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Discussion Starter #1
This morning I plugged into a rapid. The car was at 20% SOC and battery temp was at 5 bars.

Strangely the car only ramped up to 75A and then when it went past the 55% mark it was gradually reducing down to 25A.

Usually when I charge and the car is below 55% the power output of the rapid is a constant 106A (can't remember the voltage). This then ramps down slowly.

Basically it took me 30 minutes this morning to charge from 20% to 73%. Usually this would only take me 20 mins tops.

But when driving home later on in the day I was curious. Will it behave the same as it did in the morning on the same rapid, it didn't. It ramped straight up to 106A and my SOC was at 30%.

Why did the charging session this morning output at a lower power. Is it the car restricting the power or the charger? Anyone else experienced this?
 

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Yes, I have experienced this variation in charging current between charges of similar starting SOC... I have no idea why.

I wondered if it was a software change. I have done over 400 rapid charges now on my Mk1 Leaf and so I feel I have a pretty good idea of how they behave... at least I thought I did but this has thrown me.

It used to be exactly as you describe... 106A to 396V then a ramp down after about 52-55% but like you I expereinced a charge last week at about 30% when the charge rate had already started the ramp down... long before it used to.

I have stopped looking at the charge current recently because it always did the same thing every time but with this I shall start to take note again and report back.

Any one else notice it?
 

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I have noticed quite a bit of variation from charger to charger. I think that some of the rapid chargers don't have quite the electricity supply of others. The guy at the Burnley Nissan dealer reckoned that this was the case and I'm certainly not qualified to contradict him. I thought that the Tunbridge Wells one was also rather slow, but it was quite a cold day when I was there in March.
 

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Is it not simply temperature related? Once you hit 7 bars on the battery temp gauge the rate of charge increases as identified in the manual
 

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Yes, there are distance related issues. I use the RC at Wessex Garages in Gloucester and they are about as far from the substation as you can get for 106A and even then that is a rare sight on their unit.
I charged at Gloucester Wessex once. Seemed rock solid around 54A. I just assumed some dealers didn't have the feed available for high current charging so the chargers were set up for a lower limit. Are you saying Gloucester Wessex sometimes runs at higher rate? (or maybe used to...)
 

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I think Rapid Chargers are one of the great mysteries of life. I was given a thermostat error the other day on the old machine at Hollingbourne services. Immediately a Tesla drive plugged in to the AC side and it worked perfectly. I suppose the cooling system isn't challenged to the same extent at 22kwh as it is for 50-odd.
 

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I think Rapid Chargers are one of the great mysteries of life. I was given a thermostat error the other day on the old machine at Hollingbourne services. Immediately a Tesla drive plugged in to the AC side and it worked perfectly. I suppose the cooling system isn't challenged to the same extent at 22kwh as it is for 50-odd.
It is worth checking the charger cool air intake filters above ground level for partial blockages when you get this thermostat error message. I have managed to start a charge twice with this.
 

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Discussion Starter #11
Could it depend on how much and/or how recently the charger has been used, to help prevent damage, overheating and such?
That's the only thing I can think of Paul.
 

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@Wowbagger Don't forget that with DC charging the conversion from AC to DC is done by the charger unit beside the bay. This will get warm. With AC charging it is different in that the car has the charger on board and does that conversion itself so with AC charging the box beside the bay just delivers the AC power and does little work itself.

This might explain why the box by the bay gets much warmer with DC than with AC charging and why it might be able to deliver AC when it is too warm to convert AC to DC.

I am just summising with this and have no specialist knowledge so I could be talking rubbish :eek:
 

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To be fair, the old Hollingbourne charger seems prone to the thermostat error. The epidemic which knocks lots of rapid chargers out at a time is the Ground Fault, often associated with wet weather. As a friend of mine said, a propos of the unsheltered fans pointing upwards at 45 degrees, "What could possibly go wrong?"
 

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Discussion Starter #15
It won't be long, the ground fault will soon arrise again.

Where are they with this permanent fix. I only thought they done a temporary one on a few units going back 6 months ago?
 

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The new chargers are a different design at the back. The upward-pointing fans have been replaced by some that seem to be pointing outwards horizontally.

If my pal is right and the problem is caused by water ingress from these fans, then putting some sort of cheap and cheerful plastic shelter (a bus shelter?) over the top of rapid chargers might be money well spent.
 

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Yes, to be fair my remark was at least partly facetious. I had some brief, but intensive, communications with Simon Crowfoot, the Man Dir of the Electric Highway, a few months ago, and he considered that it was "humidity" rather than simply raindrops falling in, which was causing the degradation of some critical component or other. How the newer machines have tackled this problem remains to be seen.

I have no knowledge, for the purposes of comparison, what percentage of petrol pumps are out of action at any one time. I would think that it's a pretty fair percentage, given that throughout the day many are used up to a dozen times an hour. The differences are, of course, that the vast majority of petrol stations are manned throughout opening hours, and the companies that operate them know that their profits will be hit if the percentage of broken pumps gets too high. It is therefore cost-effective for them to have round-the-clock teams on duty mending petrol pumps.
 
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