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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: Kappi on August 23, 2020, 08:13:52 PM

Title: Solved: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Kappi on August 23, 2020, 08:13:52 PM
Hey everybody,

on my '17 SR 13.0, I have this weird behavior when travelling at a constant 100 kph.
 When I am cruising at higher speeds, the SOC starts to fall rapidly and the remaining range display drops with a factor of about 2 km for each km travelled.
 On a calm day with flat terrain, the bike will give me about 80 km of range at 100 kph. Once slowed down to city speeds, the remaining SOC will stay konstant for about 4 km, sometimes even rebound by 4-8%.
At lower speeds, though, below 80 kph, the range estimation works fine and I'll have about a range of 120 to 130 kms at a constant 80 kph.

From what I gather from the app, range collapses as soon as the discharge rate reaches or exceeds 0.8 to 0.9 C.

Is this behavior normal?

Thanks for your feedback

Kappi
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: stevenh on August 23, 2020, 10:39:26 PM
It's normal for range to drop quickly as speed increases.  My SR/F will pull a constant around 75KWH/Mi at 40-45MPH, and 130-150KWH/Mi at 75-80MPH, so the range will drop like a brick at higher speeds.  The estimation just tries to do it's best based on what you are currently doing.

Steve 
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: AutoE on August 23, 2020, 11:51:42 PM
How many miles/km on it?  Post you logs here or PM me. 50/50 your battery is failing if SOC is "rebounding". If you can take a more "spirited" ride, do so. We've seen battery drop from 90% to single digits in 10-15miles, then bounce back to over 50%. All needed replacement.
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Kappi on August 23, 2020, 11:56:42 PM
It has about 4k miles on it. Will download logs and post the next chance I get.
I have taken more spirited rides, but temp control will reduce motor power after 3 miles at 100+ mph.
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: DonTom on August 24, 2020, 01:53:00 AM
The estimation just tries to do it's best based on what you are currently doing.
IMO, range estimates are so useless (especially where there are a lot of hills) that they shouldn't even exist. It can be so misleading if going down hill a lot with the wind in your direction that when you go back, you may run out of range when you discover your range is a tenth of what it said it will be.  I find it is best to not even look at the range left indicator  and do the math in your head based on the SOC & conditions and knowing if you will be going mostly up or down hills and such.

-Don-  Reno, NV
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Richard230 on August 24, 2020, 02:30:35 AM
Also, if you are riding in cold temperatures, your range will drop noticeably faster then in warmer weather. I think you will notice a drop in range, and corresponding SOC per distance traveled, at anything under about 15 degrees C.
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Crissa on August 24, 2020, 05:52:46 AM
And when you get near the end of a charge, SOC can be less dependable.

-Crissa
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: AutoE on August 24, 2020, 12:08:43 PM
We had batteries with bad cell(s), cell tap issues, etc from under 1000miles.
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Gains on August 24, 2020, 05:35:52 PM
I suggest to check what your real range is by riding the bike till the SOC is nearly 0 on a flat highway in both directions. When I tested my bike I started with headwind and around 55% I turned back.
If you do this in ECO mode with full throttle you will have a constant speed of 113 km/h and you schould be able to ride more than 100 km. ( Zero stated a highway range of 130 km for an sr 13kwh in 2016 ) if you don t have top or sidecases or a big windscreen on your bike.
The calculation of the range is based on how you have been riding the last few km and the bike can not predict what you will do the following km. It is only accurate if the conditions like terrain ,wind ,ridingstyle etc remain the same,
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Kappi on August 24, 2020, 09:37:01 PM
I managed to pull the logs.

