Battery Cooling Fan - Renault Z.E. Forum
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post #1 of 31 (permalink) Old 06-03-2014, 05:46 AM Thread Starter
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Battery Cooling Fan

Has anyone worked out what is going on with the battery cooling fan.

Wife put the car on charge last night at 19:40 and ZE services reported a 21% charge.

I returned home at midnight and noticed the battery cooling fan was running.

Left for the bus at 7am this morning and the fan was STILL running. So either it has been running all night or it is just coincidence that each time I passed the car (7 hours apart) the fan was running.

End of charge notification (100%) came through on ZE services at 00:11.

I wonder how long the battery fan would have continued to run (probably forever until the charge lead was unplugged).

Seems a bit wasteful of energy.
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post #2 of 31 (permalink) Old 06-03-2014, 06:01 AM
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RE: Battery Cooling Fan

It is a Peltier cooler so not very powerful. My tests last year showed it was drawing 500 to 600 W. Yes, if it starts it will tend to run continuously while you are charging because the battery will warm faster than the cooler cools and it will continue to try to cool the battery.

What you are reporting does seem to suggest an annoying tendency to run on unnecessarily. It's wasted over 3kWh. You'd tend to think it'd have done its cooling by then. But the battery pack is a big lump of monolithic storage heater so no real big surprises.

It also vents the exhaust heat into the cabin, so some fraction of the heat rejected will make its way back into the battery again! Not the best design, perhaps!!

Best way to avoid this is not to let the battery get so warm before you begin charging. If you've just got back from a swift drive [in warmer weather] then let it stand and the battery cool down first. In the situation you describe, I'd have let it sit until I went to bed, then plug it in. But I tend to do that anyway unless I'm doing a 'short' charge in which case I unplug at 75-80% ish SOC before going to bed.

You don't really want to have the car charged to 100% and then sitting - if you're going to charge to 100% then best you time it so it completes charge just before you use it. Sounds like you might want to think about doing what I do, if you are after 100% charge.

Plugging in late evening is also beneficial in two other ways - most energy meters are cheap and only monitor current. As the voltage bobs up towards night time, as loads in the neighbourhood drop off, you will get more real kWh for the same indicated meter reading. Also, if you are 'eco-minded', less CO2 is generated by each kWh you draw after 12AM than earlier.
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post #3 of 31 (permalink) Old 06-03-2014, 06:10 AM Thread Starter
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RE: Battery Cooling Fan

Quote:
Originally Posted by donald
In the situation you describe, I'd have let it sit until I went to bed, then plug it in. But I tend to do that anyway unless I'm doing a 'short' charge in which case I unplug at 75-80% ish SOC before going to bed.
Thanks Donald. Situation may resolve itself anyhow. I am just waiting for the installation of my off-peak meter. I have installed my timer and it works great. My region seems to have a weird 'off-peak' period from 22:30 till 00:30 and from 02:30 to 07:30 thus making the 7 hours in total. This will not be confirmed until the meter is actually installed but by all accounts my charge will be starting at 02:30 in the morning so plenty of time for the battery to cool down.
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post #4 of 31 (permalink) Old 06-03-2014, 06:32 AM
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RE: Battery Cooling Fan

Bear in mind that you should avoid setting your timer to turn OFF charging. The charging protocol is not designed for this. OK to set the timer for power-up, but I would advise against setting the timer where it could power off the charging.
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post #5 of 31 (permalink) Old 06-03-2014, 07:00 AM Thread Starter
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RE: Battery Cooling Fan

Quote:
Originally Posted by donald
Bear in mind that you should avoid setting your timer to turn OFF charging. The charging protocol is not designed for this. OK to set the timer for power-up, but I would advise against setting the timer where it could power off the charging.
OK good point. I will set the off time for midday, that way we will always be unplugged and away. I use pre-heat in the winter and we are generally unplugging at 8.30am on a weekday. Thus I will be paying peak rate for my pre-heat but off peak for all my charging.
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post #6 of 31 (permalink) Old 06-05-2014, 05:30 AM
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RE: Battery Cooling Fan

600w for a fan? I'm lucky if it reaches 30w as it is quite a wimpy air mover. For 600w I'd expect to see a hurricane of dust behind the Fluence!

My charging timer controls only the pilot line, which goes live at 0005 BST and terminates 0820. My last 20 or so charges show the process completes after around 0405 +/- 30 mins depending on capacity when it starts. My average charged time is therefore a little over 4 hrs (despite the pessimistic guestimation of anything from 5-7hrs.

The 'charging protocol' cares nothing for how little you charege - as long as the sequence is followed with the pilot line confirming start up and shutdown the car is fine. I can appreciate interrupting the power by brute force without using the pilot line then there may be issues, but as long as the timer is not simply shutting off the power there are no issues.

I'm confused by your OP rates - Scotland uses SP's standard timing 00:00 to 08:30 and as I have a Radio Clock is unchanging even at the clock change as it auto updates.
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post #7 of 31 (permalink) Old 06-05-2014, 06:12 AM
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RE: Battery Cooling Fan

Quote:
Originally Posted by Buzby
600w for a fan? I'm lucky if it reaches 30w as it is quite a wimpy air mover. For 600w I'd expect to see a hurricane of dust behind the Fluence!
It is power driving the Peltier cooler, not just the fan.

Quote:
Originally Posted by Buzby
My charging timer controls only the pilot line
How have you done that? Have you DIY'ed the charging lead and inserted a timer on the one line, or did it come with the manufacturer's charge point? There were no such charge points available when I had mine installed.

