CAKE KALK& Battery Charging

Update August 20 2020

I have owned my & for just over a month. In that time the charging times have come much more in line with Cake’s marketing materials, 0-80% in 1.5 hours and 81-100& in 2.5 hours. In speaking with those who are more knowledgeable than me about battery charging and BMS systems (like 98% of the population) it appears that the BMS’ overall balancing of cells has reduced or eliminated my prior issues. Same range, just a much improved charging experience.

Battery and Charging
I have had what I consider to be inconsistent charging times/levels compared to Cake’s marketing materials. I have found that the alleged charging time of 0 to 80% listed at 1.5 hours and to reach 100% from 80% adds another one hour for a total of 2.5 hours to NOT be what I have experienced.

Cake’s Marketing: Charging 0-100% takes 2,5 h to charge in a standard outlet

Here are my lists of charging experiences:

I have been doing some range/battery charging testing this weekend and am scratching my head a bit. Yesterday I went on a ride. Here are the stats:

1. Total miles ridden: 18.7
2. Maximum speed during ride: 45.8 MPH
3. Average Moving speed: 25.6 MPH
4. Total moving time: 43:56 minutes
5. Ambient temp yesterday was 71 degrees F
6. I rode in level 3 power and regen the entire time during this trip.
7. My weight in gear is 180 pounds.

The route was on road only, varying terrain with uphill, downhill and flat sections, about equal for all three. Upon returning home I showed 2 bars on my display. I did NOT remove the seat to check the voltage or percentage of charge. I hooked up the charger and went inside. After dinner I went to check the bike and the fan on the charger was off and the second light was blinking, indicating the charger was completing a full 100% charge. About six hours later just before going to bed, I went back out and the bike was still charging on the blinking second light. So I shut everything down and went to bed.

This morning the battery level indicated 95% so I powered up the charger. After almost six hours the second light was still blinking and in seven hours the charger showed full.

July 27, 2020
I did a very short ride to my auto mechanic’s shop and when I returned home my display showed 3 of 5 bars left on the battery. I then placed the bike on the charger and started my stopwatch. I removed the battery so that I could photograph the battery and voltage levels:

After 6:07 hours the charger had not gone to full at which time I simply shut down the charger for the evening. The photographs of the battery level indicators above were taken just before shutting down the charger.

I should note that in several cases the bar display shows that I have xx number of bars before shutting down the bike. And when I am ready to ride (always during the same trip) when I engage the ignition the displays shows one bar more than when I shut the bike down.

I have notified Cake of these incidents and they are looking into it. Once I get definitive answers I will post them here.

July 29, 2020

On July 28 2020 I did a longer ride which involved up and down hills for a round trip of 22.8 miles. Level 3 regen and power levels during the ride. Upon returning to my home my display showed one bar, indicating 20% battery level remaining. So I placed the battery on the charger but this time instead of allowing the charger to remain on until it indicated “Full” I disconnected the charger at 3:03 hours. At that time the Charging LED (yellow) was flashing indicating that the battery had reached 80% charge and was being brought to 100%

The next morning, July 29 2020 I powered up the charger and activated my timer and at 2 hours and 43 minutes the charger indicated the battery was full:

So in this instance using the new method of disconnecting the charger at around 3 hours, reconnecting it the next day ‘seems’ to have topped off the battery according the both the charger indicator and the level meter on the battery. And NO Cake’s claim of 2.5 hours from dead to full is not what I’ve personally experienced in my ownership.

There is something not quite right about Cake’s charging to have this many variables occur. Sure when I’ve developed products in a former life I took into account user error, temperature, etc. But because I’m intimately familiar with those factors I’m very careful about ruling out those aspects.

Yep this Cake is half baked and under proofed in terms of the charging. The frosting and presentation is world class, but the electronic portion needs improvements.

August 4 2020

I did a final test of the battery charging and recorded video for time.

My Tripmeter

2 Bars remaining on the display after this ride which indicates 20% charge remaining:

51.9 volts remaining according to the battery display panel

54% of charge remaining according to the battery display panel

So it took over six hours to fully charge the battery which was 40% full on the display panel or 54% full on the battery level indicator…..

In the words of Paul Hollywood from the British Baking Show “This Cake is under proofed and under baked” when it comes to the battery charging indicators. I suspect that the BMS in the Cake ‘may’ be the culprit. I’m waiting to hear what Sweden’s engineers have to say….more to follow.

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4 Comments

  1. It sounds like there should be a “low fuel” light on the dash and a more accurate display. I can’t stand there 4 and 5 increment battery indicators. 20-25% increments are too rough, especially considering that I like to operate at between 40 and 80% to prolong the health and capacity of my batteries. Range is difficult to gauge, but with modern electronics it is relatively trivial to accurately monitor power consumption. The actual power available will depend on discharge rate and temperature, but those variables can easily be factored for. These refinements require extensive product development that is common for cars that sell 100K units a year, but unlikely on niche market products like the Cake. We are more likely to see evolution on the Sur Ron especially with Segway marketing the bike so heavily.

    1. Eli I agree I’d appreciate a more informative charge level indicator. I can appreciate that so many variables come into play with EV range but bars is a pretty crude measurement scale on this bike.

  2. Hi Mark, great write ups on the Cake bike, thank you for taking the time to document your experience in so much detail. Regarding the charging time, not sure if you are aware, but with the battery going to 100% indicated charge, but the charger is still charging, what may be happening is that the charging system is “balancing” the charge between individual cells in the battery once the charge gets to 100%. This is common practice with EV’s and is used to optimize the performance of the battery and to extend battery life. So, technically, the battery takes x amount of time to get to 100% charge, then the rest of the time is spent balancing the cells, which may not be technically considered charging time (and marketing will always tout the shorter time).

    I own an Alta e-dirt bike and that’s the way ours charge. According to Alta owners who are much more knowledgeable then me it is ok to ride the bike once it reaches 100% charge/before it finishes balancing, but it is better for the long term life of the battery to allow it to complete the balancing portion of the charge.

    I usually let mine charge/balance completely but on occasion I have stopped the charger in mid charge at whatever level it is at and everything seems to be just fine so far (this practice is not unusual with Alta owners from what I have been reading).

    I wonder what Cake’s recommendation is regarding stopping the charging mid cycle, or after 100% but not fully completed (balanced)?

    Anyway, thanks again for the write ups, I’m looking forward to learning more about the Cake bikes, hope you do some more posts. -Eddie

    1. Eddie I cannot express enough just how thankful I am for your explanations. I am an electronics dunce and don’t purport to be anything but that when posting here. So thank you that makes perfect sense to me now. One of the primary reasons I’m taking the time to document what I have experienced is the Cake community is pretty much non existent as far as I can tell. I am amassing an entire list of questions to send to Cake Utah and your point about ceasing the charge cycle before 100% will be part of that list.

      Thanks again, much appreciated!

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