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Discussion Starter · #1 ·
So the black lump Voltec that came with my new-to-me 2012 car a few months ago has died - was working fine. Next time plugged it in - not a murmur. I need to double check but I think the car is fine and able to charge from elsewhere

It's a sealed unit so no easy peaking inside for a quick (fuse?) fix.

So... to replace... There are various 2nd hand for sale, starting at £100+.

My question - am I limited to any type? I gather original Nissan Leaf and Mitsubishi PHEV were also Type 1 - if I find one of those at a sensible price, is that ok? Any disadvantage to any other make?

I'll get around to fitting a PodPoint or similar, but up until now the Granny has worked well on the overnight Economy7 tarif...
 

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Ampera aka IGOR
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AFAIK any granny charger with a type 1 plug will suit. You can buy replacement granny chargers from Screwfix. The only possible downside is that it might be stuck on 10 amp as the early Ampera granny charger had the rate of charge selectable on the unit and the later cars have it within the charging menu.
 

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FWIW I bought a more expensive one from evconnectors.com . I can set this to 6,8,10,13,16A (even on 13A plug!!) as there's a flavour which has choice of plugs to use, so you can run it at 16A on a Commando socket at campsite/cheapo-home-socket instead of more expensive wall EVSE, or can use 13A plug for domestic. 13A charging on a 13A plug is very likely to toast the socket so can't recommend that, but I do use the 6A a lot in summer as goes nicely with 4 Kw solar panels to soak up the sunshine. FWIW I reckon Ampera draws 14A at most, not an actual 16. Horses for courses!
 
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I purchased cheap Leaf 6A-16A selectable charger for 150EUR and it works fine.
OLED with temp, amperage and kWh transferred is a nice touch.
Bought this one:
 

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FWIW I bought a more expensive one from evconnectors.com . I can set this to 6,8,10,13,16A (even on 13A plug!!)
Interesting, would that work with a MY13 where the charging speed is set from the car? I can't charge the car entirely during my night rate because at 6A it has to start around 8pm for it to be charged when I leave, I can of course manually set the car to 10A which gives ample time but it more taxing on the socket, a nice medium ground of 8A would be good!
 

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Yes it will. The way it goes is the EVSE will advertise this current limit to the car. (In Type-2 this limit can be anywhere between 6 and 80A, between 0 & 6 A is never offered or used, too piddling to be worth it I guess).
The car is free to take as much, or as little, current as it wants, any time, but must never exceed whatever's on offer.

(thread diversion: car can pause if it likes, for hours if it feels like, waiting for super-cheap leccy from OVO etc, and when that's available it can suddenly come back to life & suck Amps. Big problem for VW with ID.3 that goes to sleep after 20 mins of pausing, and then never wakes up!!!)

If the offered current changes, can go up or down, car has 5 secs to react. Only matters when offering goes down, car must reduce current taken.

What may go astray is carefully-timed charging. Suppose EVSE offers 8A, that you've set for the night. Ampera may be a bit primitive for all I know, and maybe only understands 6A, and 10A-or-more, as in 2012 the GM EVSE did 6 or 10A, and wall-mounted offered 16. So what the car should do, at the start of you setting the timer carefully, is "sniff" the EVSE & charge for a few seconds to see what the actual current coming in is, could be 8.17A say, and then use this to calculate the precise time to start charging, so it finishes when you want, with car full. If it gets this stuff wrong, it might assume it has 6A only available 'coz it can't see 10+ on offer, in which case it'll start charging too early at a real 8A, and battery may get cold before you depart.

But bottom line is car can do what it likes timer-wise, it has no way at all to send info to the EVSE about when it's planning to use current. All it can do is tell EVSE that a charge is starting or has stopped. & the EVSE couldn't really care less, so long as it's got that plug in safely.
 
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I used 8A charging a week ago (was at friends house, did not want to risk tripping his fuse). So I can at least vouch that 8A works as well as 10A and 16A.
 

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The My13 car unlike the MY12 allows the user to set the limit when a granny charger is attached and this defaults to 6A, Put it on 10 and have the EVSE set to 8 and it will charge at 8 but set to 6 it charges at 6 no matter what the EVSE is on.

