Charging behaviors and annoyances

[Ricksuiter]

I've been playing around with the charging on my 2014 Fiat 500e and have discovered a few interesting things I'd like to note. I've been using an open EVSE to vary the pilot signal and the goal is to be able to get the car to cool the pack in extreme heat while waiting (mostly) to actually charge later in the evening at off peak rates.

1) Mainly, the car will not accept a J1772 pilot signal of any less than 12A no matter what. Some of the level 1 chargers have a low power mode, which would be used if you knew a circuit had other loads on it. The Chevy Volt has this on the included EVSE, you could choose either 6A or 12A draw from the line. The Fiat will throw a "service charging system" error if it gets a signal of less than 12A and you have to start the car and shut it off to clear this error. It doesn't matter if it's 120VAC or 240VAC. Theoretically per SAE J1772 it should work down to around 6A, but it's possible that this is not enough power to heat/cool the battery let alone charge it at any rate so this may be why it won't work at lower power.

I was trying to reduce the current on 240VAC, but again it won't work with a 10A signal so 2.4 kW simply won't work even though it's more power than level 1. I suppose I could do 2.88 kW (12A at 240VAC).

2) With any signal over 12A, but with 120VAC connected it will only draw a maximum of 12A no matter what. Some vehicles can work with a "Level 1 plus" setting where it can draw 16A on a dedicated 20A circuit. This is 25% more power than you can get with a 15A circuit so for those using slow charging it had an additional benefit.

3) Maximum observed draw at 240VAC is about 27 amps.

4) The charger gets freaking hot! It's water cooled and the cooling fans move a lot of air, but it still gets so hot I can't touch it.

[rkw]

With any signal over 12A, but with 120VAC connected it will only draw a maximum of 12A no matter what. Some vehicles can work with a "Level 1 plus" setting where it can draw 16A on a dedicated 20A circuit. This is 25% more power than you can get with a 15A circuit so for those using slow charging it had an additional benefit.

Not sure I understand what you're talking about. The 500e will draw whatever it can from the external charger up to 6.6 kWh, and doesn't care whether it is plugged into 120V. From what I've read, the OEM Level 1 charger will supply power at either 1.1 kWh or 1.4 kWh depending on the circuit it's plugged into.
https://plus.google.com/u/0/+PaulLun...ts/1EsHuXyN8LY (see Pradeep Sanders' second post)

Also I've read that in extreme cold the 500e kicks on thermal management to preserve the battery (the car doesn't doesn't have to be plugged in). It's possible that it might also do it for extreme heat, although probably the temperature would have to be very high (enough to potentially damage the battery).

For topics like this, I suggest also posting on the Google+ forum: https://plus.google.com/u/0/communit...69255866480388

[Ricksuiter]

In the link they discuss drawing off of two 120V outlets. If you have two 120V outlets on different hots you can effectively get 240V (or 208V in the case of a commercial building) by using the two hots. This is highly against code to do, but such boxes exist:

http://www.quick220.com/220_catalog/...onverters.html

You will never find a UL marking on these.

From my experimenting the Fiat won't draw more than 12A with 120V applied via the EVSE. I fed it a 40A signal and it would only draw 12A. I also fed it a 16A signal (what you could draw with a 20A outlet) and it still only drew 12A. Anything lower than 12A and it wouldn't charge at all, it just gives a service charging system fault.

I primarily charge on my openEVSE at 240V at 20A (old REMA J1772 handle I got back in 2011 which is known to melt at 30A even though it's rated for it), but when I get home on a very hot day I'd like to limit to about 1kw, which is about enough to run the cooling for the pack, but I'd rather delay a significant bit of the battery charging until 11pm when I get a super off peak rate. The only way I can really do this is to use 120V.

This all might make sense though because it wouldn't really ever exist in a normal commercial product. In a home you would have primarily 15A 120V outlets and possibly some 20A 120V outlets. A 20A in a garage is common. Anything higher power is going to be 240V. The one exception might be a 30A 120V for a RV, but this is not common. The smallest 240V circuit you would find would be a 15A for something like a small air conditioner. Anything higher power would be something like a 30A 240V for a clothes dryer or 50A 240V for an oven or large RV circuit.

Also, the 1.2kW power of a standard 120V outlet is probably about the minimum that it would take to run heating or cooling on the pack plus actually charge it a bit. Still, it would be convenient if I could use 16A at 120V.

[scoops]

Does the 500e not condition the battery (when needed) if it's plugged in but waiting for the charge time to start? How about after the car is done charging?

[charrigan]

Does the 500e not condition the battery (when needed) if it's plugged in but waiting for the charge time to start? How about after the car is done charging?

With the car "off" thermal management will only function if charging is active. otherwise the car is in 'hibernation' mode until 3 weeks pass.

[Greg Elmassian]

Just out of curiosity, why are you trying to limit the amperage during charging? Man, the 120v level 1 at 12 amps is slow enough!

You are not saving any money charging at a lower rate or current.

Love to hear the explanation.

Greg

[Ricksuiter]

There are two wishes here:

1) I would like to be able to starve the car of charging power to roughly match the power required to run the cooling for the battery pack only. When it's 115 degrees out and the car has been sitting on black top in the sun all day I'd like to come home and get the cooling system to run, but not charge the car. I would turn up the power late at night when my electric rates are low. For the time being I've just been plugging it in to 120V at 12A, but it does net charge the car slowly.

2) In a situation where a circuit is shared with another moderately high current device such as a chest freezer in a garage drawing 12A would mean the breaker trips. I have not had this situation yet, but it could arise. The first gen Volt has a 6A setting on the included Level 1 EVSE for this purpose.

[Greg Elmassian]

So you are worried about damage to the battery when the car is sitting not charging and it is hot? I don't think you need to worry, you are neither charging or discharging.

I think I noticed that when plugged in, the car would cool or do something even if not charging, but not sure.

What about running the preconditioning a few times during the day? That should start the AC, and then cool the interior and then shut off, then it will start charging.

On the current draw, get a second outlet on a different circuit, why risk tripping a breaker and spoiling your food in the freezer?

Greg

[Ricksuiter]

I had a 2011 Nissan Leaf, it lost over 20% of its capacity in the first 18 months so I'm paranoid. The Fiat only cools when it's charging or the key is in the ignition and the car is on. I don't have Fiat Access and they won't sell me a subscription to it so the only way to run the car would be to turn the car on with the key in it and I can't do that in a safe manner in the parking lot at work.

I have a dedicated circuit at home, but it's entirely plausible to only have a shared circuit at a remote location, such as perhaps a plug that is on the same circuit as lights in a parking garage.

[Greg Elmassian]

If I'm not mistaken, the Leaf does not have a cooling system for the battery, so the heat from charging and discharging will shorten battery life in general. But since your Fiat has this cooling system that does indeed operate during these critical times, I think you should let reason overcome your paranoia . You are comparing apples to oranges.

I'm wondering if there isn't some way to crack the issue with Fiat to allow the access app to work... I've heard that they won't let you have one if the car is over 3 year old.

I had to work to remove my 2014 when I got my 2017, the system got very confused.

Greg