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[Булгаков]

So I'm stuck on the side of the road in the heat, with a battery that I can't charge due to thermal interlock. (I hope there's no other problem).

I rode 40 miles, then charged, then 40 miles, and charged, then I rode 57 miles, and now I cannot charge. It's saying 127deg F, and the dash shows no battery status, just like when the BMS died before.  With they key on I get BMS LED 1&4 blinking, with key off, only led 4 blinking. The dash showed 17% remaining before I parked.
All charging at 6.6kW, all driving 55-60mph .

What speed are others able to consistently drive on road trips?

[evtricity]

My road trip speeds are pretty variable (35-70mph) but tend to have longer breaks (group rides do that).

Unfortunately you'll need to wait until the battery temperature gets to ~122F (50C) before you can charge again. Then you'll need to monitor the battery temperature when charging to make sure it's not being pushed up (it should stay about the same or drop very slowly when charging at 6kW). You'll need to take it easier on the throttle for the rest of the trip (high current is what heats the battery, so hard acceleration is the primary heat generator, and then consistent higher draw - like freeway running).

What's the ambient temperature there?

[Булгаков]

Currently it is 38c/100f - typical southern US summer.

Yes, I think if I can get it to enable charging I might try even charging at only 3.3kW just to hope I don't get stuck again.

I thought I was driving lightly but I guess the battery disagreed with me.

[MrDude_1]

I would pour water on it...

[BrianTRice@gmail.com]

There's not much to recommend traveling at high temperatures. The Zero doesn't have a high-powered cooling system built in or much room for one.

- 55mph seems to be the best speed for dissipating battery heat, combining a reasonable amount of air flow and a relatively low drag.
- Charging builds up heat if it's above 4kW; so reducing your charge rate to 4kW should alleviate some of the charging-related heating.

Traveling at 55mph and charging at 4kW, though, will limit your daily travel to maybe 300 miles per day, though. You can travel more quickly in the early morning and in the evening but that risks wildlife and car encounters. On the other hand, longer charge times might allow you to get some real naps in.


I should say that 4kW with the SCv2 is achievable by disconnecting one unit from a 2-unit installation, but reconnecting that unit when the battery can handle it should be done while the bike is de-energized.

[togo]

Also charging to 90% generates less heat than charging to 100%. Internal resistance increases.

If you monitor battery temp and it approaches 50C/122F, it's better to ride at 55-60 mph to cool the battery, it cools fastest when there's airflow.

[Electric Terry]

Yes repeated cycles of highway riding and fast charging can eventually overheat the battery.  A few things that can help:

1) If traveling in summer, try to ride at night when its cooler and the sun isn't shining on the black battery case or the black asphalt below which radiates up into the battery

2) don't use the onboard charger, its placement is terrible and much of the heat goes right into the battery

3) riding slower helps in 3 ways -
      a) lowering the discharge rate and hence the heat produced
      b) giving you more time to dissipate the heat for the same distance travelled
      c) giving you a more efficient watt hours per mile, so your total trip requires less charge/discharge cycles

4) Upgrading to a newer model Zero helps in 2 major ways

     a) increasing the total battery capacity of the bike means the C rate of discharge and discharge is less for the same speed of travel and charging
     b) with the exception of the 2015 battery increase in size, each battery improvement has also gained a more efficient design that has less internal resistance, meaning less heating for the same power output

So combining those two and a 2017 13.0 will have much less heating than perhaps a 2014 11.4 for example.  For most people it's not an issue, but for those who are traveling and supercharging, transferring the supercharger to a newer model year bike will be the most significant thing you can do to reduce battery heat if you can't modify your riding speed any more.

5) Adding an aerodynamic fairing - this will be the same thing as riding 40 mph instead of 70 mph according to what your battery sees.  All it knows is that its now only having to deliver 7500 watts instead of 15000, meaning 2 things.  You get to go twice as far with half the C rate of heating.  However a fairing might prevent some of the air cooling effect, the benefits will far outweigh that

6) And as Tony mentioned above setting battery limits also help.  Charging to about 80% and discharging to 20% can really help prevent battery heating.  If you need to charge higher than 80% slow the charge rate down the higher you go.  And if discharging below 20% ride slower and slower.  Riding hard the last 20% will really heat the battery fast.

[togo]

Thanks, Terry.

[BrianTRice@gmail.com]

I'll add Terry's experienced recommendations to the wiki!

[MrDude_1]

For the record, I was not joking about the water. it WILL cool off the battery case, and therefore the battery much faster. the motor too...
just set the hose to mist, or even a spray bottle works great... but a waterbottle will work in a pinch.

[BrianTRice@gmail.com]

I tried to make a table out of this:
http://zeromanual.com/index.php/Usage#Hot_Weather

[togo]

For the record, I was not joking about the water...

Battery Cozy becomes swamp cooler?  Fabric means more surface area, means more evaporation.  Add a fan for more effectiveness if it's dry. 

We should make an effort to update PlugShare and other charging reporting sites/apps to include availability of water in the description or the amenities section, both for human consumption and battery cooling.  Especially refrigerated water.

[Булгаков]

Thanks for the advice. Unfortunately, here it seems that this just a plain limitation for me.

Outside of a large city, most charging stations are more than 50 miles apart, and often are daytime only (businesses, dealerships, RV parks) so nighttime riding is not as much of an option, nor is just riding from 80% to 20%, and even 55mph is sometimes dangerously slow on these roads.

104-108F / 40C temperatures really limit the EV options here. I wonder if Zero will follow the example of the Nissan Leaf and improve battery cooling for southern US heat?

I think perhaps I will only be able to take road trips in winter?

[Булгаков]

Also, I wanted to add that even when the temperature had reduced to 118/120F, charging at 3.3kw eventually raised it again until thermal interlock again.

Perhaps at 100-104F ambient temperature, thermal equilibrium is lower than .4C ?

[Cama]

Also, I wanted to add that even when the temperature had reduced to 118/120F, charging at 3.3kw eventually raised it again until thermal interlock again.

Perhaps at 100-104F ambient temperature, thermal equilibrium is lower than .4C ?

I guess in that  case, you used your onboard in addition to the 3.3kw-charger-modul?

We saw less raising temp when we didnt use the onboard while fast charging (7,2 kW) like Terry already wrote.