Author Topic: Range Variation with temperature change..  (Read 2249 times)

Gavin

  • Brammovangelist
  • *****
  • Posts: 2652
    • View Profile
    • Sol Power.  BrammoBlog
Range Variation with temperature change..
« on: March 15, 2012, 03:10:55 PM »
Ok...at first I thought there was little battery use variation between cold and warm....

But I now realize I was comparing cold and slight less cold:)

I was comparing riding at 20 degrees and riding at forty degrees...

With my type of riding (quick suburban riding)...I was getting around 32-33 miles on a charge at 20 degrees...and around 33-34 miles at 40 degrees. So not really a big difference.

I've been riding at 70 degrees the last couple of days and I'm seeing around 38-39 miles of range...5-6 more miles of range.

So, while that's not going to suddenly let me ride cross country on the E...well it is a significant increase...

Will do some "formal" testing this weekend...

G
« Last Edit: March 15, 2012, 03:46:30 PM by Gavin »

Brammofan

  • Administrator
  • Brammovangelist
  • *****
  • Posts: 3257
  • Following the momentum of Enertia
    • View Profile
    • Email
Re: Range Variation with temperature change..
« Reply #1 on: March 15, 2012, 03:36:09 PM »
Nice to know.  Looking forward to your formal testing. 

It's been so great in KC this week.  I've ridden every day so far.  My range has been pretty consistent.
The Brammoforum Wiki is still active: http://www.brammoforum.com/wiki

protomech

  • Brammovangelist
  • *****
  • Posts: 1987
    • View Profile
    • ProtoBlog
Re: Range Variation with temperature change..
« Reply #2 on: March 15, 2012, 03:58:21 PM »
Valence claims -10C to +50C discharge for the U1-12XP batteries in the Enertia. They show roughly 82% normal capacity available at -10C (14F), 90% capacity at 0C (32F), 100% capacity at 10C (50F).
http://www.valence.com/sites/default/files/images/XP_Module_Datasheet__1.pdf

EIG makes the pouch cells in the 2012 Zero bikes, they claim -30C to +50C discharge but don't provide temperature curves. If it's usable at all at -30C then it's probably pretty decent at -10C, and that's as cold as I'm likely to ever ride : P
1999 Honda VFR800i | 2014 Zero SR
Check out who's near you on frodus's EV owner map!
http://protomech.wordpress.com/

Vibetrippin

  • Empulse Guru
  • ****
  • Posts: 139
    • View Profile
Re: Range Variation with temperature change..
« Reply #3 on: March 15, 2012, 04:05:14 PM »
Those batteries may be good at -30 but I'm not.

Gavin

  • Brammovangelist
  • *****
  • Posts: 2652
    • View Profile
    • Sol Power.  BrammoBlog
Re: Range Variation with temperature change..
« Reply #4 on: March 24, 2012, 04:07:29 PM »
Ok...so I do the same commute everyday...usually on the weekends also...sadly work OWNS me....sigh

so I know this route well...and how the bike works on this route...

My ride in is usually in the 30's or less...lately it has been near 40...

I did do a little experimenting lately...and this is what I am seeing...

During the Fall and Winter I was always getting to the hospital garage at 85% charge...ALWAYS...weird....5.2 miles, 15% charge used.

Last week I came in a little differently...not the route, but the speed. I usually ride right at 5 mph over the speed limit...everyday...every road...that day I drove at exactly the speed limit the whole way...almost killed me :)

So I get to work...Boom...89% charge...as they say, speed kills...battery

So today I ride in and it is lovely...I never ride TO work in these temps...this is bike riding temperature...



I ride my usual style...5 mph over speed limit...get to work...88% charge...

So I can get more miles if I only ride in warmer temps or if I slow down :)

off for a ride....bye

Gavin

Gavin

  • Brammovangelist
  • *****
  • Posts: 2652
    • View Profile
    • Sol Power.  BrammoBlog
Re: Range Variation with temperature change..
« Reply #5 on: March 24, 2012, 05:41:17 PM »


Nice little ride...

Stopped at 50 percent to take a picture...on pace for 44 miles??

Easily the best range I've seen...

