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[ESokoloff]

52k miles & each winter seems to yield less from the battery but not seeing a drop in range but rather seemingly a reduction in intensity. 
I use the bike to commute to work (about 55 miles round trip) & charge at work.
Not noticing this on my afternoon leg home but that’s due to relative warm temps & high state of charge.
I arrive home in the afternoon with about 72% charge and the next work morning return on the remainder of the charge arriving at work with about 30% & then plug in for a full recharge by shifts end.
I’m finding that with the cool AM commute battery output (amps) increasingly reduces but it seems each winter it’s more noticeable then the last. 

As stated, range has not appeared to be drastically reduced as top speed is reduced & thus energy is saved.
Flat terrain is not too bad but much speed is lost when encountering a grade.

I’m assuming this is a battery issue as apposed to a BMS issue.

The bike will be 5 years old next June so I intend to have the battery condition assessed @ Hollywood Elect. before the warranty is over on the battery.

Any feed back would be appreciated.

Thx.

[Demoni]

Would put my bet on an increase in the internal resistance of the battery cells.
Since i=v/r higher resistance will reduce the available current output of the pack. This reduction in max current would be most noticeable when accelerating from a stop or climbing a grade.

I have not read the entire power pack warranty but I recall seeing an acceptable capacity loss threshold of 20%. Did not see anything related to what is considered an acceptable performance reduction?


Would be interested to here the results of the health test, best of luck!


 

[ESokoloff]

.....
This reduction in max current would be most noticeable when accelerating from a stop or climbing a grade.

Also when battery SOC is at its greatest/highest volts, amperage demand is at its lowest thus the lower the SOC, the greater the effect. 

I have not read the entire power pack warranty but I recall seeing an acceptable capacity loss threshold of 20%. Did not see anything related to what is considered an acceptable performance reduction?

Per the warranty info....
“ Zero will only repair or replace pursuant to this Limited Warranty a Power Pack that exhibits a nominal storage capacity reduction of greater than 20% of the published nominal capacity, as measured by an authorized Zero dealer.”

I’m hoping that output performance is taken into consideration.
In its present condition it’s not safe to ride on the freeways much below 50% SOC as any grade reduces top speed well below the limit (65mph).

[Crissa]

I would think that a reduction of available speed would demonstrate a definite loss of current out of spec.

-Crissa

[ESokoloff]

As has been pointed out, the internal resistance of the battery has likely increased somewhat. That is normal for 5 year old battery with what, 1000 cycles? Vehicle manufacturers cleverly offer warranty on battery capacity, not internal resistance. 
But also check for other resistances: Rolling resistance (tires (worn or low pressure tires can rob power), belt, bearings, brakes (dragging)), resistance in connectors (thermal cameras work beautifully for that). Faded magnets in the motor (if yours has permanent magnets).

Good guess on the battery charge cycles.
Actually it’s 1396 but if you take into consideration that my typical charge is 30-100 (70%) factor in a .7 multiplier yielding 977.

Regarding rolling resistance & faded magnets........
I’m finding that my afternoon commute battery performance & ending SOC hasn’t noticeably changed nor has the mornings ending SOC.
What’s changed is a significant drop in battery output amperage performance the further into my morning’s commute I go resulting in lower top speed.

My total commute is 50-55 miles & the amount of battery capacity varies due to ambient temperature.
If anything, this Winters SOC appears to be higher then normal but at the expense of amperage output performance.

[eddiebee]

I'm experiencing the same lowered-top-speed when my SOC drops.  My 2015 can now only go about 80mph at 75% SOC.

The problem is I'm on a Caribbean island and I'd have to ship my bike to a dealer thousands of miles away, which is basically not an option unless the bike stops working.

Any suggestions how to test the battery capacity using just logs, a voltmeter/ammeter, and maybe some coconuts?