Okay so, recently I came across a friend’s Ather Health Certificate and i couldn’t help but think about the battery health of his scooter
My scooter is about the same age with just about to hit 10k Km and I asked around to see what people thought about the 5% degradation and everyone seemed fine with it. But idk why but I couldn’t look past and I realized at this pace I’ll end up with 80% health or lesser in just under 5 years and that’s not what visioned for my 450. I know a lot of people would think 20% degradation in 5yrs is fine but bare with me.
On asking this owner I understood that he almost always charged to 100% overnight and maintained a 30/50 to 100% charge cycle. Which is what majority of users follow too. I didn’t want this myself but for the past 10k Km I’ve used the same 50-100% charge cycle. With overnight charging, which Ather recommends. I understand the logic behind recommending to charge overnight to make the ownership of an EV hassle free but the physics of the matter is that charging over night to 100% isn’t really good for our batteries. So I decided to find a way to start maintaining charge cycles farther away from 100. I purchased a smart plug. A 15A Wi-Fi enabled plug from Wipro.
At first I started with a scheduled charge of about 1hr and 10-20 mins, because my daily usage is between 20 and 30Km I usually end my day at 45-50% and the 1hr + of charge usually gets it up to 85-90% and right when it reaches 90% is when I start to use it and drain it down to about 65-70% reach my college and be back home with 45-59% charge left and it spends the rest of the day - about 14 hours at 50% state of charge. Omitting a few short runs. Which is the best SOC to stay at while in idle.
I used this method for a month and what I noticed was, I used to keep playing around with the time at which the charging starts so has to reach 85-90% before I need to unplug and use my scooter. This was because there were many days I ended up using my scooter for 30+ km and the battery dropped to 35-40% and the old schedule meant I woke up to a 75% battery and had to deal with the anxiety. So I needed a way to make sure I wake up to a certain set SOC everyday and without the fear of waking up to a half charged battery. The simple fix would have been, if Ather allowed us to set an upper limit while charging. But I found another way.
Our scooters(450) charge up to 84% at about 1kW pulling just under 5A of current
And once it hits 84% the power drops to about 850w pulling just under 4A of current.
The smart plug I have has basic automated functions which are based on factors like current voltage power. So I set up an automated function to cut off charging when the Amps drop to below 4A.
And it worked perfectly. Every charge, the battery would stop at exactly 84%. I usually need closer to 90% to start with so I made the function with a countdown timer instead of switching off directly. And after a few tries I’ve found the right time from hitting 84% that it takes to hit 90%.
There’s a small issue with this method too, which I dealt with with a simple change in the time that my automated program is effective. Because when the scooter begins to charge. The current slowly ramps up to 5A so for that time that it’s under 4A the charging wants to cut off, for which I had to set it in a way that the program is not running when the charging begins.
Here’s a few logs of the cut off working
So I’ve basically found a very elaborate way of setting a fixed charging limit on my scooter. Which probably could be done through an OTA 🤷 But just like my previous post based on something Ather COULD have done to save me the effort.