The trick here is to make the car think the EVSE is a chargepoint not a granny so the settings are ignored and it behaves like the MY12.
Anyone know how it detects a Granny charger? Is it simply anything over 10A offered and the car reverts to the Chargepoint setting or perhaps it reads the resistor in the plug and decides from that value if to use the Granny setting.

This may be how it works, If the cable resistance is 1 k Ω - 2.7 kΩ (13A setting) then Granny, Less then Chargepoint, after that it obeys the offered amount. So for the Granny lead that can offer more than 13A it would at a guess allow the granny to set the amount as if it was a chargepoint, for a normal granny lead then the car setting will come into play as well. :unsure:
 
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This may be how it works, If the cable resistance is 1 k Ω - 2.7 kΩ (13A setting) then Granny, Less then Chargepoint, after that it obeys the offered amount. So for the Granny lead that can offer more than 13A it would at a guess allow the granny to set the amount as if it was a chargepoint, for a normal granny lead then the car setting will come into play as well. :unsure:
No, it does not work that way. EVSE is communicating its maximum offered current through pulse width ration in its 1kHz pilot tone. Resistors are only used for signalling "vehicle connected, ready, with ventilation etc". You can configure MY13 to draw less than offered, but you cannot make it draw more.

 

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The reason you use PWM duty cycle for current signaling is that is is fail safe. A cable resistance might be altered by water ingestion, short, or bad connection. But you cannot step on the cable and make it magically alter duty cycle so car starts pulling more current than allowed. By pressing current choice button, you are just changing duty cycle on 1kHz pilot line. Of course, if you connect LEAF charger to 10A outlet and configure it to offer 16A to car, it will blow the fuse.

Regarding resistors: What happens when you press the button on the connector prior to unplugging is that it actuates the microswitch which changes the resistance. This signals the car that you are about to unplug, so car stops charging. This means there will be no current going through pins when unplugging and thus no arcing. No arcing = no erosion on contacts and no wild current/voltage spikes.

So the button is there no save wear & tear if you yank the plug it out when charging. If you yank 220V plug instead, all kind of bad things might happen.

On the top of it, the actual cable itself has baked-in resistor which signals the car how much amperage the cable can handle.

It all sounds very complicated but in reality, it is very simple system. There are multiple limits and car will charge at lowest common nominator. So if charger signals 16A but cable signals 10A car will charge at 10A. The goal is to have fail proof system which fails on safe side. Broken wire? No charge. Resistance out of whack? No charge. Cable too thin? Lower charging current so it never goes above it etc. etc.
 

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Discussion Starter · #12 ·
So back to the original question (thread creep forgiven!)...

- am I limited to any type? I gather original Nissan Leaf and Mitsubishi PHEV were also Type 1 - if I find one of those at a sensible price, is that ok? Any disadvantage to any other make?
Is the Leaf one better than the Mitsubishi? Any benefits? Or buy independent brand?

Thanks...
 

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- am I limited to any type? I gather original Nissan Leaf and Mitsubishi PHEV were also Type 1 - if I find one of those at a sensible price, is that ok? Any disadvantage to any other make?
No. You can buy any certified Type 1 charger as long as it supports your UK 220V plug. Just be aware that 16A chargers will need corresponding 16A fuse on the plug or possibility to downrate to lower current. (I do not know the leccy code in UK, you have those weird ring mains).
 

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Any type one Granny will work. For a MY12 Ampera then the car will draw whatever the Granny offers - 10A for most - unless the unit has a switch to set different values. The MY13 Cars can set 6 or 10 Amps on the charging screen .

@Elethiomel
Not so simple, The resistor sets the cable current capability (refWikipedia J1772) the car must obey this as the maximum current no matter what the chargepoint offers. With a normal untethered cable the chargepoint can read the cable and set the PWM as well. This BTW is why an extension lead should not be used as it can invalidate the safety resistor.