What I could find so far is a reoccouring error "Low Chassis Isolation", showing up while charging from various cells.
I parsed them but can't upload the txt file due to size issues.
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Kappi on August 25, 2020, 01:30:56 AM
Range test:
60 km from 98% SoC to 12% SoC in Eco mode at a constant 113 kph. Calm day, flat terrain.
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Gains on August 25, 2020, 02:45:38 AM
That would mean that you could make 70 km on a charge,at 113km/h. My wife 's 2013 with 9.5 kwh does better.
Do you give it time to balance from time to time? If you unplug after charging and the green charging light stays on the battery is balanced.
You can also check the voltage of your battery at 100% and at 0%

Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Kappi on August 25, 2020, 02:56:59 AM
That would mean that you could make 70 km on a charge,at 113km/h. My wife 's 2013 with 9.5 kwh does better.
Do you give it time to balance from time to time? If you unplug after charging and the green charging light stays on the battery is balanced.
You can also check the voltage of your battery at 100% and at 0%
Thanks for your reply, Gains.
Max pack voltage after charging was 116,821 V, cell imbalance 4 mV.
After the ride, pack voltage was 94.807 V, cell imbalance 36 mV.
Yes, I let it balance, usually the app show 2-4 mV after charging.
The app also said that I had used 8.14 kWh for my test ride (full to empty).
If that 8.14 figure is correct, that would really bring me cloe to your wife's S.
Now I am waiting how much charge the battery will accept over night (OBC with Kill-A-Watt meter)

Update:
Full overnight charge was 11.81 kW from the wall
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: motorrad36 on August 26, 2020, 08:23:22 PM
Get your logs to zero and start a warranty claim, sounds like your battery has a bad cell or something...
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Gains on August 26, 2020, 10:20:25 PM
Get your logs to zero and start a warranty claim, sounds like your battery has a bad cell or something...
I agree ,there seems something wrong with the battery or the BMS
Since your bike is a 2017 ,you still have warranty on the battery.
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: DonTom on August 27, 2020, 01:37:22 AM
When the battery was crapping out on my Zero DS 6.5, the difference in range was most noticeable at the higher speeds. At very slow speeds, such as on a 40 mile unpaved road, I didn't really notice any difference in range, but I think it was reduced a bit there also, but not nearly as obvious as at higher speeds.

What was also very obvious is my charge times was much LESS. Just as if my 6.5 KWH battery was a good 3 KW battery. It took less than half the time of normal to get to 100% charged. Also, regen would appear to charge the battery much better, when looking at the SOC, which probably helps explain the good range at very slow speeds. Regen would add as much range as ever, as the SOC increases were double and very noticeable as I was going  down hill at slow speeds.

Another symptom was if I got back at 5% SOC and had to slow down a lot for the last mile (1.5 km) or so, the SOC would start to increase to perhaps 15% soc or even more if I just let the bike sit.

Now it has a new 7.2 KHW battery (replaced under warranty) and what a difference!  The difference is most noticeable on the freeway, where my range is now several times what it was with my old battery.

The battery crapping out during the warranty is good, especially if you're getting a free upgrade as I did.  My DS ZF 6.5 is now really  a ZF 7.2!

-Don-  Reno, NV
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Kappi on August 27, 2020, 11:51:21 AM
Thanks for your replies folks.

I contacted my dealer and he sent the logs to Zero.
The increase in charge level is something I noticed, too.  Parking the bike or returning to slow moving traffic after a ride on the Autobahn, the SOC will either stay constant for several km, far exceeding the "expected range per percentage point" or start to increase again by several percent. Also, after a trip of using about 45% SOC and then letting the bike rest for a day without charging, the range indication will just drop when ridden again. I had a trip the other week of 25 km country roads, max. speed about 80 kph with half of it being towns with 50kph, that took me down from 58% SOC to  10% SOC after the bike had been parked overnight without a recharge.

Lets see what happens. I'll update the thread once I get news from the dealer.

