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Discussion Starter · #1 ·
Hi all,

(I am new to the forum so I hope I have followed the rules and not asked a question already dealt with, thanks for your patience)

I drive a Nissan Leaf 2014 6.6kw model and was previously using a 20A Type 2 to Type 1 lead when charging at home, I decided to upgrade my charging cable from 20A to 32A, as the facilities at my flat said the charging unit was capable of delivering upto 32A. I have been keeping a track of charing times with the 20A cable and after charging with the 32A cable I see absolutely no difference in charging times.

My questions are; should I expect an improvement in my charging times?
If yes, then where could the problem most likely lie, is it with the leads, or the unit or the car?

If the answer is no I am considering sending the cable back to the company.

Thanks for any help in answering this question.

Raafox
 

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That's an interesting one.

On a 32a feed to a 6.6kw (~32amp) car, but with a 16a* cable, the cable will negotiate with the car and tell it how fast it is able to charge at. Theoretically, excluding heat loss etc etc, approximately 16amps.

Upgrading to a 32amp cable, you would mathematically expect double the speed - note in the real world you won't get double, but you should certainly get noticeably faster.

*as I understand it, cables are typically 16 or 32amp, not 20amp, though I might be wrong.

Out of interest, what charge speeds are you getting, then we can tell you whether they sound right. Does your cars dash definitely give you a 3.3 AND 6.6 time-to-charge reading?
 

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Yes, you should notice an improvement between the 16A evse and the 32A evse, with the LEAF it's not exactly twice as fast - as an example, if you previously did a full charge in 6 hours on the 16A evse then on a 32A you'd be looking at 4 hours for the same charge.

As for your problem, I'd double check that the new cable you have is actually rated at 32A, then I'd go and check the evse at your flat.

If it's a rolec unit you will probably be able to see what the amperage of the rcd/rcbo (I can never remember which is which), for a 32A unit it should be rated at 40A, any lower suggests that your unit is only capable of 16A.

If the unit is a polar or British gas or another manufacturer then you might be able to trace the supply back to the consumer unit to find the rating of the rcd/rcbo.
 

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Yes, a lead also dictates the charge rate. It has a built in resistor to modify the charge rate. (Sorry @UKTechie what you've put isn't right)

Look on the charge unit and see what it says. There should be some sort of label displaying its charge rate.
 

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Discussion Starter · #7 ·
Hi all,

thanks for the replies, I have uploaded pictures of my home charging unit, you can see its rating but if I look under the flap I think I can see a RCD? not sure, but on that it says 16A despite the box listing 32A on the outside. (I am waiting on the electrician to reconfirm the power/charging ability of the unit).

The new cable is definitely 32A, as it clearly states that on the label.

My car definitely displays both 3 and 6 kw charging times on the dashboard. There is definitely a difference when I use the standard plug into the wall charging unit compared to the 20A cable. I have tried before buying the cable to record the times taken from different battery percentages back to 80% charge. For example with my original lead, I can charge from 42% to 80% in just under 2 hours. The new lead, took the same time to go from 44% to 80%. Similar time of year, low temperatures but not freezing. Between 4-9 C.



On another point, most of the time the 3 kw is twice the time of the 6 kw but at other times its not. It can for example say 3kw 3 hours and 6kw 2.5 hours, which it started doing after about 6 months of driving. Now that goes up and down.

Lastly one other explanation I just thought of was that perhaps the original lead I bought is actually 32A and not 20A as no one seems to sell 20A leads that I can find. (p.s. I live in Norway)

Thanks again and let me know if there is anything else I may have missed off.

Raafox
 

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'Just under' 2 hours is odd for a 40% increase on a Leaf. It should either be around 2.5 hrs or 1.5hrs. Suspect you might have already been charging at 6.6kW (slowed a little due to cold? They don't usually slow at this charge rate) and somehow your lead was delivering at that current?

