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cthombor:
kingdragonfly: Note the Nissan e-NV200 is based on the Leaf.
It has active cooling: the A/C runs whenever it fast charges. However at least one reviewer thought "this system is mostly ineffective at cooling the pack, but likely somewhat capable of equalizing temperatures within the pack."
https://insideevs.com/heres-nissan-employs-active-air-cooling-e-nv200-battery-pack/
AFAIK -- from observation -- the active temp control (cooling or heating) on the battery in my 2014 e-NV200 only kicks in when I'm AC-charging. But if I replaced its failed PTC resistive heater I'm pretty sure it'd work well at pre-heating, whether or not I'm charging or just idling in Drive mode. Maybe even while parked in Accessory mode (but doing that for extended periods is a *bad idea* becuz it drains the 12V battery).
As with a Leaf, repeated fast charges of my e-NV200 n a single day will raise its motive battery's temperature to the point that it works rather inefficiently.
Today I ran a few more experiments on my e-NV200, with the goal of figuring out how best to keep its batteries from overheating when travelling more than 300 km.
Finding #1: the active cooling (a heat pump plus a fan) is operating during a DC fast-charge, but (when the ambient air temp is about 20 degrees) the batteries still gain about 2 degrees during a fast-charge to 80% SOC.
Evidence for finding 1: See below for a charge from 22% SOC to 82% SOC, sensor 1 initially at about 26 degrees, rising to somewhat above 28 degrees, then dropping slowly after the charge rate drops below 15 kW.
Additional evidence for finding #1: see below for a 40-minute charge from 26% SOC to 40% SOC, with the first 18 minutes being a DC fast-charge (initially 44 kW, dropping to 20 kW) and then about 20 minutes of AC slow charge (1.5 kW: this being 8A downrated by 10% in my mode-2 EVSE, multiplied by 230 VAC). Note that the battery temperature started to drop after initially rising a couple of degrees, and that the slope of the temperature-drop is not hugely different between the DC fast-charge and the slow-charge.
Finding #2: you can use a DC fast-charger to lower your 24 kWh e-NV200's battery temperature by charging it above 80%, but it's rather expensive -- and you'll annoy anyone else who wants to use that charger. See below: a 14-minute session on a $0.25/min, $0.25/kWh fast-charger; total charge delivered was just under 1.0 kWh for $4.88.
Finding #3, The battery temperature drops about 4 degrees per hour when charging, if the ambient temperature is about 20 degrees. See the fast-DC charge above, and see also the 20-minute AC-charge at the end of the second screenshot in this posting.
Finding #4, the active temp control consumes about 500W when the battery temp is above 25 degrees. From below: a 1.5 kW AC charge delivers only about 0.9 kW to the batteries when they're hot; but the green and blue lines nearly coincide in the second half of this charging session (which was much quieter than the first half, as the fan-noise had been quite loud). At a very rough guess: 50W for the fan, 450W for the heat-pump, and maybe 100W for the inverter (assuming it runs at above 90% efficiency, and also noticing that the green-blue difference in the second half of the session is usually 0.0 kW, 0.1 kW, or 0.2 kW).
Moral #1: if your batteries are getting hot, you might fast-charge until they cool down. Indicative cost when the ambient air temp is roughly 20 degrees: ($0.25 / minute)*(15 minutes / degree) = ($3.75 plus 15 minutes of waiting-around) per degree of temperature drop. Alternatively: you could ask someone for access to their AC power point. That won't speed the temperature drop, but you won't be "renting" the (very spendy!) DC fast-charger while you wait for your batteries to cool -- and it's no faster than an AC slow-charge when your SOC is above 90%.
Moral #2: the best place on the NI for me to stop for a battery-cooling session in my e-NV200 is at the top of the Desert Road at night. The ambient air temp is reliably below 10 degrees, and the stars are spectacular. But YMMV, as you're unlikely to have an AC power supply.
Question: can you draw 8A from the 100 VAC 60 Hz inverter in an ex-Japan e-NV200 while it's AC charging? If so then you can (lossily!) have its motive battery "charge itself" (with the fan and heat-pump working to drop its temp) -- well that's a lossy process so you wouldn't want to do that when you're trying to cross the Desert Road, but you could try it after a DC fast-charge session to 80% that left your batteries overheated. The mode-2 EVSEs normally used with Leafs and e-NV200 will run all the way down to 100 VAC; and at 8A (derated by 10%, so actually 7.2A) that'll be only 720 W -- barely enough to run the heat pump and fan, so quite efficient really as a way of lowering the temperature of an e-NV200 using its motive battery as the inverter would hardly be producing any charging current. Worth a try perhaps, but I can't do it, because I had pulled the 100 VAC 60 Hz inverter from my e-NV200 to save some weight -- has a heavy steel mounting bracket... and annoyingly found that I had to leave its neighbouring junction-box in the circuit to avoid tripping HV DC fault codes, so I didn't gain much space. The only use I ever found for that inverter was charging a laptop -- as their power supplies are designed to work on any country's AC supply (including Japan's 100 VAC)...
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