30kw DC fast charging and temp bars

Given the 30 kW seems to heat up faster during DC quick charging , I can easily generate 8 bars of temp after two successive fast charge sequences

What I never see during normal driving , is any reduction in temp bars even with under 60 mph driving , but sometimes I only see it after switching the car off and on again

Any comments , surely the battery should cool down a bit during moderate driving ??

Battery Pack will only cool noticeably if the outside temperature is at least 5F lower than the pack temp and even then it takes 8-24 hours to do so depending on how much the difference is. Longer if you charge the car or drive during that period.

Nissan chose a fully sealed pack, there is no air flow into or out of the pack so heat travels by conduction and radiation and does so very slowly.

I would say "more mass means more heat", but isn't the 30 kW pack about the same weight/volume as the 24 kW pack? I thought the individual cells were just a bit thinner and/or more efficient (same number of modules).

madscientist said:

Given the 30 kW seems to heat up faster during DC quick charging , I can easily generate 8 bars of temp after two successive fast charge sequences

Click to expand...

What do you mean by "the 30 kW"? Are you talking about 30 kW DC fast chargers or a 30 kWh battery pack?

kW and kWh are very different metrics. It's the same as confusing gallons with horsepower. Think of kW = horsepower, kWh = gallons.

If one charges at 1 kW (or 1000 watts) for 6 hours, 6 kWh came out of the wall. If it's at 6 kW for 1 hour, it's also 6 kWh. If it's 1 watt for 6000 hours, it's also 6 kWh.

(BTW, 1 hp = ~0.746 kW. And, many .gov sites says 1 gallon of gasoline=33.7 kWh.)

What are the actual battery temp readings per Leaf Spy? The temp gauge is apparently crap w/the huge overlapping ranges. See http://www.electricvehiclewiki.com/Battery#Battery_Temperature_Gauge.

higher energy density will obviously have greater heat issues since efficiency is only slightly improved year over year (yes its an ongoing process) but lets not compare your "Father's LEAF" to yours. I highly doubt there is a direct correlation between heat tolerance of 8 TBs in a 2011 and 8 TBs in a 2016

Which is why, until Nissan moves to a TMS or TRULY has a battery where temperature makes NO difference in degradation, there will not again be a Nissan EV in my driveway...