You'd really have to do a charge from next-to-nothing in the battery, with a stop watch, to get a real handle on the time. The charging time on the dash is a bit of an estimate.
 

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Discussion Starter · #9 ·
'Just under' 2 hours is odd for a 40% increase on a Leaf. It should either be around 2.5 hrs or 1.5hrs. Suspect you might have already been charging at 6.6kW (slowed a little due to cold? They don't usually slow at this charge rate) and somehow your lead was delivering at that current?

You'd really have to do a charge from next-to-nothing in the battery, with a stop watch, to get a real handle on the time. The charging time on the dash is a bit of an estimate.
The time i posted was timed by stopwatch, the dashboard is always wrong by a fair margin. I also am pretty sure that I am charging at 6.6kw, my question is more to do with the change in leads has not resulted in a change of charging times.

Next time I run the battery low i will time it.
 

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If what you are saying is right, then it would appear that I owe @UKTechie an apology (he's deleted his post now, but mentioned the lead could carry 30A and get hot) and you 20A lead really was carrying 30A! AFAIK this would point to some sort of fault with the lead, or cheap manufacture, that has left out the pilot signal resistor to indicate the 16A rate of the lead in the loop.
 

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[QUOTE="howartp, post: 270364, member: 5151"*as I understand it, cables are typically 16 or 32amp, not 20amp, though I might be wrong.[/QUOTE]
There is no such thing as a 16A cable, possible cables types are 13A, 20A, 32A and 63A. Normally, a 20A cable would be used with an EVSE that's designated 16A.
 

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Discussion Starter · #12 ·
[QUOTE="howartp, post: 270364, member: 5151"*as I understand it, cables are typically 16 or 32amp, not 20amp, though I might be wrong.
There is no such thing as a 16A cable, possible cables types are 13A, 20A, 32A and 63A. Normally, a 20A cable would be used with an EVSE that's designated 16A.[/QUOTE]

Hi Ralf, do you think my charging times have not changed after the upgraded cable as they are both drawing 20A from the unit? Because they are both faster than the standard charging lead (plugs into a domestic socket) that comes with the car. But there is no difference between the timing of them.
 

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I don't know anything about the Leaf. But if it genuinely has a maximum charging rate of 6.6kW, then that's a maximum of 27.5A. I'd also expect it to only charge at the maximum rate for the first part of the charge, as the battery gets closer to being full, the charging rate will drop.

So, it's quite possible that there is a difference in speed but it's relatively negligible.

It's also possible that your charger wasn't respecting the cable coding resistor and it was allowing 32A (actually, as above it'd be 27.5A) down the 20A cable, in which case you should take that up with the supplier as it's dangerous and could lead to a fire. You'd have to be sure that was the case, which it sounds like you're not.

If you have a multimeter, you can check the coding of both cables. Between the PE and PP piins, there should be a resistance of 680 ohms for a 20A cable and 220 ohms for a 32A cable. The rating should also be stamped on the cable and also on both plugs.
 

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Discussion Starter · #14 · (Edited)
Thanks Ralf, I think that is my next move.

Update - I went to a new free facility with type 2 semi fast chargers and used the 32A lead and went from 39%-80% in 70 minutes, almost twice as fast as it charges at home. The output on the charge station was the same as my home one, 230v/400V 32A 1 phase. This makes me believe the fault does indeed lie at home and that both leads are drawing 20A when in use. I will try and charge at this place again but use the old 20A lead to confirm if this is the case, as this seems a much easier solution than finding a multimeter and checking the cables.
 

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Discussion Starter · #15 ·
Problem solved. It was due to the charging unit at my flat, they changed something (they did not tell me what, but the unit remains the same with the 16A RCD). My 32A lead took my car from 31% to 80% in 75 minutes, compared to the old 20A which took 118 minutes for the same 31% to 80%.

Thanks for everyone's contribution, I know have a very quick home charging set up and feel justified in spending the money (145 quid) on the Type 2 lead.
 
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