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 doesn’t 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
Total time took for
0-80%, 4:20mins with 2.9 units.
0-100%, 5:35mins with 3.67 units.
These are some quality testings that you have conducted… Well done!
Awesome. TFS. This answers questions many folks have in mind. Quality post.
As per this, the scooter was changing at a rate of around 9.3% per 30 mins…
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%…
And I feel I’ve 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.
Thanks, hope this post will help existing and new owners
Average Line voltage at the time of charging?
I didn’t capture the voltage data for the whole session. But I’m sure it is in between 235-250, which is average voltage in my area.
Modern devices can compensate for voltage fluctuations with Ampere. It doesn’t matter much.
And rest assured for dot charger, it has wide acceptable voltage range.
The 100% shown on the screen wouldn’t be the actual 100% I believe.
Even when showing 100, it would probably be at 95 or something and rest filling up the buffer
What do you think?
Could be, but to confirm that someone should constantly check the screen during last 10%…
Also if that was true, let’s 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 it’s back to actual battery status
Yeah I guess… thats why you see sometimes the scooter drops to 99% after 200-300m of riding
Or sometimes stays at 100% after 1-1.2km (very rare)
Or maybe the buffer gets filled up first? Confusing
Hmmm… I’ll take this over the thought that battery is charging rapidly for last 10%…
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 doesn’t 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 screen…
I guess by gradually he meant is it doesn’t drop directly when you are trying to turn it off or once you reach 100%… I don’t think it’s related to decreasing during the charge cycle
It won’t make sense to do something like this tbh… People try to make things look fast but this would make the changing appear slow
Great to see insights behind the engineering at Ather
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 don’t think it is showing the wrong numbers. That’s 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.
Hope this clears few things.
That’s some good stuff @whomever97
About the units consumed i.e 3.67 KWh, please note that there is always transfer loss which is roughly 10%.
Which means to fully charge “X kWh” to 100%, you would technically need “X + ( 10% of X)” units.
Hope this clears out any doubts.
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