I've still no idea what's going on with your full recharge in less than 5 hrs. Something is not as it should be.

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post #8 of 31 (permalink) Old 06-05-2014, 05:02 PM
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RE: Battery Cooling Fan

600w is a massive draw simply to provide cooling, and whilst you appear to accept this, I'd be avoiding this wherever possible.

The 'timer' is integral to the Rolec Wallpod, however a little investigation will reveal no standard timer can switch 32a so would be a risk of burning out. The professional way of controlling the charge sequence is to make use of the two control lines (the two smaller pins) one is the proximity sensor that detects the plug insertion, whilst the other initiates the the relay to turn the power on.



Never, EVER start or stop an EV charge by interrupting the supply in the way you suggest, it must be controlled to prevent damage.

On the Rolec, (which is permanently powered) complete with blue flashing LED, will on insertion of the tethered lead do only one thing. That is, show the plug inserted icon on the Fluence dash. It will not charge as the timer won't allow it until 0005. At this time, the contacts switch, the flashing LED changes from blue to green and the Fluence indicators flash confirming the charging has commenced. At the conclusion of the timeframe, the voltage on the pilot line drops and the car exits charge mode.

A number of the other domestic Chargepoints do not provide any timing mechanism, suggesting that it is up to the vehicle (or its app) to control it - the British Gas oval one frinstance. My original installers of the Wallpod refused to hook it up to my off-peak supply for this very reason - my radio TeleSwitch could manage switching 32a but the issue was bypassing the pilot line control, and firing in the 240/12v instantaneously then removing it, denying the car charger any element of control.

As to my charging cycles, I can confirm I still get a full charge from 5% to 100% in under 5 hours it has never taken longer
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post #9 of 31 (permalink) Old 06-05-2014, 06:11 PM
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RE: Battery Cooling Fan

600W is not so much for a Peltier cooler - they are not very efficient. It is probably generating 200W or so of actual cooling power in the battery for that much input power (minus fan and accessories), which is going to cool a mass of battery as it is very slowly. Still, there is nothing worse to Li batteries than heat to age them, so any cooling does help. Better than a Leaf!

Not sure what you mean 'in the way that you suggest'? I was trying to make sure ED did not set his timer to power off mid-charge. You can buy timers in any current capacity you like, the main issue is really whether they are carrying an inductive load before deciding what type of timer relay is possible.

An EV charging is not much of an inductive load, as inductive loads go, because the input power is first rectified and I would presume must be capacitively smoothed before being drawn on by the buck-boost circuit. On the brick lead, my power meter was showing a power factor of 0.98 during charging. Practically no reactive load at all.

Still, naturally I would equally not recommend powering off an EV mid charge, but it can't hurt once in a while because the circuits must be designed to tolerate it. It would be a design defect if the car was broken the first time there was a power cut! With a good design there should be no effect at all, but as a consumer one cannot really tell how good the charge circuit design is.

I've considered fitting a 40A timer several times, but each time I debate the relative benefits and, to be honest, I would rarely rely on it these days as I simply arrange to plug in and unplug at the appropriate times and that MO has caused no issues at all so far. So I'm not longer thinking about it and I don't think I'll be bothered. It's an oversight on CM's design, for sure, and I quizzed them on it when it was first installed. Their Leaf-centric view was that you'd set timed charging in the car, but they clearly didn't bother establishing how EVs on the market actually worked before they came up with a design without a timer. Marks out of 10 for your market research and design requirements-capture? Negative 20!

Getting a 4kW charge rate still suggests you're seeing very high volts at your charge point. I can see no other explanation if you are still getting good range from the battery.
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post #10 of 31 (permalink) Old 06-06-2014, 02:54 AM Thread Starter
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RE: Battery Cooling Fan

I have installed my timer on the DIN rail of the MCB which supplies my Chargemaster 'oval' chargepoint (similar to the BG model).

It cost me 40 from RS components and can switch 16A resistive load. Initially when I installed it, I didn't think it was working, as the chargemaster goes through a 3 minute 'checking' cycle when you power it up. Hence the reason ZE services reports my charge start time as 00:30. If anything I think this will have a detrimental effect on the chargemaster unit. I will avoid cutting the power mid-charge though, not because it worries me, more to do the fact that I need to keep the power on till I head out in the morning to get my 100% charge and subsequent pre-heat. The key thing for me is to start the charge whenever my cheap rate kicks in.[hr]
Quote:
Originally Posted by Buzby

I'm confused by your OP rates - Scotland uses SP's standard timing 00:00 to 08:30 and as I have a Radio Clock is unchanging even at the clock change as it auto updates.
I contacted Scottish Power about the OP rates and was advised it can be ANY 7 hour period between 10:30pm and 08:30am and in some cases the 7 hours is split into 2 periods. I was advised that the only real way to check is the active rate on my meter at given times. As my meter has not been installed/re-programmed yet I cannot really do this. Interesting you say that your clock auto-updated. I have had a smart meter installed for the last year and I can log in and get me half hourly data, etc. However my clock stays the same throughout the year. Annoying considering there is the technology to do it. If you are on ECONOMY 7 (the correct name for off peak now) the you get 7 HOURS off peak electricity per day. You cant be getting off peak form 00:00 to 08:30?

[hr]
Quote:
Originally Posted by electricdream
Hence the reason ZE services reports my charge start time as 00:30.
Sorry that should be 00:03 as I start my charge at midnight.


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