT ** oh yeah, and would prefer no modified charging input 

Victor, if you built an external one, what are the minimal amount of modifications one could get away with to use it? Could I simply splice into the main battery terminal near the back seat and charge that way?


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## metricmind (Jun 19, 2009)

@ Adeyo:

Jason is right, the QC inlet is not connected to the battery unless QC actually takes place. So, no, mere connecting a DC source to QC inlet or tapping into this harness and expect current to flow into the battery from external charger will NOT work. I didn't verify this, but from the reverse engineered schematics I got from fellow who installed my EVision into his Leaf, couple of power contactors are inside the battery box (which make sense for OEM grade setup - external plug on the battery case is never live), and others are outside, so unless BMU senses presence of the QC charger (after handshaking over CAN), and closes these contactors, the battery is isolated from its plug. So in order to close internal contactors you need either fool BMU into thinking that QC is connected to the power inlet, or let internal charger do it for you (as I did) e.g. charge with internal charger as usual but supplement it with external power. Beauty of this method is all the comms and contactor controls are taken care for you by stock circuit. Even if you manage to close contactors (by, say feeding your own 12V into their coils), you will likely damage them - they never open or close under load - charger is enabled after closure and disabled before opening. Engaging/disengaging under load will cause them to arc and possibly weld shut if current is big enough.

To answer your question - yes the minimum mod you can get away with if you use my external booster approach is to tap into stock charger's DC output, so you can inject current into the battery from external source once stock charger starts. Then the dash gauge will register extra Ah as well. The key is doing it with internal charger - if it is dead, so is the dash and Ah counter and if you manage to charge battery without Leaf knowing
about it, next time it will try it will likely throw out error since actual capacity and voltage and what Leaf thought it is are way out of sync.

I'll try to gauge the interest in inexpensive personal portable QC - I think one can get away with like $6...7k or so. These things are on the market for quite some time, but for most individuals only worth expense if you have several EVs that can take advantage of sharing it. While $6k may sound a lot of money, it is actually cheap for the value it offers. If you feed, say, 3 EVs with it, it's just $2k per EV. Not to mention sharing with friends or neighbor or lending out...


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