I wanted to analyze the charging characteristics of both Battery and Dot charger.
So, I drained my Ather 450x till the motor cut off.
This test was performed 2-3 weeks back and I forgot to make a post about it.
Odo reading at the time 625Km.
I used 2 different energy meters and tested their accuracy with my DMM. Both the meters were pretty accurate. Charging was initiated only after making sure that Battery and Motor were at the room temp.
Couple of observations -
Scooter kept on running approx. 500m even though battery percentage and range were showing as 0.
Scooter is super accurate about the range it predicts.
Total power consumed to full charge was 3.67 units (kWh), which is weird because I thought due to buffer it will only use 3.24 units.
Some observation about the charger -
Dot charger is designed extremely well. It doesnât give shock to electric system by directly shooting to 750W as the rated power. It raises power slowly and gradually and same thing happens when charging is done. It drops the power gradually.
The efficiency is crazy good. As per my calculations it is about 97-99% efficient with PF of near 1.
Same is explained very well in their blog, if interested give it a try. It is more on technical side but an interesting read indeed.
Link - https://blog.atherenergy.com/algorithmic-architecture-for-bms-d1fd9f5eb1b
So, here are the results, I checked on the meters at 30 min intervals.
30 min - 7
1 hour - 18
1.5 h - 27
2 h - 36
2.5 h - 46
3 h - 55
3.5 h - 65
4 h - 74
4.5 h - 83
5 h - 91
5.3 h - 100
As per this, the scooter was changing at a rate of around 9.3% per 30 minsâŚ
And for the final stretch it charged at 9% in less than 30 mins which shows that the charging speed was increased for the last 10%. Which is just the opposite of what fast chargers should do, fast chargers should ideally lower the charging speeds as you go beyond 80%âŚ
And I feel Iâve seen somewhere that Ather claims that even they follow this process⌠Weird
Yes, you are correct. That is exactly what I was expecting too. But as i said, they engineered their stuff very well. The charger gives consistent performance no matter what charging state the scooter is. Same was mentioned by Tarun when he was explaining new AtherStack at the Community Day.
I didnât capture the voltage data for the whole session. But Iâm sure it is in between 235-250, which is average voltage in my area.
Modern devices can compensate for voltage fluctuations with Ampere. It doesnât matter much.
And rest assured for dot charger, it has wide acceptable voltage range.
Also if that was true, letâs say you remove the charger as soon as you see it reachs 100%. That would mean that the scooter lied to you and you just charged it to ~95% resulting is degraded efficiency till itâs back to actual battery status
It would be better understood if there was a also a measurement of power consumption during the last 10%
However OP did say this. Since the power drops gradually (but the time taken doesnât increase) its safe to assume the % on screen is misleading near the end
Maybe the pack is at 95% but the screen shows 85% after which it slowly syncs them up and compensates for the difference by speeding up the % displayed on screenâŚ
I guess by gradually he meant is it doesnât drop directly when you are trying to turn it off or once you reach 100%⌠I donât think itâs related to decreasing during the charge cycle
Ok, this topic is catching pretty good heat. So let me clarify few things.
Battery is charging at about 9% per 30 mins.
For the last stint as well. In last 2 sessions, it charged 7% and 9% respectively. So, it is consistent. Kudos to Ather team for making such effective algorithms, hardware and cooling.
I donât think it is showing the wrong numbers. Thatâs why I also added the power consumption. So, as the battery is 3.7kW, same is showing up in units consumed. And if you calculate the 80% power of this, that is correct to the decimal point when the battery showed 80% on the screen.
I stopped the clock when it showed the charging is done. And then I observed the power dropping gradually.
I wonder how did it cost u only 3.67 units from motor cut off to 100% , I have uploaded a pic from my smart plug which I installed with my Dot charger yesterday to see the consumption, my scooter was at 30% and I started charging at 11:30pm and set a timer for 4.5hrs (4:00am power cutoff) , it costed me 4.76 units