ElectricMotorcycleForum.com

Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: MichaelJohn on December 25, 2017, 10:21:40 AM

Title: Faltering acceleration on partial charge after sitting
Post by: MichaelJohn on December 25, 2017, 10:21:40 AM
Since the change in plugged/unplugged protocol I have been leaving the bike partially charged so it had been sitting at 74% for a couple of weeks. I took it out for a short ride without charging it because I figured after a few local errands I would be near the magic 60% level. When I gave it full throttle it briefly started to accelerate and then hesitated and just stopped accelerating. At first I thought I had lost a couple of teeth on the belt but once I slowed down and accelerated slowly it seemed to be OK. I tried accelerating hard again and the same thing happened. Then I accelerated slowly to a higher speed and it seemed to be lacking top-end power. I went home, charged it overnight and the next day all was well. I am not going to let it sit anymore and then take it out with a partial charge.
Title: Re: Faltering acceleration on partial charge after sitting
Post by: NEW2elec on December 25, 2017, 07:50:55 PM
Was it very cold?
Title: Re: Faltering acceleration on partial charge after sitting
Post by: MichaelJohn on December 25, 2017, 10:56:59 PM
I think it was in the low 40s (5°C). It is been getting into the low 30s here at night.
Title: Re: Faltering acceleration on partial charge after sitting
Post by: KrazyEd on December 26, 2017, 09:38:36 PM
Electric vehicles in general begin to lose full power as soon as the battery voltage starts dropping.
Not anything really noticeable until you get to the lower percentages but minimal. Cold can cause
a loss of as much as 20% in the cold. Add this to the lower SOC and you may notice it sooner.
Zero's latest SOC recommendation is for the bike being STORED. If you plan on riding in the next
days or weeks then a higher SOC should not be an issue.
Title: Re: Faltering acceleration on partial charge after sitting
Post by: Electric Terry on December 29, 2017, 05:22:41 PM
This is totally ok and completely normal behavior of cold batteries.  It will accelerate quick at slow speeds where power is low and torque is high but limit acceleration at higher speeds and limit the top speed you can go.  It is amplified the lower the SOC is.   If the bike sits for weeks and you know you want to ride it in a few hours, plug it in and top it off.  That easy.  But you are doing the right thing keeping it not fully charged while sitting for long periods weeks at a time.

When the batteries are kept cold and at a low state of charge, they lack the ability to deliver large amounts of power.  But this is also exactly what helps extend their calendar life.  When you want to ride, top it off and even bring it inside overnight to warm it up if you want.  But remember, the conditions that give you the most power (full charge, above 100F) are also the same conditions that degrade the battery the fastest.

Actual charge cycles and fast charging rates have very little to do with battery life compared to sitting at high SOC and/or hot temps.