Guess warm weather does help

G

FreepZ

  • Brammovangelist
  • *****
  • Posts: 776
    • View Profile
    • Empulse Experience
    • Email
Re: Range Variation with temperature change..
« Reply #6 on: March 24, 2012, 10:06:05 PM »
Err...

50% x 2 = 100 %
16 miles x 2 = 32 miles.

I'm not sure where the 44 miles range comes from. Perhaps I'm missing something?
:-\

In any case, fantastic news about range extending warm weather! I'll be curious to see if the range changes when it gets really hot.
« Last Edit: March 24, 2012, 10:07:46 PM by FreepZ »
Richard #935 #595 #44

Gavin

  • Brammovangelist
  • *****
  • Posts: 2652
    • View Profile
    • Sol Power.  BrammoBlog
Re: Range Variation with temperature change..
« Reply #7 on: March 24, 2012, 10:56:56 PM »
T = trip miles

Range = bike's guess of how much more distance you get

So I had driven 22.3 miles to get from 100 to 50...

G

Gavin

  • Brammovangelist
  • *****
  • Posts: 2652
    • View Profile
    • Sol Power.  BrammoBlog
Re: Range Variation with temperature change..
« Reply #8 on: March 24, 2012, 11:47:40 PM »
Get home...hoped to put 40-50 miles today...but hung out at my brothers listening to music longer than I planned...

So get home after 34 miles of riding...

Interesting point...as I've said before ... Bike very accurate in battery drain til 40%... Then not as accurate.

So I get home with gauge reading 17 %... But when I go to charge it tells me, before I've plugged in, that I still have 31%...not sure which is right...



Gavin

Phantom

  • Brammovangelist
  • *****
  • Posts: 441
    • View Profile
    • Email
Re: Range Variation with temperature change..
« Reply #9 on: March 25, 2012, 06:39:35 AM »
In my experience, the 31% is the more correct number.

During a ride, I can go fairly fast to bring the reported remaining battery charge to 15%. As I roll up to and wait at a stoplight, I can see the remaining charge climb back to 28%, for example.

I think the software projects your remaining SOC based on your previous speeds to act as an early warning system that you might be cutting it close to running out of charge.

I have also noticed that my Enertia gets better range in warm weather.
« Last Edit: March 25, 2012, 07:08:23 AM by Phantom »

FreepZ

  • Brammovangelist
  • *****
  • Posts: 776
    • View Profile
    • Empulse Experience
    • Email
Re: Range Variation with temperature change..
« Reply #10 on: March 25, 2012, 03:02:33 PM »
Couple of questions:
  • When does the trip meter reset? Every time you charge, when you press a reset button, or in some other way?
  • Is the range estimator ever accurate? I would have thought that if you made 22 miles with 50% SOC, then if it's using your riding style to calculate range, it should have estimated 44 miles, just like you said. If, however, it's using it's own energy consumption estimates, then I suppose it will only be accurate if you ride the way Brammo expects you to.

I know that in my van, I can get an mpg number that is averaged since the last time I reset the counter. Using that mpg value and the remaining fuel, the computer can calculate the estimated range. It's simple and predictable. I know that if I significantly change my driving style without resetting the counter, I'm going to get an inaccurate range, but in general it works very well. It seems that there is more going on with the Enertia's range estimator.
Richard #935 #595 #44

Gavin

  • Brammovangelist
  • *****
  • Posts: 2652
    • View Profile
    • Sol Power.  BrammoBlog
Re: Range Variation with temperature change..
« Reply #11 on: March 25, 2012, 04:37:25 PM »
You have to push a button to reset the trip mileage.

Mmmm, it gives very good estimates when full...not so much when low on charge...

Hoping the new battery improves this...

Gavin

Phantom

  • Brammovangelist
  • *****
  • Posts: 441
    • View Profile
    • Email
Re: Range Variation with temperature change..
« Reply #12 on: March 25, 2012, 04:54:58 PM »
  • Is the range estimator ever accurate? .

Probably rarely, but I have not tried to test it. With so some many factors that affect range, I would not trust it to be accurate, but merely use it as another data point.

When I go to work, it is mostly downhill, back home is mostly uphill as you would expect. I can adjust my riding style and speed to get more range if I think I need it. I typically re-charge when I am at 35% to 45% SOC.