Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[2020_SRS_Commuter]

Hi, Im asking about my 2020 SRS, bought new in Sept 2020. I've put a bit over 50k miles on it. 

When it was new, I don't ever remember the battery thermal limit slowing me down. I used a highway section of about 28 miles to go to work and I could go 100 mph the whole way, sometimes going full power to 124 in bursts. This was in the daytime in Florida. Hot. Rarely I would hit the motors thermal limit but I don't ever remember the battery being an issue. The way home was the same, riding at night.

Now the highway portion of my trip is a bit shorter, 21.5 miles. I hit the thermal limit on the battery nearly every trip back and forth.
If I hold it to 90mph, no problem, I may hit the yellow by the end but its ok. If i try to hold it at 95 mph I will hit the thermal limit and get slowed somewhere around the 19-20 mile area of the trip. Faster than that, the battery thermal limit activates even sooner. I never see the motor get warm at all. If I keep it in the 80's there is no limiting issue.

If I was to try, intentionally, to make the motor thermal limit I would never get close. The battery limit would kick in well before that.

The battery pack performance seems to be normal otherwise, and the capacity is still about 11kwh or so. There is no difference in range that I can see at all. That's excellent, good as new.

So my question(s): Is that, thermally, normal battery response for those conditions? Am I asking too much? Maybe Zero changed the battery pack thermal limits in a firmware update or something? IDK. Just curious was other's experience with this is.



 

[Specter]

As a battery ages, it's voltages / oomph WILL drop.
Your trips demands have not dropped, ie you still need 45  kilowatts, just to throw a number out there..to hit 90 Mph, but your batteries ability to easily produce it have dropped.   What the battery can't give in volts, the system will make up for in Amps.  Plain and simple Amps = Heat.
When brand new, that 100 amp draw on your battery may have dropped the terminal voltage 12 volts under load.  Now that the cells are a few years old, it's dropping that terminal voltage 20 volts, again, just throwing numbers out there as an example.  So now, it's now pulling more amps to get that 45 KW your trip demands.  Amps = Heat.

You may not have hit your thermal limit in the past, but been darn close to it, and now that you are pulling an extra 20 amps, again just a number, you have pushed it past that boundary and are seeing it now.

Also, and just throwing this out there,  road conditions can make a difference too.  Back then the road may have been a lot smoother, so travel a bit easier, you ONLY needed 45 KW, now the roads are a few years shittier, (welcome to florida) and need 50 KW,  more amps - more heat.  Did you put on 50 Lbs since then?  fat asses need more power than lean asses   Maybe they also have a battery age derating thrown in the overall calcs for it too?  His battery is 3 years old, he don't need to be pushing it at 98 percent of it's limit at this age, lets tone his top end down a bit so it makes the full 5 years of warranty.  Instead of letting him cook them to 160 Degrees before being concerned, lets drop that to 150.  Airflow can get full of dirt / dust / mud daubers.  Oxidized aluminum don't bleed heat as efficiently as fresh clean aluminum in the air cooled case.

Many things can all add up to finally ding you.

Aaron

[2020_SRS_Commuter]

Nice!
Thanks for explaining that. Makes sense, as it happened over time.
Nothing else has changed. Same guy, same loads, same trip, same place, same times of day. Bike is clean and in good order.
So slower it is, until the next pack if there is one.