Kappi
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: MBldc on August 27, 2020, 01:45:46 PM
SOC on my DS14 (where I kept an old Firmware Version as long as I owned it) behaved more like a coulomb counter, even under heavy load it did not drop unproportional. But at the same time, Power was sometimes limited even at more then 50% SOC, depending on battery temperature.
With my SRF, it is different. When driving WOT (especially Autobahn > 130Km/h), SOC drops more rapidly, than Energy Consumption would explain for. Then letting the bike sit for a while or just Power Cycle, SOC suddenly rises sometimes 10% and then decreases as expected when driving again. My guess is, that newer Firmware Versions somehow calculate the usable SOC taking the actual power demand into account (similar to Range Estimation). Beside that, Power seems to be limited only at lower SOC with newer Bikes, so it behaves more predictable especially when overtaking on country roads, which sometimes scared me on the DS. You never really knew if it would allow you for that..
Title: Re: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Kappi on September 25, 2020, 09:54:57 PM
Update: Positive Heads up to Zero and my dealer. Sounds like I'm getting a new battery 👍. Don't know yet what exactly went wrong with the old one but will post update as time comes.
Title: Re: SOlved: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Kappi on October 09, 2020, 01:42:17 AM
Problem solved. New battery installed.
The range difference is great :)
Title: Re: SOlved: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: DonTom on October 09, 2020, 01:52:06 AM
Problem solved. New battery installed.
The range difference is great :)
Great!  But did  they install a new 14.4 KWH battery or just another 13 KWH?

-Don-  Reno, NV
Title: Re: Solved: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Kappi on October 09, 2020, 02:08:49 AM
Hi Don,

they installed a 14.4 kWh monolith.
Title: Re: Solved: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: DonTom on October 09, 2020, 04:12:35 AM
Hi Don,

they installed a 14.4 kWh monolith.
It's nice to have the battery crap out during warranty, especially when they only have the larger battery available.

Now if only both my batteries  can hurry up &  crap out in my 2017 Zero SR! :)

-Don-  Reno, NV
Title: Re: SOlved: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: idle on October 10, 2020, 01:12:49 PM
Problem solved. New battery installed.
The range difference is great :)
Very glad to hear this!

Attached are my own worries, I remember the days when my '16 DSR had 120-140 on its range at full charge, and granted I did less highway miles back then, but I've also experienced quicker charging on the stock charger, and it just *feels* like lowered capacity.
Title: Re: Solved: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Kappi on October 10, 2020, 11:29:01 PM
Hey Idl,

65 miles expected range doesn't sound to bad. Was your last trip before charging on the interstate?
Just as an example:
My old 125 cc had a 12 kw engine, with 12 kw being the theoretical kinetic energy the engine would deliver. That bike was physically a little bit smaller than the Zero.
With this amount of kinetic energy, the bike could travel at around 65 mph (top speed).
Let's assume that the SR is comparable in cross section and wind resistance.
If you consider that the usable energy output in the 13kwH monolith is somewhere around ?11.6? kwH, which then has to be transformed into kinetic energy encountering losses like friction and heat, an SR travelling at around 60 mph would consume that amount of energy in 60 minutes or less, thus depleting the battery pack.

My point: If your prior trip was anywhere near interstate speed, 65.5 miles or range sounds realistic.
Title: Re: Solved: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: TheRan on October 10, 2020, 11:39:03 PM
You can't really compare them like that, there are plenty of 11kW 125s that can hit 70-80mph (think I got 76 out of my Duke) and they have much greater energy losses through the drive train. According to Zero the 14.4 will get 90 miles at 70mph which comes out to 81 miles for the 13kW/h.
Title: Re: Solved: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: Kappi on October 11, 2020, 11:15:43 PM
That's a valid point. I was simply making a rough comparison.
Do you know under what conditions the range estimates are measured?
I think I read somewhere that they are beased on a dyno rund with esitmated drag accounting for a tucked rider.
Does anyone now more?
Title: Re: Solved: Question for the battery hacks: Plummeting range / SOC at highway speed
Post by: TheRan on October 11, 2020, 11:19:06 PM
They're done on a dyno but the drag estimate is sitting upright, that's why the SR/S has the same specified range as the SR/F.