Granny leads (the usual 10A suspects ) probably have the 13A resistor set in them, I have not measured mine so far. This would give a mechanism for the MY13 Ampera to detect a granny lead and then use the in Car 6A or 10A option in conjunction with the EVSE offer.

If the MY13 Ampera detects the Granny (no matter how ;) ) it will use the in car setting or the EVSE setting which ever is lower. As the default is 6A that will tend to be the usage. For an 8A EVSE you need to set the car to 10A every time or find a mechanism so the car does not detect a granny is in use and so uses PWM signal only.

UK mains is 230V though normally @240, the plug is 13A and fused at that level.
 
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Yupp, I added that part in my post. There are multiple limits: EVSE rating (signaled by PWD), cable rating (signaled by resistance) and actual car itself. Lowest common denominator will be used.
 

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@Elethiomel
Not so simple, The resistor sets the cable current capability (refWikipedia J1772) the car must obey this as the maximum current no matter what the chargepoint offers. With a normal untethered cable the chargepoint can read the cable and set the PWM as well. This BTW is why an extension lead should not be used as it can invalidate the safety resistor.
Let's get this absolutely spot-on! Yes the in-cable resistor sets the current limit for the cable (tethered or untethered is no difference).
It's the EVSE, and Only the EVSE, that sees this resistance & checks it.
The Car cannot, and does not, see this at all.
What the car must obey is it's own rules of not exceeding it's own capability, plus not exceeding what the EVSE offers.
If someone has bodged an extension cable between EVSE & Car that's rated 13A (idiots), there is no way whatsoever for the car to know this. Or for the EVSE to know it. So the car can pull 32A & toast it all.

Granny leads (the usual 10A suspects ) probably have the 13A resistor set in them, I have not measured mine so far.
Yes, there will be some flavour of resistor in place on wall EVSEs, though granny EVSE might actually not have one, as the cable's never going to be changed is it, the mfr will code the software to 10A limit job done. But as the Car cannot & does not see this, who cares. Resistor is really there for portable cables to be safe, and to make it easier for EVSE mfrs to use anyone's controller module & anyones sockets & cables.

... probably have the 13A resistor set in them, I have not measured mine so far. This would give a mechanism for the MY13 Ampera to detect a granny lead and then use the in Car 6A or 10A option in conjunction with the EVSE offer.
No! There is no difference whatsoever between how the granny and a Wall EVSE look to the car. None. the ONLY difference comes when the car looks at the signal arriving on the low-voltage CP line, and it checks the mark-space ratio to see what current is allowed. I can set my Wall EVSE down to 6A (have actually done this, Ampera charges down to about 5.5A before quitting) and at this current it's identical to a portable "granny" EVSE.

If the MY13 Ampera detects the Granny (no matter how ;) ) it will use the in car setting or the EVSE setting which ever is lower. As the default is 6A that will tend to be the usage. For an 8A EVSE you need to set the car to 10A every time or find a mechanism so the car does not detect a granny is in use and so uses PWM signal only.
To get true 8A charging, yes, set the car to expect 10A. Whether it does its own timing calcs accurately for actual 8A supply is unknown to me, but I expect it to get this correct, as it's the exact same time calcs as for 14A charging on a 16A EVSE on the wall. I'm pretty sure Ampy does activate its contactors and the EVSE also does, at the start of setting a timed charge. This will be Ampy sniffing what's what & determining what current level it can charge at.

And then you cold pay cruel tricks on Ampy, and go & change the EVSE current-offering once Ampy's really gone to sleep for hours. So it might wake up at 2 a.m. expecting to do 8 hours at 6A, discovers the true current is now 8A 'coz you upped it sneakily, in which case it will start the charge at 8A, do this for 6 hours, and complete the charge at 8 a.m. instead of at 10 a.m. as previously planned. Dunno why you'd want to do this, but you could! :)
 

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Finally got the brolly out and experimented which I should have done before, I have an adjustable wall EVSE (Zappi) and a 16Amp cable - The MY13 recognizes this EVSE as a Granny when advertising 10A and uses the in car setting, by default 6A. Over the 10A advertised and it reverts to the advertised rate or 14.4A which ever is lower.
 
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